OF iNsTlTUHUW u I... .. -._

Thesis {or “'30 Degree 0‘ M. S.
MICHIGAN STEVE UNIVERSETY

Robert West Gang
1959

 

¢ “‘5“,

, LIBRARY

Michign State
University

 

 

 

 

FACTORS IN THE SELECTION AND MAINTENANCE OF
INSTITUTIONAL FLOORS

By

Robert West Gang

A PROBLEM

Submitted to the Dean of the College of Home Economics
of Michigan State University of Agriculture and
Applied Science in partial fulfillment of the
requirements for the degree of

MASTER OF SCIENCE

Department of Institution Administration

I959

LIST OF TABLES.

PREFACE .

INTRODUCTION.

COMMON

TABLE OF CONTENTS

Resilient Floor Coverings.

Non-Resilient Floors

Comparison of Resilient Floor Coverings and

Asphalt tile .
Cork tile.
Linoleum .

Rubber

Vinyl.

Concrete

0

Hard tile.
Marble .

Oxychloride (m
Terrazzo
Wood

agnesite

Non-Resilient Floors .

L.ITERATURE CITED.

APPENDIX .

>2

TYPES OF FLOORS AND FLOOR COVERINGS.

ill

LIST OF TABLES

ASphalt tile color groupings. . . . . . . . . .
Effect of certain chemicals on concrete . . . .
Comparison of resilient floor coverings . . . .
Comparison of non-resilient floors. . . . . . .

Maximum safe load limit for resilient floor
coverings . . . . . . . . . . . . . . . . . . .

Resistance to indentation of selected resilient
floor coverings and non-resilient floors. . . .

Comparative cost of resilient floor coverings .

Comparative cost of non-resilient floors. . . .

PAGE

47
83
8:.

8A

85
86
B6

PREFACE

This manual was written for housekeepers, custodians,
and management specialists interested in floor selection and
maintenance. In l953, when I became Building Supervisor of
a group of Residence Halls, which were then under construction,
I knew little of floor maintenance and began searching for a
manual of this type. Although there were many publications
with sections devoted to floor maintenance, none provided
adequate information on that subject, or would serve as a
guide for selection of a floor.

The factual material presented in this report is based
upon information from the various trade associations listed
in the appendix, articles from the trade magazines, work with
other Building Supervisors, classes of Hospital Housekeepers
and School Custodians.I have taught and my own experience as
a Building Supervisor for six years.

The usefulness of this manual to the reader, depends
upon his degree of interest in flooring problems. For one
sincerely concerned in learning more about floor maintenance
and selection, this manual can be of value whether he is a
novice or has had twenty years experience.

Floor maintenance materials and methods may change in
the future. Manufacturers are constantly developing new
machines and new products. I have tried to list maintenance
methods in general terms with the thought that what is pre-

sented as true today will be valid in the future.

iv

INTRODUCTION

Whenever a new building is designed or an old building
is rehabilitated the selection of prOper flooring for each
area is of prime importance. This is particularly true of
institutional buildings since floors usually account for 3 to
lC percent of the initial building cost and receive at least
80 percent of the wear.

Flooring problems have no cure-all. There is seldom
one floor which will meet all service requirements in a parti-
cular institution; a flooring may perform well under certain
conditions and fail under others. Intelligent selection by
area and use is essential for maximum utility and life.

Too often, floors are purchased on initial cost alone
and low installation expense is the sole determining factor
in selection. A more reliable method of determining the true
cost of a floor is to consider the initial cost, the expected
life of the floor, cost of maintenance and the cost of repairs.
Cloyes (l2) has suggested a formula based on these factors for
comparison of flooring costs:

F + Y: + YR : Cost per square foot per year
F 2 First cost of flooring installed
Y = Expected life of flooring in years
M = Cost of maintenance per year

R = Cost of repairs

The application of this formula frequently provides concrete
evidence that the purchase of the cheapest floor on basis of
initial cost is false economy. The least expensive flooring
is often the most expensive to maintain.

Unfortunately, lack of money may be the executioner
after intelligent planning has included careful consideration
of initial cost, utility, expected life, maintenance and re-
pairs. Since the architect must remain within the building
appropriation, flooring specifications usually bear the brunt
of a budget reduction. Asphalt tile may be substituted for
terrazzo or ceramic tile and grease-proof asphalt tiie may
replace the initial specifications for quarry tile. No mater-
ial should be expected to do the job it was not designed to do
and it is seldom economical to buy the cheapest floor simply
because of low initial cost.

The purpose of this manual is to provide information
for intelligent selection and efficient maintenance of floor-
ing materials. To select the one best material is not the in-
tention of this report, but rather to point out the more im-
portant advantages and disadvantages of common types of hard
and soft flooring and to discuss their manufacture, installa-

tion, cost and maintenance.

COMMON TYPES OF FLOORS AND FLOOR COVERINGS

The first floors were tamped earth covered with textiles
or skins; later, different types of stone pavings were intro-
duced. During the Roman Empire (205 B.C. - A.D. iBO) small
pieces of marble were imbedded in cement to form terrazzo and
at the same time mosaic tile and marble floors appeared. In
the late i2th and l3th centuries tile floors became usual in
churches and other important buildings while wood floors were
common in homes.

An early forerunner of modern floor covering was floor
all cloth, which had its origin in a coarse fabric woven of
heap or flax coated with oil or paint (2}). Later, the cloth
was sized with liquid glue, rye flour, or varnish and the sur-
face was rubbed with pumice to make it smooth. A coat of color-
ed clay was.next applied to the surface which was then scraped
and evened to the desired thickness. Floor oil cloth, however,
was not satisfactory. The patterns faded rapidly and the cloth
frequently had to be replaced. The industry, therefore, set
about designing new materials which would be more satisfactory.

The development of resilient floor coverings such as
linoleum, asphalt, cork, rubber and vinyl has been recent com-
pared to marble, terrazzo and tile. The linoleum industry dates
back to l860 with the invention by Frederick Walton of the pro-
cess for oxidizing linseed oil. Rubber and cork fioorings were

first manufactured around l900, asphalt tile was introduced in

l922 and vinyl floors made their public debut at the Chicago
World Fair in I933. Mass production of the currently popular

asphalt tile and vinyl floorings did not begin until the time

of World War II.

Resilient Floor Coverings

There are five basic types of resilient floor coverings.
These are: aSphalt tile, cork, linoleum, vinyl, rubber and
combinations of the basic types. The wide use of resilient
floor coverings has been due to these product characteristics:
(i) Easy and economical installation.

(2) Availability of wide variety of sizes, colors and
patterns.

(3) Maximum floor comfort.

Asphalt tile

There are probably more square feet of asphalt tile in
institutional, industrial and commercial buildings today than
any other kind of resilient flooring. This is primarily due
to ease of installation and low initial cost.

The continuous growth of the asphalt tile industry is
shown by the increase in annual production from an estimated
3 million square yards in l930 to Al million square yards in
i947. The l952 production of 80 million square yards accounted
for an estimated lO-l2 percent of the resilient floor industry.

Manufacture and cost. Commercial manufacture of asphalt
tile began in i922 when a midwestern manufacturer of asphalt
roofing products started the production of asphalt tile. An
early process involved a heavy asphalt solution containing miner-
al fillers troweled smooth and allowed to harden by evaporation

of the solvent (23). At first, tile colors were limited to

black, red, brown and green. Production of individually molded
tiles was practiced initially, but this was soon superseded by
the present process of sheeting and cutting to size.

Asphalt tile is a thermoplastic material consisting of
asbestos fibers, mineral coloring pigments, inert fillers, asphal-
tic and resinous binders. These constituents are mixed, calender-
ed, sheeted and cut. The binder materials determine the physical
properties of the tile such as flexibility, resistance to in-
dentation and resistance to heat and light (23). The binders
also affect the chemical properties of the tile such as resis-
tance to alkalis, acids, greases and moisture. The fillers con-
sist of asbestos in fibre form and mineral aggregrate (clay,
ground limestone, and ground sand). Different formulations
produce different qualities of the manufactured tile. The
pigments used are generally selected for light fastness, alkali
and acid resistance, as well as to produce the desired color
in the tile.

Asphalt tile is sold in a series of color groupings,

A, B, C or D which are described in Table l. A and 8 usually
contain asphalt binders while C and D have the resin binders
(9). Asphalt tile is also furnished in a grade designated as
Greaseproof. In the case of dark colors, the binder is Gil-
sonite asphalt. One of the paradoxes in product naming is

found in the case of the intermediate and light colors of
asphalt tile: color groups C and 0 contain little or no aSphalt

since resins are the binders.

TABLE l

ASPHALT TILE COLOR GROUPINGS

 

 

 

Group Colors Description
Color Group A Black, dark red Plain colors only
Color Group 8 Background colors black, Marbelized colors

dark brown and dark red only

mottled with any one or
more of the following
colors: white, red,
yellow and green.

Color Group C Dark green, light green, Plain colors
light gray, light red,
medium red, tan and buff.

Seven background colors Marbelized colors
corresponding to the plain

colors listed above, mottled

with any one or more colors

to make seven color patterns.

Color Group 0 Cream, white, blue Plain colors

Three background colors Marbelized colors
corresponding to the plain

colors listed above mottled

with any one or more colors

to make three color patterns.

 

ii

Asphalt tile is regularly available in sizes 9 by 9 inches,
l2 by l2 inches, and l8 by 24 inches with either l/B-inch or
3/l6-inch thickness (3). The 3/l6-inch thickness is often
used in industrial establishments where floors receive a great
deal of wear and abuse. The 9 by 9 inch tile is the most com-

monly used.

While the cost of asphalt tile has increased with ris-
ing prices generally, it is still the least expensive of the
resilient floor coverings. The initial cost of the asphalt
tile varies with the colors selected.

Group A colors are usually lowest in cost.

Group B colors are usually next lowest.

Group C colors are usually next lowest.

Group D colors are the most expensive.

Of all the resilient floors, conventional asphalt tile
is the least expensive to install. Installed price ranges are,
however, difficult to quote because there are so many factors
that affect cost in addition to purchase price of floor cover-
ing material. Installation is often a major variant in floor
covering costs (l9). For example, a floor in a single color
and styling laid wall to wall is less costly than a complex,
custom designed floor that involves exceptional craftsmanship
and additional time to lay. Other items affecting installation

cost are subfloor conditions and local labor rates.

installation. Asphalt tile can be installed on nearly
any kind of subfloor almost anywhere, but it is not recommended
for outdoor installations (35). The subfloor, must be solid,
level, smooth, and free of wax and oils. If painted, the old
paint should be removed and the subfloor must be dry and not

at any time subjected to excessive moisture.

If the subfloor is concrete, and if any dusting exists,

a priming of asphalt should be applied. No under layment is
required if the installation is to be over a wood floor (4).
The wood subfloor must be solid and smooth, free of cupped or
broken boards. Sanding is sometimes necessary. The asphalt
tile adhesive should be applied in a thin film and spread even-
ly with a cement finisher trowel of the type suggested by the
asphalt tile manufacturer.

The ASphalt Tile Institute recommends a 70° F. room tem-
perature for a period of 48 hours before and during installation
followed by a 48 hour period at this same temperature after in-
stallation. Newly installed asphalt tile should not be scrubbed
for at least l4 days so that the cement bonds the tile tightly
to the subfloor and the tile sets solidly.

Complete information covering the installation of asphalt
tile has been published by the Asphalt Tile Institute, lOl Park

Avenue, New York City, New York.

Utility. The chief advantages of aSphalt tile, low
initial cost and ease of installation, have already been cited.
Universal popularity may also be attributed to:

l) Wide range of available colors and patterns.

2) Ample choice of tile sizes and gauges (thicknesses).

3) Fair resistance to alkali.

4) Easy replacement of damaged areas.

IO

Disadvantages of asphalt tile are readily apparent in
an institutional floor:

I) High maintenance cost.

2) Poor resistance to grease.

3) Poor resiliency compared to rubber.

A) Susceptibility to indentation.

5) Susceptibility to cracking or breaking when cold
and brittle.

6) Color fading caused by highly alkaline cleansers.

7) Softening and warping of the tile and loosening
of the adhesive caused by excessive use of hot water.

Maintenance. The basic steps in the maintenance of
asphalt tile are dry cleaning, wet cleaning, and, waxing and
polishing.

l) Sweeping, vacuuming or dust mopping are the usually
dry cleaning methods.
No floor should be scrubbed until it has been dry
cleaned by one of these three methods. Oil and its
derivatives can soften and disintegrate asphalt tile.
Care should be taken not to use an oily dust mop or
sweeping compound.

2) Wet cleaning. Three operations (stripping, scrubbing,
wet mopping) comprise the wet cleaning process.

a) Stripping. The removal of all soil and wax from
the floor with a soap or detergent
and mechanical agitation such as a
power scrubber.

b) Scrubbing. The removal of all soil but wax.
Many custodians use this term synono-
mously with stripping.

c) Wet mopping. The use of a mop and water on the
floor. Soap, detergent, or wax may
be added to the water. When wax is
added to clean mop water, this is
sometimes referred to as track mopping.

Certain precautions should be observed in all three
phases of the wet cleaning process.

a) New floors should not be flooded with water
until they have set prOperly, which may require
from 7 to i4 days.

b) The excessive use of hot water or too much
water may cause warping or softening of the
tile. The water may also loosen the tile from
the mastic which binds it to the subfloor.

c) Highly alkaline soaps can cause bleeding or
loss of color by damaging the pigment binders.

d) Rough steel wool can scratch the tile.

3) Waxing and polishing. Only good water emulsion
waxes or plastic coatings should be used on asphalt
tile. Solvent waxes will soften and deteriorate
asphalt. The wax should always be applied in thin

coats and the floor should be machine buffed after

each coat is dry. If a slip hazard exists, slip
resistant waxes are available.

Cork tile

Although cork tile has been manufactured since l9OO it
constitutes a relatively small part of total industry production
(23). This may be due to the restricted use and high price of

cork floor coverings.

Manufacture and Cost. Cork comes from the outer bark
of the cork oak tree found in Spain and Portugal and is com-
Dosed of numerous i4 sided cells which are empty. The bark is
converted into shavings, cleaned, ground, molded in large hy-

draulic presses and sheeted. The sheeted material is then

l2

baked at a high temperature to melt the natural resins which
bind the mass together. Some manufacturers add certain resinous
binders of lower melting point to reduce the baking temperature.
The surface of this sheeted material is given a heavy coat of
melted wax and the sheeting is cut in various sizes and sold
as cork tile.

Cork tile is available in light or dark brown tones and
in a variation of shading which is fabricated by mixing dark
and light particles of cork in the same tile. The tile may be
purchased in squares or rectangular planks and is usually in-
stalled in alternating shades.

Of the resilient floor coverings only pure vinyl tile
is more expensive than cork. Rubber tile is nearly equal to
cork in price but linoleum, asphalt tile and vinyl asbestos

tiles are cheaper.

Installation. Cork tile should be installed only on
floors which are above ground and ventilated underneath (45).
Most basement installations are not feasible since cork tile
should not be laid on subfloors in direct contact with the
ground or over concrete floors subjected to moisture. While
the cork componets of the flooring are not affected by ordi-
nary moisture, the resinous binders and the cement which attaches

the tile to the subfloor are likely to deteriorate from prolonged

contact with moisture.

l3

Cork tile is flexible and will bend several degrees be-
fore breaking. The natural tendency of the tile to promptly
resume its original shape makes it less adaptable to uneven
surfaces than other resilient floorings. When an installation
is made over an uneven subfloor, sanding of the cork may be
required to avoid an undulating appearance and normally the
tile will loosen.

For a satisfactory installation certain precautions are
essential. Plywood or masonite (fi-inch) should be nailed to
old subfloors with screw type nails on 6-inch centers and on
3-inch centers along the joints. In the case of new wood sub-
floors the boards should be well seasoned and well dressed,
not more than 3 inches wide and laid perfectly smooth with all
joints tight and well nailed. Wright (43) has recOmmended that
an asphalt saturated paper with butt joints be laid across the
boards and cemented down. A newly sanded wood subfloor may
be given a coat of penetrating floor sealer to insure better
adhesion of the cement which attaches the cork to the subfloor.
Cork tile should not be laid over a single-layer floor since
some single-layer floors may flex under pressure and thereby
loosen the tiles.

Professional installation of cork tile is advisable

even though specifications and directives are available from

manufacturers.

Utility. Cork is the luxury floor of the resilient

l4

floor coverings. It is similar in composition to linoleum
but it is lighter, more resilient and less durable. Because
of composition cork tile is extremely flexible, very quiet,
soft and easy underfoot and for these reasons is used where
comfort and quietness are primary factors. Cork is not recom-
mended for such areas as kitchens and dining rooms.
In the selection of an institutional floor the advantages
and disadvantages of cork tile should not be overlooked.
Advantages
l) Comfortable for standing or walking.
2) Absorption of traffic noises.
3) Easy replacement of damaged tile.

4) Good coefficient of friction; normally slip
resistant.

5) Good insulator against heat and cold.

6) Resistant to mild acids.

Disadvantages
l) High initial cost.
2) Expensive and difficult maintenance.
3) Poor resistance to solvents and grease.
A) Easily indented.
S) Easily damaged by excessive hot water.
6) Scratching from abrasive cleaners or gritty soil.

7) Deterioration by highly alkaline cleaners.

Maintenance. Cork tile is not designed for rugged

'5

usage, but may, if properly cared for, last for thirty years

in areas such as offices or homes (45). On the other hand,
abuse, neglect or incorrect maintenance may limit the life

to less than five years in areas such as hallways or ballrooms.
Cork tile should not be scrubbed for 7 to lb days after in-
stallation and then with a rather neutral soap.

Remember that:

l. Vacuuming, sweeping, or dustmopping may be used
in dry cleaning cork tile.

2. In wet cleaning, use only enough saopy water to
loosen the soil and remove immediately with a wet
vacuum pickup.

3. Cork tile may be waxed with either solvent or
water emulsion wax, buffing after each coat.

4. Machine buffing with #00 steel wool is sometimes

employed for the cleaning process.

Do not:
I. Use harsh alkaline cleaners.

Use harsh abrasive cleaners.

. Clean with naphtha, gasoline or similar solvents.
. Use oily dust mops or oily sweeping compounds.
Coat with a varnish or lacquer.

Concentrate heavy loads on small areas.

Use excessive water.

CDNOUTIT'UM

. Allow grit, sand or cinders to accumulate on floor.

Linoleum

Linoleum, a term originally coined by the Englishman
Frederick Walton for a material of his own invention, is now
used indiscriminately to describe almost all floor coverings
having a base of solidified oil adhering to a jute canvas or
some other foundation (23).

The earliest patent in i636 for "Painting with oyle
cuiiers upon wollen-cloath," was recorded in England (24).

In l754 Nathan Smith established a factory at Knights Bridge
for the manufacture of floor cloth by applying a mixture of
rosin, pitch, Spanish Brown, beeswax and linseed oil in a
melted state to canvas and rolling it in by pressure (23).
Ninety years later Elijah Galloway softened India rubber by
heating, incorporated it with cork dust, and rolled the re-
sulting mass into sheets which were marketed as "Kamptulicon".
Owing to the high price of rubber, the floor covering proved
to be costly; and in l860 Frederick Walton invented a process
(Eng. Pat. 209) for oxidizing linseed oil to produce a cheap,
rubber-like substitute (23). In principle, the methods used
today are essentially the same as those covered by his in-
ventlons.

Production of linoleum was well under way in England
and Europe by the latter part of the nineteenth century. In
the United States the linoleum industry has tripled production

dUring the last forty years to an estimated current production

l7

of nearly l00,000,000 square yards in l958. It is computed
that the world's output of linoleum is more than 200,000,000

square yards per year.

Manufacture and cost. The principle ingredients for
the manufacture of the surface of linoleum are oxidized drying
oils (linseed and soya bean) incorporated with rosin or resins.
and cork or wood flour (23). From the drying oils linoleum
receives wearing qualities while the resins act as a binding
material. Resiliency and heating properties are obtained from
the cork and wood flour.

The manufacturing processes for linoleums are essentially
the same as those invented by Walton and involve the following
operations:

I. The production of solidified linseed oil.

2. The manufacture of the cement.

3. The incorporation of ground cork or wood flour and

pigment with the cement.

A. The application of this mixture to a backing of

burlap, cotton or asphalted felt.

5. Seasoning or curing of the sheeted material.

6. The painting of the underside to preserve the canvas.

7. The trimming of the finished cloth.

The first operation consists of a process whereby the
oil, driers, rosin and added gums are heat-fiuxed and then
placed in a horizontal, totally enclosed, jacketed, steel cylin-
der called a Bedford kettle. Conditioned air is introduced
through a port and high-speed agitation is provided by a hori-

zontal shaft equipped with radial rods. The resulting mass

emerges in a jelled form and is dumped onto a wood-flour

l8

covered floor in layers approximately two inches thick. After
cooling, cutting into small, rubber-like slabs, and a suitable
aging period, the linoleum is ready to use.

The next stage of the process involves the incorporation
of the cement with cork dust or wood flour, whiting, and pig-
ments in a steam-jacketed internal mixer. The mixture then
passes through a series of large grinders and the extruded
product is fed into the "scratcher", a machine consisting of
two rolls, one steam-heated and the other cold, to which the
material adheres. Adjacent to the "scratcher" is a third roll,
fitted with hundreds of sharp spikes, which revolves at a high
speed scratching off small particles of the linoleum material
and converting it into granular flour. These granules or
"scratch" provide the basis for all types of linoleum (23).

The various products made from "scratch" can be divided
into three broad classes: plain, inlaid and printed.

Plain linoleum is all one color and has been popular
for institutional use in the ”battleship" type. This was re-
ferred to as "battleship" linoleum because it was first used
on the deck of warships. The original "battleship" linoleums
Were &-inch to fi-inch thick, today the usual thickness is
One-eighth inch.

Inlaid linoleum, sometimes referred to as embossed
inlaid, is often produced with imitation tile patterns. Since

the design and color 90 entirely through the backing, the

'9

pattern remains intact during the life of the covering. It
is often used in offices.

Printed linoleums are not practical for institutional
use since the design is stamped or applied with heavy lacquers
on the surface. They do not stand up in heavy traffic areas.

Linoleums are available in two, three, four and six
yard widths; thickness is usually between .0625 and .l25 of an
inch. Most linoleums are manufactured in rolls six feet wide
and ninety feet long to permit installation with as few seams
as possible (24). Occasionally the sheets are cut in tile
form.

The installed cost of linoleum varies with the type of
subfloor and the style of linoleum. If the subfloor is rough
the necessary adhesive and felt liner increase the cost. In
general, linoleum is the second cheapest floor covering in
terms of initial cost. In most areas of the United States

only asphalt tile flooring can be installed at less expense.

Installation. Linoleum can be installed over almost

any kind of smooth, solid, dry subfloor except concrete which
is in direct contact with the ground. The natural alkali in
concrete when activated by moisture tends to emulsify the oil
content of the linoleum. The resulting seepage can cause
disintegration of the backing material and slow disintegration
0f the linoleum itself. Since dampness is detrimental to lino-
‘etmu the subfloor should be at least l8 inches above the

grwsund for necessary ventilation (2A).

20

A solid subfloor is essential because a foundation
which flexes under pressure may cause the linoleum to break.
Holes, cupped boards or other imperfections in the subfloor
will soon become evident after the linoleum has been laid.
Such a subfloor requires sanding.

If linoleum is installed over single wood floors, hard-
wood or plywood should be laid first; if over a double wood
subfloor, the top floor should be tongue-and-groove. Cracks
wider than one-eighthof an inch and holes larger than one-
fourth of an inch should be completely filled with a good
plastic wood or snugly fitting pieces of wood. Loose boards
should be nailed down and the nail heads countersunk.

Lining felt is often used when burlap-backed linoleum
is installed over wood subfloors. Linoleum adhesive is
applied to the subfloor, spread out with a saw-toothed trowel
and the lining felt pressed down. After the floor has been
covered with the felt and the edges have been carefully butted,
a heavy roller is used to level the surface. When the lining
is firmly set, the adhesive is spread over the surface. Lino-
leum should be laid carefully in the same direction as the
lining felt but the linoleum seams should not cover the seams
of the felt. After installation the linoleum should be rolled
to insure thorough adhesion.

Wright (43) has recommended that linoleum be stored at
a teamwrature of 70° F. for at least 24 hours before installa-
tio" and that the room temperature during installation be at

”set 70° F.

2|

Before installation of linoleum on old floors the
quarter round moldings should be removed, the floor should be
stripped of paint, varnish and floor wax, scrubbed and thorough-

ly dried.

Utility. After one hundred years of use as a floor
covering, linoleum, the original resilient flooring, ranks high
in popularity with the residential building trades and has main-
tained qualified acceptance for institutional floors. Many pub-
lic buildings have not replaced the old "battleship" linoleum
floorings which were produced in é-inch thickness years ago.

In addition to durability, resiliency and quietness
linoleum has the following advantages:

l. Low initial cost.

2. Easy installation.

3. Availability of many types, patterns, and gauges.
4. Underfoot comfort.

5. Reelstance to indentation.

6. Resistance to grease and mild acids.

The disadvantages of linoleum are readily apparent in
certain institutional floor layouts:

l. Linoleum with burlap backing can seldom be in-
stalled on concrete.

Linoleum can be ruined by strong alkalies.

Worn areas cannot be easily patched.

Rough spots in the subfloor may damage the linoleum.
Abrasive cleaners may scratch linoleum.

Some types break or crack rather easily at low
temperatures.

O'iUT-PUM

Maintenance. The same rules governing the use of clean-

ers apply to nearly all types of linoleum (37).

22

Strong alkalies should not be used on linoleum. The
linseed oil component of linoleum is a vegetable fat saponifi-
able by alkali; consequently, alkalies of all kinds are injuri-
ous to linoleum. Even the natural alkali in concrete, when
activated by moisture, can disintegrate linoleum.

Too much moisture is detrimental to linoleum. Accord-
ing to some linoleum people more linoleum floors are washed
out than are worn out. Newly installed linoleum should not be
scrubbed until the adhesive cement has set which may require
five or more days. In washing or scrubbing only enough water
should be used for effective cleaning. Water may seep under
the linoleum and cause the backing to rot and the surface to
buckle and break.

Except in extreme cases abrasive cleaners are not
practicable for linoleum. Mild abrasives are sometimes used
for stain removal or to cut wax deposits.

Steel wool is occasionally employed for stripping old
wax, but may scratch the linoleum surface.

Either water or paste wax will provide a protective
finish for linoleum floors; neither type of wax should contain
any alkali.

Maintenance precautions can be briefly summarized:

l. Beware of highly alkaline cleaners.

2. Use only neutral soaps or detergents.

3. Be sure to remove all soap or cleaner after scrubbing
the floor.

23

4. Do not:

a. Use harsh scouring compounds.

b. Use sweeping compounds containing oils, sand
or abrasives.

c. Use sealing compounds except those recommended
by linoleum manufacturers for restoring the
appearance of an old linoleum.

d. Use too much water in cleaning linoleum floors.

e. Leave water or washing solutions of the floor
for any length of time.

5. Linoleum should be protected against indentation
by glides and supports.
Rubber

The English word rubber was coined by Joseph Priestley,
the discoverer of oxygen, from its use in rubbing out pencil
marks. The term India rubber was given because it was first
brought to Europe from the West Indies.

A factory for the production of rubber was in operation
in France in l803. However, the real development of rubber manu-
facturing began in England in l820. Thomas Hancock, often referred
to as the "Father of the Rubber Industry", opened a shop in Lon-
don in l820 and is credited with many of the early developments
in rubber manufacturing.

Rubber was first manufactured in the United States in
l832 but production was limited. In l870, B. F. Goodrich, the
discoverer of vulcanization established a factory at Akron, Ohio.
With the exception of World Wars I and II, rubber has been in
continuous production ever since.

Rubber flooring was first manufactured around i900 and

24

production has gradually increased from one million square yards
in l939, to around fifteen million square yards in l958. However,
rubber still constitutes a relatively small percentage of the

resilient floor coverings.

Manufacture and cost. When the Japanese cut the crude
supply of rubber from the Far East after Pearl Harbor, natural
rubber floors went temporarily off the market. Before World
War II much of the crude rubber had been imported from Malaya,
Borneo, Sumatra and Java.

Germany had developed a snythetic rubber in World War
I but since it was inferior to natural rubber, interest waned
when the war was over. Little work was done in the United
States on synthetic rubber until l940 when B. F. Goodrich and
Standard Oil each developed a snythetic rubber. The real im-
petus for devei0pment of snythetic rubber in the United States
dates to December 7, l94l. Numerous synthetic rubbers have
been developed since l94l; three important types are:

l. GR-2. (78 parts butadiene, 22 parts styrene)

2. Butyl. (97 parts isobutylene, 3 parts isoprene)

3. Neoprene. (monovinylacetylene)

Some of the ingredients in synthetic rubber might also
be found in plastic vinyl floor coverings. In fact, it might
be argued that synthetic rubber is a plastic, since it can be
fabricated by procedures used in manufacturing plastics. How-
EVGF. synthetic rubber is not considered part of the plastics

industry even though the preparation of the polymeric rubber

25

molecule is similar to the processes used in the development
of resinous polymers.

The manufacturing process for rubber flooring involves
the mixing of ingredients (clay, rubber, colors and accelerators)
in a Banbury mixer and/or in a differential-speed, two-roll mill.
The mass then passes through sheeter rolls. The sheeted mater-
ial is vulcanized in platen presses to obtain a high surface
gloss and is then cut to die presses. The final sanding oper-
ation controls the gauge and roughens the back surface for adhe-
sion during installation. Variations in pattern depends upon
the method of calender feed-preparations; i.e., the system for
overlaying contrasting color stocks to a base-colored stock in
the form of sheets (23).

Recent improvements in rubber tile production include
(i) a catalyzing agent which hastens the vulcanizing process
and consequently cuts manufacturing costs; and (2) the dis-
covery of several ingredients which guard against oxidation and
deterioration by ultraviolet rays of the sun (l8). Some authori-
ties disagree on the effectiveness of the latter develOpment.

The two main types of rubber flooring are rubber tile
blocks and sheet rubber which comes in rolls and is laid in a
manner similar to linoleum. Rubber flooring is usually avail-
able in thicknesses of one-eighth inch, three-sixteenth inch,
one-fourth inch and three-eighths inch.

Rubber flooring has many of the advantages of pure

26

vinyl and is usually more economical. The initial cost of
rubber floors is generally medium to medium high compared with

the other reSilient floors.

Installation. Rubber tile can be installed satisfactor-
ily over any solid, smooth, dry, ventilated subfloor, provided
the subfloor is free of dust, oil, grease, floor wax or other
foreign matter which may prevent proper adhesion (43). For
years, the recommendation has been made that no rubber should
be installed on subfloors in direct contact with the ground.
Concrete has always been an extremely poor base since the alkali
in the concrete may attack the adhesive which binds the tile to
the subfloor. However, a new adhesive has recently been develop-
ed which is satisfactory for binding rubber to concrete in base-
ments (40).

Rubber tile is usually installed in much the same manner
as asphalt tile. After the adhesive has been spread and set,
the method for laying tile is the sequence for most resilient
tile fioorings:

l. Make a chalk-line from the center of each wall to
the Opposite wall. This forms a cross, the center
of which, is the center of the room.

2. The tiles are laid along the line, beginning in the
center. Follow the line to each of the two adjoin-

ing walls but do not cement the tile down.

3. After the same margin has been obtained on all
sides of the room the tile is cemented down.

4. One quarter of the floor should be completed at a
time.

5. The entire floor should be leveled with a roller.

27

Additional information on installation is available
from the Rubber Manufacturers Association, 444 Madison Avenue,

New York 22, N.Y.

Utility. Rubber has for a long time been considered
the aristocrat of floors, and this is for good reason. Rubber
tile seldom gives cause for complaints for slipperiness. Rubber
flooring is resistant to cracking or crazing and high tensile
strength prevents excessive contraction and expansion, thus
eliminating the tendency to buckle. Rubber tile will withstand
200 pounds per square inch, whereas 25 pounds is considered the
limit for asphalt tile, 40 for cork tile, and 75 for plain lino-
leum (43).

Vinyl plastic at the present is a real competitor of
rubber tile despite the greater resiliency and lower price of
rubber. To distinguish rubber from pure IOO percent vinyl is
difficult; smelling is one test. Rubber has a particularly
characteristic odor when even a small amount of natural rubber
is used, while pure vinyl has practically no odor. The chief
merits of rubber are:

l. Relative quietness due to a low sound factor.

Resilience for underfoot comfort.

. Good service life when properly maintained.
Easy installation.

Possible replacement of damaged tiles.

0\ \fi 3' \N h.)
0

. Availability of wide range of colors, sizes and
thicknesses.

28

7. Good recovery from indentation.

8. Moderate resistance to acids, alkalls and staining.

Rubber tile floors also have disadvantages. The National
Bureau of Standards exposed 60 samples of rubber flooring near
a window for six months. A summary of the data gives evidence
that sunlight can be harmful to rubber floors:

An examination at the end of this period showed

that every sample had lost its gloss and in most

cases the surface had chalked as is most often

observed on painted surfaces exposed to sunlight.

In addition, most of the colors had faded to a

greater or less degree and in several cases,

there was surface checking. . . .1

Two other disadvantages of rubber for institutional
floors should be mentioned:

l. Poor resistance to grease and solvents.

2. Cracking due to prolonged air exposure.

Maintenance. Rubber floors, when correctly maintained,
will give years of satisfactory service from the standpoint of
appearance, durability and economy. Correct maintenance is a
vital requirement for full enjoyment of this type of floor.

Present day synthetic rubber tile is more resistant
to abuse than the pre-war natural rubber product, but is sus-
ceptible to injury from improper care. Maintenance rules for

the old type floors are applicable to the new synthetic floorings.

IBrenn, Earl. Floor maintenance manual. Huntington,
Indiana. The Huntington Co. p. X-l.

29

Rubber floors should not be scrubbed until they have
been laid for several days. While the adhesive is setting the
flooring should be protected against traffic. Heavy paper over-
lays can help prevent scratching or the tracking in of dirt,
grime and plaster. After the rubber tile is thoroughly set
the surface should be cleaned with a detergent approved by the
Rubber Manufacturers Association. Certain types of cleaners
and waxes have proved their suitability for use on rubber floors
and appear in List No. l5 from this Association (36).

Clear water mopping is a common method of daily main-
tenance for rubber tile since the plate finish offers little
refuge for dirt. However, when detergents are necessary they
could be selected from the approved List No. l5 prepared by
the Rubber Manufacturers Association in the publication, Approved
Maintenance Methods for Rubber Floors. \

Practically all manufacturers of rubber floors recommend
waxing with a water emulsion wax; paste or solvent waxes are not
practical. A good water emulsion wax will brighten the colors
of the tile, add to the gloss and make the floor easier to cleanT
and keep clean. The main purpose of wax is the protection of
the floor from wear since wax is easier to replace than the
flooring. A good wax coating will also safe-guard rubber against
twc'enemies, sunlight and air. The daily buffing of a waxed
floor with a polishing machine removes- much of the soil and re-
Vives the appearance. Ordinary traffic dirt and stains do not

readily penetrate a good film of. wax.

30

Because of the sensitiveness of rubber to oils and
greases, oil-treated dust m0ps or sweeping compounds should
never be used.

Any type of varnish or lacquer will cause hardening or
breaking of rubber and should not be applied.

Although rubber floors do not indent as readily as
some resilient floors, casters and glides should be used on
furniture.

Further information on the maintenance of rubber floors
is available from the Rubber Manufacturers Association, 444

Madison Avenue, New York, N. Y.
Vinyl

Hundreds of plastic materials have been developed since
John W. Hyatt discovered a synthetic plastic, celluloid, in
l868 (23). Although the first vinyl plastic floor was installed
in l933, this type of flooring has been popular only since World
War II.

The initial development of plastic-type floors was slow
due to the high cost of synthetic resins but the increased utili-
zatlon of resins in floor coverings and other products has helped
reduce prices. In l94l 23 million pounds of vinyl resin were
produced at a price of 77 cents per pound. It has been estimated
that over 500 million pounds were produced in l958 and the price
has decreased to less than 40 cents per pound. The floor cover-
'"Sl industry currently uses about l5 to 20 percent of vinyl resin

production.

3i

No official figures are available for total production
of plastic floor coverings. Some manufacturers have utilized
vinyl resins in improving conventional products, thus disguis-
ing the total impact of the new materials. Some estimates have
been that total production of all vinyl-type floor coverings
currently amount to more than half the yearly production of

asphalt tile.

Manufacture and cost. The term vinyl covers a wide
variety of floor types. Vinyl plastic, or resin, is a definite
material made from acetyline and hydrochloric acid which is
frequently used in combination with other raw materials. These
may include asbestos, asphalt, certain mineral fillers and even
ground cork (43). .

The physical and chemical properties of vinyl resins
are very adaptable to floor coverings. These resins are pro-
duced in powdered form capable of blending with plasticizers,
coloring pigments, stabilizers, and similar substances in a
Banbury mixer. This differential-speed, two-roll mixer is the
same type as that used in the rubber industry. After calender-
ing, the product is pressed on a base; neither heat curing nor
vulcanization is necessary. Plastic coverings are made both
in the integral and membrane forms. The membrane base consists
of asphalt-saturated felt, fabric, cork, or sponge rubber.

Pure, lOO percent vinyl floors have many desirable

qualities and are the most expensive of the resilient floors.

32

Consequently, some of the less essential virtues of pure vinyl

may be relinquished to produce other types of vinyl floors at

competitive prices.

Vinyl plastic floor coverings manufactured at present

include (22):

Rotogravure printed yard goods is made by print-
ing a photographed design with vinyl ink on a
heavy paper which is in turn water-proofed, lami-
nated to an asphalt saturated base, and finally
covered with a transparent layer of vinyl plastic.

A commercial product sold under the brand name
of Sandran is representative of rotogravure
printed yard goods.

Calendered vinyl flooring is the counterpart of
conventional inlaid linoleum. In this type of
plastic flooring the oxidized drying oils or
linoxyn are replaced by vinyl resin and plasti-
cizer. Calendered vinyl flooring is produced hi
both tile and yard goods form.

Gold Seal Vinyl-Floor is one brand available.

Semi-regid vinyl base tile is comparable to
aSphalt tile except that vinyl type resins
replace the asphalt, coumarone-indene or

other cheaper resins. Semi-rigid vinyl tile

is generally a little more flexible and resili-
ent than aSphalt tile.

Two examples are Terraflex and Koroseal.

Flexible vinyl tile, sometimes referred to as
pure or lOO percent vinyl is similar to rubber
tile in its flexible properties and is diffi-
cult to distinguish from rubber in appearance.
This type usually contains a minimum of asbes-
tos fiber, if any, and a lower loading of inert
pigment and extended filler. Some manufacturers
are laminating flexible vinyl type material to

a backing material.

Wingfoot and Lifetime Vinyl are two brands of
this type of flooring.

33

5. Vinyl print yard goods is similar to conventional
felt base linoleum except that the enamel for
printing the surface is made of vinyl resin.

Vinoflor, one brand, is available only in yard goods.

The tile sizes normally available are 9 by 9 inches, l2
by l2 inches and l8 by 24 inches. The calendered vinyl and roto-
gravure can be obtained in 6 foot rolls. The available gauges
of vinyl tile are one-eighth inch, three-sixteenth inch and one-
fourth inch.

Custom vinyl cork tile and lOO percent vinyl tile are
the most expensive in initial cost of the resilient floors. The
price of vinyl flooring varies with the gauge of the tile, the
percentage of vinyl and the other substance with which the vinyl
is combined. Vinyl cork and flexible vinyl rate high in initial
cost; vinyl asbestos is in the medium price range. In the opin-
ion of many operators the superlative qualities of vinyl floor-

ing justify the higher price.

Installation. Due to similarity of composition, in-
stallation of vinyl tile is practically identical to rubber.
The subfloor must be smooth, solid and dry since semi-flexible
tiles may break if placed over a rough or uneven floor. Even
though a good adhesive might hold flexible tile, the irregular-
ities in the subfloors should be sanded until smooth. For cer-
tain types of uneven subfloor a troweled underlayment such as

oxychloride may be applied.

34

Single plywood subfloor construction may flex under
pressure and cause the tiles to loosen or crack. A layer of
strong plywood nailed to the subfloor should prevent flexing.

Until recently, vinyl flooring could not be laid suc-
cessfully on concrete in contact with the ground. Several manu-
facturers of vinyl floors have now produced adhesives which
are immune to the alkali and moisture in concrete (43).

The procedure for laying vinyl and rubber tiles is
similar. A limited section of the subfloor should be coated
with adhesive at one time. An underlayment of asphalt-saturated
paper or felt requires roller leveling and a second coat of ad-
hesive before the tiles are attached. The adhesive is applied
to the subfloor with a notched trowel which has a saw-toothed
edge. The trowel, scraped edgewise, applies the adhesive in
small paralled ridges.

The preceding method can be used for either vinyl tile
or vinyl sheeting but is not used for one type of vinyl floor-
ing. This type of flexible vinyl tile is relatively thick,
grilled on the underside to resemble a waffle and can be laid
without adhesive. The many small suction cups formed by the
grill hold the tile to the subfloor. This type of flooring

may be removed and installed elsewhere (43).

Utility. The top Quality of the vinyl plastics, flexi-
ble vinyl tile, resembles rubber in appearance and is almost as

flexible and resilient (40). Flexible vinyl tile has excellent

35

wearability and is resistant to indentation, oils, grease, sol-
vents, alkalis and many acids. Compared to other resilient
floors, maintenance is economical and easy but the initial cost
is high and flooding with water may loosen the adhesive cement.
The popularity of vinyl-asbestos tile is increasing.
Although vinyl-asbestos resembles asphalt tile, it possesses
several advantages over asphalt tile. These advantages are
greater resistance to solvents, oils, greases.and alkalis.
rhuwever, vinyl-asbestos is more expensive than asphalt tile.
The general advantages of vinyl plastic tile floor

coverings are:

l. Easy and economical maintenance.
2. Availability of wide range of colors, sizes,
thicknesses and designs.
3. Excellent service life.
4. Glossy appearance.
5. High resistance to grease, alkali, solvents and
most acids.
6. Resiliency.
7. Good resistance to indentation.
8. Excellent color stability.
9. Easy repair of damaged areas.
0. Installation is not difficult.

The disadvantages of vinyl plastic floor coverings
are limited:
l. High initial price.
2. Subject to scratching from harsh abrasives.
3. Resistance to conformity to uneven subfloors.
4. Loosening of adhesive from constant flooding
with water.

Maintenance. The maintenance of vinyl tile is a con-

tFoversial subject. Some manufacturers of vinyl tile cliam

that only sweeping and clear water mopping are necessary; none
warn against use of mild detergents or floor wax (43). Those
who do not recommend detergents or waxing report that such
maintenance items are unnecessary expense since wax will not
adhere readily to the flooring. The implication is made that
vinyl floors are much more economical to maintain than the
other resilient floors. This is usually true; however, from
certain studies the consensus of opinion is that detergents

ark! waxing are necessary for proper maintenance of vinyl floor
coverings.

In l953 the Chemical Specialties Manufacturing Associa-
ti<>n employed a research laboratory to study the problem of
wasting vinyl floors (22). The technicians conducted numerous
tests, analyzed the data and presented an opinion which follows:

To summarize, our study of the effects produced by

the use of three types of floor wax on five brands

of vinyl tile disclosed the following:

i. The appearance of the tile, as judged by gloss
measurement, is greatly improved by waxing.

2. The use of wax does not significantly change
the coefficient of friction or slip proper-
ties of the tile.

3. The soiling tendency of vinyl tile may be
substantially decreased by waxing.

4. Soil removal by scrubbing is greatly facili-
tated where vinyl tile has been previously
waxed.

5. Pronounced protection against marring of
the surface results from waxing.

37

6. Some difficulty may be encountered in waxing
new tile with emulsion type waxes because of
poor wetting and spreading. However, experi-
ence indicates that after a period of use
this condition disappears.2

In these respects vinyl floorings do not differ from
other types of flooring for which decades of usage have amply
proved the need for and desirability of waxing.

In l955, Sanitary Maintenance Magazine contacted several
vinyl flooring manufacturers for recommendations on cleaning with
steel wool and waxing. The replies of thirteen manufacturing
companies showed that nine recommended waxing while four replied
that waxing was not necessary. Eight companies recommended
occasional dry buffing with steel wool.

Obviously, vinyl tile floors should be maintained in a
manner similar to aSphalt tile. The small expense of maintenance
materials may add years of life to a floor.

Nothing exists which will not in time, succumb to the
wear and tear of friction. The constant beating and scraping
of feet will eventually take toll on the vinyl surface (43).
Waxing provides a protective coating, adds to the appearance
of the floor and helps nullify the abrasive action of friction.
Wax also retains surface soil and absorbs scuffs and mars which
can often be buffed out.

Though solvent type waxes may be safely used on most

tYpes of vinyl tile, the water emulsion waxes seem most suitable

2Kimball, C. S. Waxing vinyl floors. Reprinted from
8°39 and Sanitary Chemicals. June, l953.

(43). Water emulsion waxes do not Spread easily on a new vinyl
floor but after the floor has been in use the application of

wax becomes less of a problem.

Information on vinyl floor maintenance is furnished in
a report Waxing Vinyl Floors, which may be secured from Chemical
Specialties Manufacturers Association, Inc., 50 East 4lst Street,

New York l7, New York.

39

Non-resilient Floors

Marble, tile, terrazzo and wood comprised the floors
of the Egyptian, Greek and Roman Empires and also the Middle
Ages; cement, as used today, and oxychloride for floors have
received universal acceptance more recently. These floors
all have two properties in common but in varying degrees:
all are wear resistant and lack resiliency. Their popular-
ity is due to qualities of permanence and resistance to wear

and abuse.

Concrete

Concrete construction was known to the Romans; cement
at that time was a material known as "puzzolan" cement. The
term concrete comes from the Latin word concretus, that
which is grown together.

Only since the invention of Portland Cement, first
patented in l824 by Joseph Aspdin of Leeds, England, did
concrete as a basic material of construction gain importance.
The name Portland Cement indicated the similarity of hardened
cement and stone found on the Isle of Portland. Natural elements
were first combined for use in England about l756, but large

scale manufacture did not begin until invention of the rotary

kiln in l892 (l4).

Manufacture and cost. Concrete is a compound of gravel,
broken rock or other aggregates, bound together by means of

hydraulic cement, coal tar, aSphaltum or other cementing

4O

materials. The aggregates are separated into coarse, dia-
meter of particles more than &-inch, and fine, diameter of
particles less than &-inch, aggregates. If only fine aggre-
gates are used the material is termed mortar.

When water is added to the cement and aggregates a
paste is formed due to the chemical reaction between the
cement and the water. Even the smoothest appearing concrete
floors have rough surfaces when examined microscopically and
all finished concrete floors contain a small amount of mater-
ial which can be dissolved in water.

There are two types of concrete floors, monolithic
and granolithic. The monolithic types makes good structural
concrete, but the surface does not stand up well under severe
wear. The granolithic type is differentiated from monolithic
by the following characteristics:

(l) The water-cement ratio in the mix.

(2) The method of removing the excess water once the
aggregate has been poured.

(3) Type of aggregate.
(4) The troweling operation.

(5) The curing process.

Although the initial cost may be as much as 30 percent
higher than monolithic, granolithic concrete produces a sur-
face with greater density, strength, toughness and wear re-
sistance (3i).

Concrete is the least expensive floor which can be

installed; asphalt tile is the only floor covering which is

4i

comparable in terms of low initial cost. The type of con-
crete, reinforcement, depth of wearing finish and addition
of coloring pigments determine the cost of a concrete floor.
The pigments should be resistant to alkalis and should con-
form to the specifications of the American Society for Test-
ing Materials or the Federal Government Specifications. A
wide range of color is obtainable through mineral coloring
pigments mixed with the concrete finish. From five to nine
pounds of pigment per sack of cement are required depending

upon the shade desired.

Installation. The Portland Cement Association has

listed the following requirements for installation of a con-

crete floor:

(l) Use only suitable materials.

(2) Use not more than 3% to 4 gallons of mixing
water per sack of cement when machine floating
is used and 4% to 5 gallons of water when float-
ing is done by hand. These amounts include water
used as surface moisture on the aggregates.

(3) Use mixtures and construction methods which
will not permit segregation resulting in free
water and fine material on the tap surface.

(4) Prevent early evaporation of water by keeping
the concrete wet as long as practicable.

The wearing finish of concrete floors should never be

less than l-inch thick, whether it is placed at the same
time as the structural slab or after the concrete in the

structural slab has hardened.

The chemical reactions which cause the cement to

42

harden continue indefinitely if moisture is present and tempera-
ture is favorable (33). Through this curing process the in-
ternal structure of the concrete is built up to provide

strength, resistance to wear and water-tightness. Floor
’finishes present such a large surface area that loss of mois-
ture through evaporation takes place rapidly unless preventa-
tive measures are taken. Rapid drying not only stops the .
chemical reactions, but may cause dusting and cracking of the
surface due to shrinkage taking place at a time when the con-
crete has little strength.

To prevent drying out, water for curing should be
applied to the new concrete as soon as possible without marring
the surface. The concrete should remain wet or the moisture
retained by covering the floor with waterproof paper or a mem-
brane curing compound. The longer the curing period can be
extended, the stronger, harder and more impervious will be
‘the concrete. The curing period should be at least a week
for normal cement and 3 days for high early strength cement.
Special attention should be given areas near radiators or

other sources of heat to prevent evaporation during the cur-

ing period.

Utility. Few floors or floor coverings can withstand
the abuse and heavy punishment to which concrete is often
subjected. The Eastman Kodak Company in Rochester, New York,
reported concrete floors in trucking rooms in excellent

condition after 25 years of wear; concrete floors of the

43

platforms in Grand Trunk Central Terminal in New York City
are still in use after 25 years (33).

Some of the advantages of concrete floors are:

(l) The initial cost is low.

(2) Concrete will withstand heavy usage.

(3) When properly sealed and waxed concrete is rela-
tively easy and economical to maintain.

(4) Hot water used in cleaning has little effect on
concrete.

(5) Resistance to indentation is good.

The following disadvantages should be considered:
(l) Concrete has minimal resiliency.
(2) Damaged areas cannot be easily replaced.

(3) Concrete will absorb some oils and solvents even
after sealing.

(4) Highly alkaline salts used in cleaning may dam-
age the surface.

(5) ACids exert a solvent action.

Maintenance. That concrete floors are indestructible
and immune to wear and abuse in a common fallacy. The dura-
bility of concrete floors depends upon the observance of
fundamental rules in making, placing, curing, finishing, and
maintaining the concrete. Dusting, efflorescence, or bloom-
ing may occur if these rules are violated.

Dusting occurs when a thin layer of soft, chalk mater-
ial appears on the surface. The abrasion encountered in
ordinary wear may file away the high spots on the concrete

floor. These filings form a fine dust which rises from the

44

floor and settles on everything in the room. This dusting
can usually be prevented by sealing. Dusting, crazlng and
cracking may be caUsed by inadequate curing, over-troweling
the finish, by dusting on sand or cement, or by using cement
and sand mortar for the t0p coat without coarse aggregate
(6).

Efflorescence is a dried deposit of water soluble
salts. All concrete contains a small amount of water soluble
salts which are mainly sodium sulphate, magnesium sulphate and
calcium sulphate. When the floor has contact with a source
outside the masonry material such as damp masonry walls this
moisture may dissolve the soluble salts. These salts are slowly
carried to the surface and when dried by the air the deposit
is called efflorescence or alkali ice. This deposit must be
removed with acid before sealing the floor since it makes
ian unstable base for any sealer. If there is not too much
inater pressure, the sealer may prevent evaporation and mois-
ture to the surface.

Blooming is a type of stain which appears on concrete
floors and may occur when there are too many impure salts
in the water or simply too much magnesium chloride in the
magnesite (6).; Sealing will help to prevent blooming.

After a concrete floor has cured and thoroughly dried
the surface may be improved by applying some material to
assist in hardening and binding (33). Magnesium fluosilicate,
zinc fluosilicate, sodium silicate, aluminum sulphate, zinc

sulphate, chinawood and linseed oil and various gums, resins,

45

and paraffins are used for this purpose, but will not correct
poor materials or careless workmanship. Many manufacturers

of maintenance materials produce a special application for
sealing concrete floors; some maintenance men recommend paint-
ing.

The sodium silicate treatment for concrete floors has
proved satisfactory in residence halls at Michigan State Uni-
versity. Commercial sodium silicate in a 40 percent solution
known as water glass is viscous and requires thinning before
it will penetrate concrete. A good mixture combines 3 gallons
of water with l gallon of sodium silicate. Two or three coats
are recommended and each coat should be thoroughly dry before
another is applied. Scrubbing machines will assist the penetra-
tion (33). The amount of solution required to treat a floor
will vary with the porosity of the concrete. Generally, l
gallon will provide one coat for lSO to 200 square feet of
floor surface.

Concrete floors may be painted in areas not subject
to heavy trucking or dragging. Oil paints, rubber-base paints
and synthetic resin paints are available. Three coats of
paint are advisable. The first coat should be very thin,
about equal parts of thinner and paint. Some thinner may be
used in the second coat and the third coat should be applied
as it comes from the can.

Concrete should be thoroughly cleaned and dried before
it is painted. The Portland Cement Association has recommended

that one of the two following procedures be used (33).

46

(l) After the concrete has cured for several months,
neutralize the surface with a solution of 2 to
3 pounds of zinc sulphate per gallon of water.
Allow 48 hours for this solution to react with
the concrete and to dry. Clean the surface with
water and let dry thoroughly before applying the
paint. ‘

(2) Recent laboratory tests indicated that a good

procedure was to apply a solution of 3 ounces

of zinc chloride and 5 ounces of ortho-phos-
phoric acid (85 per cent phosphoric acid) per
gallon of water to a cured floor. After this
solution has dried for 24 to 48 hours any dust

on the surface should be brushed off but the
surface should not be rewetted before applying
the paint. While laboratory tests gave excellent
results with this treatment, actual field appli-
cations at present have been limited.

After a concrete floor has been properly sealed or
sealed and painted the regular cleaning should be considered.
Since concrete is alkaline, harsh alkalis and soaps with a
high pH should not be used. Highly alkaline salts such as
trisodium phosphate or soda ash may precipitate to form
crystals which may eventually crack the concrete (2i). Syn-
thetic detergents may be preferred to soaps since they are
generally more free rinsing and some soaps may start a chem-
ical reaction with the lime in the concrete.

Maintenance people disagree on the advisability of
waxing concrete. The main complaint is slipperiness which
can be overcome with a slip-resistant wax or synthetic.
Waxing improves the appearance of concrete and makes clean-
ing faster and easier by helping to hold the soil on the
surface.

The Joint Committee on Standard Specifications for

47

Concrete and Reinforced Concrete has prepared a table on the

resistance of concrete to chemical

TABLE 2
EFFECT OF

attack.

See Table 2.

CERTAIN CHEMICALS ON CONCRETE

Substance

Effect on Concrete

 

Petroleum Oils

Coal tar distillates

Inorganic acids

Organic materials:
Acetic acid
Oxalic and dry carbonic acids
Carbonic acid in water
Lactic and tannic acids
Vegetable oils

Inorganic salts:
Sulphates of calcium, sodium,
magnesium, potassium, aluminum,
iron, Chloride of sodium,
potassium, calcium Chloride of
magnesium

Miscellaneous:
Milk
Silage juices
Sugar solution

 

None
None or very slightly
Disintegration

Slow disintegration
None

Slow attack

Slow attack

Slight attack

Active attack
None
Slight attack

Slow attack
Slow attack
Active attack

 

 

 

 

Source of data:

Encyclopedia Americana. 7:473.

 

l957.

Concrete is impervious to certain organic salts and

inorganicmateriala, slowly attacked by other substances in

these classifications and disintegrated by inorganic acids.

Hard Tile

Hard tile includes a group of clay tiles baked to a

as

stone hardness. Tile floors first became popular in EurOpean
churches during the l2th century. In the l8th century the use
of plain, undecorated, square, red tiles, known as quarry tiles,
became common in Western Europe and later in America. By l929
modern potteries all over the western world were producing

many varieties of elaborate, decorative, floor tiles for homes

and public buildings.

Manufacture and cost. Tile is manufactured from a
mixture of clays, shales, feldspar, and flint which may be
obtained locally or from various areas of the world. New
Jersey, Pennsylvania, Ohio and California produce much of
the vitrified floor tile in the United States (l6). Differ-
ing compositions of the ingredients, methods of mixing and
ways of firing account for the various types, colors and
surfaces of tile. In l927 the Department of Commerce in
Washington in conjunction with manufacturers, architects
and dealers established definite standards which cover the
manufacture, sizes and grades of white glazed tile and unglazed
ceramic mosiac.

Tile is made in many different colors with both glazed
and unglazed surfaces. The decorative possibilities of color
effects and compositions are almost unlimited. In manufacture,
the ingredients pass through grinding, mixing and refining
processes and are then formed into the desired shapes by
either the plastic or the dust pressed method. In the plas-

tic method wet materials are shaped on the moulds by hand.

49

For the dust pressed method excess water is removed and the
materials in an almost dry state are pressed by machinery to
a solid mass.

Unglazed tile, either vitreous or semi-vitreous, is
produced in one firing. The color depends upon the kind of
clay or the addition of oxides. Unglazed tile is manufactured

in the following shapes and sizes:

Square l l/l6 inches to 9 inches

Oblong l l/l6 by 7/32 inches to 9 by 4 l/2
inches

Octagonal 3 by 3 inches to 6 by 5 3/8 inches

Hexagonal 4 l/2 by 2 l/8 inches to 6 by 5 3/8
inches

Triangular l 5/32 inches to 3 inches

Glazed tile is made of the same materials and by the
same methods as unglazed tile but in two firings. The body,
called the bisque, is first formed and burned, then the
glaze is applied and the tile is fired a second time. The
glaze is a paste composed of feldspar, silica, and color-
ing metallic oxides which is spread upon the somewhat porous
bisque. The second firing at a higher temperature melts the
feldspar which fills the pores of the bisque and a continuous,
semi-transparent glaze results. By trade custom the term
glazed tile often refers to white tile and the term enamels
to the tile with a colored glaze. Glazed tile and enamels

are produced in the following shapes and sizes:

Square l/2 inch to 6 inches

Oblong 2 l/8 by l l/i6 inches to 9 by 6
inches

Hexagonal 2 5/l6 by 2 2l/32 inches to 3 by 2

l5/32 inches
Octagonal 3 inches

 

50

The most prominent floor tile is ceramic mosaic (6).
This is the familiar small tile, an inch or two on the side,
fully vitrified and usually unglazed. Ceramic is derived
from the Greek word keramas, meaning a vessel of baked clay,
and the term mosaic refers to the design in the tile. Quarry
tile is made from natural clay, is usually unglazed and is
frequently sized in 4 or 6 inch squares. Quarry tile is
commonly seen in shades of red in vestibules, hallways and
institutional kitchens where the traffic is heavy. Pavers
are unglazed tile resembling ceramic mosaic but larger in
size. Faence tiles have highly colored glazes, a rugged
artistic appearance and are often used to emphasize special
decor in a building.

Although the effort may be to produce tile of only
the best quality certain uncontrollable variations may occur.
White glazed tile is graded as to degree of perfection into
Selected, Standard, and Commercial grades. Other tile is
divided into two grades, Selected and Commercial. The Stand-
ard grade is used for general classes of work, the Selected
grade for the finest class and the Commerical grade where
sanitation and service are more important than appearance
(l7).

The initial cost of hard tile depends upon several
factors:

(l) Grade, color, and size of tile.

(2) Decorative effect and the amount of labor re-
quired for installation.

(3) Local labor rates.

5i

in most areas of this country, hard tile floors are high in
initial cost. Marble is the most expensive non-resilient
floor; tile and terrazzo of the various grades and designs

frequently overlap in a cost comparison.

Installation. Regardless of the subfloor upon which
hard tiles are to be installed, a concrete fill is necessary.
This fill may also serve as the grout between tiles and become
an integral part of the floor. The grout, which consists of
Portland Cement, hydrated lime and sand, serves both a utili-
tarian and artistic purpose. It holds the tile in place,
prevents the penetration of dirt and moisture between the
tiles and helps control expansion and contraction (43). From
an artistic standpoint the grout emphasizes the beauty of the
tile, breaking the monotony of a one color expanse and dis-
tinguishing the separation of different colors.

After installation the tile is cleaned with a diluted

acid to remove grouting from the surface.

Utility. Hard tile is particularly adapted to the
exacting demands of an institutional floor:
(l) Economical to maintain.

(2) Attractive and long wearing when properly main-
tained.

(3) Availability of large variety of colors, shapes,
sizes and decorative effects.

(4) Easy replacement of damaged areas.
(5) Not easily damaged by acids, alkalis or hot water.
(6) Not susceptible to indentation.

52

Certain disadvantages may preclude the use of tile:

(l)
(2)

(3)

(4)

(5)

High initial cost.

Susceptibility of grout to acid and alkaline
damage.

Glazed tile in kitchen areas may become greasy
and very slippery.

Tile in dishwashing rooms may crack and break
from dropped silverware and dishes.

Tile floors have little resiliency and may be
noisy from traffic.

Maintenance. Little information is available on the

maintenance of hard tile floors. Tile and grouting require

proper care to look attractive and provide long service life.

There is a slight difference in the maintenance of

glazed and unglazed tile.

Marble

(I)

(2)

Unglazed tile. Some authorities (43) recommend
seaTing and waxing unglazed tile. Any soap,
detergent or powder used in cleaning must be
one which will not disintegrate the grouting. _
In general, anything which is not recommended »:
for concrete, should not be used on hard tile.
Although many acids and alkalis will not harm
the tile they may deteriorate the grout.

Glazed tile. Synthetic detergents may prove

superior to soaps since they tend to rinse

better and leave less residue (44). Glazed
tile does not take a seal or wax readily.
Authorities differ on whether or not to wax
or seal glazed tile; many recommend waxing
but not sealing. Coarse steel wool and harsh
abrasive cleaners should never be used on
glazed tile since they may scratch the sur-
face finish. '

Ancient peoples made their finest buildings of either

53

granite or marble; the Egyptians used granite while the
Greeks and Romans found marble more suited to their needs.
The temples and arcades at Athens and Corinth and the Forum
Romanum stand as monuments to marble and to the genius of the
Greek and Roman Empires.

Marble is any limestone hard enough to take polish and
is principally calcium carbonate in crystalline form. Most
marble contains crystals of calcite or dolomite which are
white when pure; the finest white stone is called statuary
marble.

Black, gray, pink, red, green and many kinds of mottled
and banded marbles are available. The beautiful colors are
due to impurities or staining matter mixed with the calcite
or dolomite crystals; serpentine marbles are green and yellow-
ish-green silicates; fossiliferous are llmestones full of
fossil shells and on polished surfaces of such marbles the

cross sections of the shells may be seen through the rock.

Manufacture and Cost. The fabricator of marble is
mother nature, who has changed or metamorphosed limestone
through the action of heat and pressure far below the earth's
surface over a period of centuries.

Shells or irregular grains of calcium carbonate in
{crystalline form constitute ordinary limestone. In marble
‘the crystals have been ground firmly together and metamorphosis
lmas made the stone more uniform in hardness and grain, freed

it from small cavities and pores and produced a texture

 

54

sufficiently close to permit polishing, Marble may vary
in porosity from § to over l3 percent and some types are
ten times stronger than others (6).

The most famous quarries are in the Apuan Alps, an
off shoot of the Apennines, and the stone is largely worked
in the neighborhood of Carrara. Stone from these quarries
was employed in Rome for architectural purposes in the time
of Ausustine (63 B.C. - A.D. l4). The finest varieties,
adapted to the needs of the sculptor, were discovered later
and made famous by Michelangelo and Leonardo da Vinci in the
fifteenth century.

Marble is generally the most expensive floor which
can be installed. Certain grades and varieties of mosaic
tile and terrazzo may be more expensive than some of the
cheaper grades of marble. Marble is often installed when the
initial cost is not the determining factor in the selection
of a floor, but rather long life and beauty. Fancy, imported
marbles are the most expensive. Other factors which deter-
mine the cost are color, size, grade, and depth of the tile

or slab.

'lngtallation. Unlike some other floors, marble re-
quires special processes in installation. The cement bed
which receives the marble should consist of one part Port-
land Cement to not more than three to five parts of sand, mixed
quite dry for tamping and should be spread over the rough fill

(27). Grout, commonly used to separate other hard tiles,

55

providing for expansion and contraction as well as decorative
effect, is not normally used in laying marble floors since
marble has less tendency to expand or contract from changing
temperatures. The tiles are set closely together and the
edges between the tiles may be coated with a litharge and
glycerine mixture.

Marble is not adaptable for installation over wood
floors but only over a concrete or cinder fill. The Marble
Institute (27) has recommended that marble steps be laid on
metal frames imbedded in cement mortar. Plaster of Paris,
Portland Cement and non-staining white Portland Cement are
standard setting materials for all marble floors.

Marble is adapted to a high polish which is called a
"honed" finish. This highly polished finish is not slip
resistant and is also subject to abrasion. The coarser finished
marbles are known as "sand and grit" finish and "saddles". To
decrease the slip hazard, non-slip inserts and nosings are
sometimes used on stair treads and ramps.

Marble tiles are about 7/8 inch and are supplied in
standard sizes of 8 by l6 inches, l2 by l2 inches, and lO by

20 inches. Larger sizes are considered slabs rather than tiles.

Utility. The long wearing qualities and attractiveness
of marble can be substantiated by many of the buildings of the
Ronmn Empire in existence today. The utilization of marble in
a building ranges from the exterior facade to the interior walls,

column%,staircases and floors. Floors present the greatest

56

maintenance problem. For the institutional floor marble
has many distinct advantages:
(l) Availability in many attractive colors and designs.

(2) Easy to keep clean and attractive when preperly
sealed.

(3) Low maintenance cost.

(4) Excellent wear resistant qualities.
(5) Good resistance to indentation.

(6) Seldom damaged by hot water.

(7) High load limit per square inch.

Marble floors have certain disadvantages:
(l) High initial cost.
(2) Solvent action exerted by acids.

(3) Difficult removal of oil, iron and acid stains
if they have penetrated the marble.

(4) Difficult replacement of damaged areas.

Maintenance. Marble has too often been considered in-
destructible and the maintenance has consequently been neg-
lected. Thecflosely integrated surface offer little refuge
for dirt and soil and if the design is variegated it also
serves to camouflage small litter and minor stains. How-
ever, negligence will eventually become obvious in stains,
abrasion marks and even cracks.

To keep marble in good condition a regular maintenance
procedure is necessary. Strong alkaline solutions have a

tendency to penetrate the marble and, upon drying, expand

57

and break the minute cell walls, causing a surface disinte-
gration. Daily maintenance with a good neutral soap or de-
tergent is usually sufficient. To prevent stains, acids,
rust and oils from penetrating marble is much easier than to
remove them. If a floor has been neglected, it may have to
be scrubbed with a mild abrasive powder. While the Marble
Institute does not recommend or caution against seals and
waxes, many maintenance people are using them successfully.
The maintenance man who seals and waxes a marble floor should
check that the floor does not become too slippery; seals and
waxes are available which have anti-slip properities. A
well sealed, preperly waxed floor is easier to clean because
the soil is kept on the surface.

The Marble Institute (27) has published a pamphlet,
How to Keep Your Marble Lovely which contains a list of clean-
ing materials recommended. Brenn (6) has suggested that any-
one who has marble to maintain should become familiar with
A Study of Problems Rglating_to the Maintenance of Interior
Marble by D. W. Kessler, Technologic Papers of the Bureau of

Standards, No. 350.

58

Oxychloride

Oxychloride, one of the least publicized types of
flooring, is also known as magnesite, but that term is seldom
used by industry today. About 50 million square feet of
oxychlorlde flooring are installed each year; a high per-
centage of the total production is purchased by the Federal

Government.

Manufacture and cost. Oxychloride flooring is composed
principally of magnesium chloride and magnesium oxide which
react chemically to form a product having unusual cementing
properties. I

The materials for an oxychlorlde floor are supplied on
the job in two parts. One part consists of flake magnesium
chloride; the other part is a dry mix of magnesia and the re-
quired fillers, aggregates, plasticizers and color pigments.
All of these ingredients are properly proportioned and thoroughly
machine mixed by the manufacturer. The installer dissolves the
magnesium chloride in the required volume of water to yield a
solution of the proper density. The dry mix is placed in the
mortar box or machine mixer and gauged with sufficient volume
of the chloride solution to yield a workable plastic mix. Al-
most any color may be obtained since the color pigments are
simply combined with the mix.

Oxychloride flooring is available in a variety of

59

mixtures from a dense, strong, hard floor of mineral aggre-
gates to a more resilient type through the incorporation of
such fibrous aggregates as wood flour and sawdust. Terrazzo-
like floors can be produced by the addition of marble chips
to the oxychlorlde cement which replaces the Portland Cement
matrix used in the construction of conventional terrazzo
floors. The surface of these floors must be ground down.

A finished oxychlorlde floor resembles very smooth
concrete, though the color pigments may give it the appearance
of battleship linoleum; or it may have the appearance of
terrazzo if marble chips have been incorporated in the matrix.

The cost of installed oxychlorlde will depend upon the
aggregates used in the mix. In general, oxychlorlde floors
are more expensive than concrete but less expensive than
terrazzo. They may be cheaper or more expensive than some
hardwood floors depending upon the aggregate used in the

oxychlorlde and the wood floor with which they are compared.

Installation. Until the Oxychloride Cement Associa-
tion was organized in l943, no generally accepted set of
specifications was available for the laying of these floors
(8). A wide variety in quality of oxychlorlde floors re-
sulted from poorly standardized methods of installation.
Today, reputable flooring contractors follow the specifica-
tions approved by the Association.

The subfloor should be smooth and level to prevent

60

humps and irregularities on the finished floor, since rough
or uneven places are susceptible to damage through wear.

The coatings of oxychlorlde floors run from l/2-inch to 5/8-
inch in thickness.

The subfloor base for the plastic oxychlorlde mix may
be any type: concrete, stone, brick, ceramic tile, steel
and even wood. If oxychlorlde is applied over a wood sub-
floor, best results are obtained by first covering the wood
with asphalt saturated felt. A metal anchoring medium should
be nailed over the felt at 6-inch intervals (8). This metal
anchor may be a heavy wire mesh over which the plastic mix is
poured and thoroughly worked into all Openings and recesses.
When the installation mix is brought to the proper level it
is then soft-troweled and from four to six hours later given
a final hard trowelling to produce a hard, dense, smooth and
polished surface.

If the oxychlorlde coat is applied over an old concrete
floor, the entire surface of the floor must be roughened by
sandblasting, tooth-chiseling or picking. The roughening
will provide the necessary mechanical and chemical bond be-
tween the concrete subfloor and the oxychlorlde coating.

When the oxychlorlde floor is installed over a new
concrete floor the surface of the new concrete should not
be troweled in finishing. Just before the final set the

concrete should be "broomed" in one direction to produce a

6|

finish resembling tapestry brick. The new concrete subfloor
should be allowed to age for about 30 days before the oxy-
chlorlde mix is applied.

Hard subfloors such as stone or ceramic tile require
sandblasting or tooth-chiseling to roughen the surface. Since
satisfactory roughness for good bondage may be difficult to
secure, a latex or plastic base bonding medium is sometimes

used for this purpose.

Utility. Oxychloride floors are frequently installed
in hallways and lobbies. The advantages follow:

(l) Lighter and more resilient than concrete floors.

(2) High-strength to low-weight ratio.

(3) wearing hardness comparable to granite.

(4) Monolithic form of installation (one complete
slab) possible.

(5) Medium to low initial cost.

Oxychloride floors have certain disadvantages:
(l) Sealing is necessary.

(2) Maintenance is difficult.

(3) Water, alkalis and acids may cause damage.

(A) Damaged areas are not easy to repair.

Maintenance. A newly installed oxychlorlde floor
should be thoroughly cleaned after the final set but should
not be scrubbed or flooded with water for two weeks after

completion (8).

62

A good penetrating sealer should be applied after the
floor is thoroughly dry. Since an oxychloride floor is fairly
absorbent, the sealing is essential and enough sealer must
be applied to adeQUateiy fill the floor without leaving an
excess on the surface.

In cleaning an oxychloride floor a good neutral soap
or synthetic detergent is advisable; strong alkaline and acid
cleaners must be avoided. The Oxychloride Cement Association
recommends that water be left on the floor only long enough
to loosen the soil and should not be allowed to dry on the
floor. Oxychloride floors may be scrubbed with a scrubbing
machine.

The waxing of oxychloride floors is recommended by
the Association. Either solvent or water emulsion waxes may
be applied depending upon the aggregate used in the cement.
An oil-type dressing of equal parts of turpentine and china-
wood (tung) oil is sometimes used in place of wax.

In summary, these precautions should be observed in
the maintenance of oxychloride floors:

(l) Avoid acids and alkalis. Lye, sal soda, tri-
sodium phosphate or soda ash may damage the
floor.

In most cases the filler of these floors is
readily attacked by strong acids and alkalis.
The floor must be cleaned with a soap or de-
tergent which will not harm any vulnerable

filler such as cork or wood.

(2) Seal to prevent blooming. Oxychloride may
bloom if incorrectly formulated or installed.

63

(3) Use water with care. Oxychloride floors are
undesirable for high moisture installations.
If water is permitted to remain on the sur-
face the filler may rot. Moisture also attacks
and deteriorates magnesium oxychloride binder.

Terrazzo

The origin of terrazzo dates to the enterprising
Venetians of the sixteenth century who mixed odd chunks of
marble in cement to floor their terraces; hence the name
"terrazzo"-(30).

After much experimenting the Italians discovered that
if they crushed marble, mixed the small chips and poured the
marble-cement mixture into place, the surface was more uniform.
Eventually they learned that if this mixture was rubbed down
with a wet cement grout to ease the friction, the color in
the marble chips could be intensified. After pushing a rubbing
stone, known as a "gallera", back and forth across the floor
for a good many hours a beautifully colored surface was pro-
duced.

Many improvements were made in the finish of terrazzo
subsequent to its introduction in America. One of the first
was the use of metal divider strips which allowed such intri-
cate work as monograms, pictures and maps to be incorporated
into the floor. These brass and zinc alloy strips contri-
buted to strength and endurance by taking care of expansion

and contraction and by helping to prevent cracks. Rubber

 

64

and plastic materials have also provided effective divider
strips for terrazzo installations. A second development,
the electric grinding machine, made it easier to polish the
terrazzo finish, shortened the time of installation and en-
hanced color qualities. Treatment of the top surface of
terrazzo with white cement and the advent of mineral color
pigments introduced an almost limitless color selection and
provided a further refinement for terrazzo floors.

These technical improvements in the installation of
terrazzo have been instrumental in the development of one of

the truly beautiful floors of the twentieth century.

Manufacture and Cost. Terrazzo floors consist of a
mixture of 70 per cent marble chip aggregate imbedded in 30
per cent Portland cement.

The coarse aggregate is waste marble or granite chips
which have been run through a crusher and over screens for a
minimum 2-inch size grading. Although ornate patterns may
be worked into the terrazzo, many floors carry no definite
design but display an expanse of irregular, vari-colored
marble chips in close proximity to each other in the cement.

The cost of terrazzo flooring is considered medium-
high and may vary considerably in cost per square foot in-
stalled according to the grade and amount of the marble,
coloring pigments added, intricacy of design and amount of

finishing.

65

Installation. Terrazzo floors may be installed over
concrete construction by one of two methods: bond the terrazzo
to the structural slab or separate the two components.

For the first method a concrete fill of cement, sand
and crushed stone or gravel in the proportion of l:2:4 pro-
vide the underbed which should be at least i 3/4 inches below
the finished floor. Before the terrazzo is installed the
surface of the concrete should be thoroughly cleaned of all
debris and slushed with neat cement grout to ensure a good
bond.

The second procedure is advisable in buildings where
cracking is anticipated either from settlement, expansion
and contraction, or vibration, and this method requires a
total thickness of at least 3 inches above the structural
slab. The concrete slabs are covered with a thin bed of dry
sand over which a sheet of Kraft or tar paper is laid before
the underbed is installed. Consequently, the cracks origi-
nating in the structural slab terminate at the sand bed and
are less likely to appear on the finished surface.

The installation of terrazzo over wood floors requires
the following procedure:

(l) Cover the wood floor with tar paper.

(2) Place a reinforcing wire fabric lapped four
inches over this paper.

(3) Lay the concrete underbed as in method two.

(4) Pour the terrazzo topping to a minimum 2-inch
thickness.

66

The National Terrazzo and Mosaic Association (30) has

compiled detailed specifications and has stated certain pre-

cautions for the installation of terrazzo:

(I)

(2)

(3)

(4)

(5)

(6)

(7)

The terrazzo topping must be at least 5/8-inch
thick.

Composition for the terrazzo should be two parts
of marble granite to one part of Gray or White
Portland cement, mixed dry.

The finished surface should show a minimum of
70 per cent marble granite.

The metal dividing strips should be at least
i l/4-inch deep and be anchored.

The floor should be kept moist for at least
six days by sand, paper, or curing mats.

When the floors have set sufficiently they
should be machine rubbed with a #24 abrasive
followed by a #80 abrasive.

After 72 hours the grouting should be ground
off with a #80 grit. Subsequently, the terrazzo
must be cleaned, thoroughly treated and sealed.

Utility. Terrazzo has the strength and economy of

concrete and the durability of marble. For areas which re-

ceive heavy traffic such as corridors, terrazzo is one of

the best floors which can be installed. Considering service

life and maintenance, the cost is low. Terrazzo is not recom-

mended for floors under soup kettles in kitchens or for areas

which are subjected to acids or strong alkaline concentrations.

Terrazzo floors have a number of advantages:

(I)

Innumerable colors and designs.

67

(2) Long life in any area not subjected to strong
alkaline or acid.

(3) Economical in terms of maintenance cost and
service life.

(4) Smooth, easily cleaned surface.

(5) Fairly non-absorbent to soil when properly sealed.
(6) Resistant to indentation.

The disadvantages are:

(l) Medium high to high initial cost.

(2) Sealing is necessary.

(3) Damaged areas cannot be easily replaced.

(4) Strong acids or alkalis may damage terrazzo.

(5) Oil and grease spots are difficult to remove.

Maintenance. For the maintenance of terrazzo, the
National Terrazzo and Mosaic Association (30) has made a
series of recommendations:

(l) The physical characteristics of the floor must
be kept in mind in selecting the methods and
materials to maintain it. Since terrazzo is
usually 70 per cent or more marble and 30
per cent or less neat Portland Cement, the
materials and methods must be suited to mar-
ble and concrete.

(2) Suitable materials for treating and cleaning
terrazzo floors will fill the original pores
or have little effect on them. Harmful materials
(such as trisodium phosphate or soda ash) will
increase the number and enlarge the size of the
pores.

(3) Terrazzo is benefited by a penetrating sealer
which prolongs hydration of the cement to pro-
vide color density and longer life on new
terrazzo. On old terrazzo it will reduce the
penetration of water, stains and grime.

(4)

(5)

(6)

(7)

Wood

68

New terrazzo, when not given a Special treatment,
often has a dull, gray appearance. This is
caused by a deposit of efflorescent mineral salts
which are a by-product of the setting and curing
of the Portland Cement. This chemical action
continues at a decelerating rate over a period

of months, unless the terrazzo floors are sealed.

The cleansing agents used on terrazzo should not
contain strong alkalis, acids or metallic salts.
The floor must be rinsed thoroughly after each
scrubbing to remove any harmful residue.

Natural terrazzo has frictional resistance in
excess of the slip resistance minimum coefficient
of .50 established by the Underwriters Labora-
tories. Slipperiness of terrazzo is due to wax,
soap.and oil. A residual of cleaning materials
is also a common cause of slipperiness.

Low cost maintenance is an outstanding feature

of terrazzo. The Association warns against using
Cheap, unsuitable cleaning materials and especially
against soaps and scrubbing powders which contain
water soluble inorganic salts or crystalllzing
salts. These salts can crystallize out and cause
cracking and pitting of the terrazzo.

Wood floor installations in commercial establishments

and institutions are primarily hardwood. The common hard

wood floorings are oak, maple, beech, birch and pecan. Oak,

the most plentiful, constitutes the highest percentage of

wood flooring in the United States.

Oak.

Twenty varieties of oak are processed into

flooring. Except for grouping nine of them as white

oak and eleven as red oak, no attempt has been made

to classify them in commercial practice (29). In

69

quality and utility there is little difference between
the two groups. To the untrained eye the difference
between white and red oak lumber is not readily
apparent. The experienced lumber man will note,
however, that although both groups are light in color,
white oak has a brownish tinge. Red oak is character-
ized by a pink cast which usually turns reddish brown
after application of finish.

The beauty of oak is due to two important
characteristics of its cellular construction. First,
it is one of the few heavy hardwoods that are ring-
porous. The springwood of growth each year is com-
prised of larger and more prominent pores than the
summerwood and this contrast produces the attractive
figure conspicuous in plain-sawed oak. Secondly,
oak is marked by strips of cells extending radially
in the tree. Known as wood rays, these cells appear
as flaky figures when the wood is quarter-sawed.
Singular in its possession of these more or less promi-
nent wood rays, oak is the only popular flooring hard-
wood that is quarter-sawed.

‘Mggig. Next in order of p0pularity among the flooring
hardwoods is hard maple (29). The two species in

this classification, sugar maple and black maple, are
exceptionally hard and strong and have great resis-

tance to abrasion. Although lacking the striking

7O

beauty of oak, maple takes an excellent finish and is
used rather extensively where extremely heavy wear is
encountered.

Since it has no prominent springwood pores,
maple is designated as a diffuse-porous wood. The
pores are very small and evenly distributed; the wood
is close-grained, the heartwood is light reddish brown;
and sapwood is white with a slight brownish tinge.
However, the contrast in color between the hardwood
and sapwood is not as pronounced as is oak. Varying
natural colors of the wood are permitted even in the
higher grades although a special grade provides for
clean white stock.
83323. Only one species of beech is produced in this
country (29). In texture, strength, hardness, abrasive
resistance and color beech closely resembles birch.
The prominent wood rays are not sufficiently attractive
in figure to warrant production of quarter-sawed stock.
§l££fl° Of the dozen or more species of birch grown
in the United States two are utilized for flooring
(29). These are yellow birch which is abundant and
widely used and sweet birch. Like maple and beech,
birch is a diffuse-porous wood of fine, uniform tex-
ture. Hard, heavy and strong, birch possesses con-

siderable abrasive resistance. The two species vary

 

7i

only slightly; both have heartwood of reddish brown
and sapwood of much lighter color. Certain color
variations occur frequently, but these are not con-
sidered in grading. Special grades, however, are
manufactured from all red-faced stock.

‘Egggg. The hardest of all hardwoods is pecan, which
belongs to the hickory family. It is close-grained,
extremely durable, and has fine or invisible wood
rays. The heartwood is darker than that of most
woods ordinarily used for flooring (29).

Other Species. Because of scarcity and consequent
high cost, the other species occasionally used for
flooring, walnut, cherry, ash, hickory, and East
Indian teak, are relatively unimportant. Extremely
hard and durable, most of these species have grain
patterns which result in strikingly beautiful floors

and they are usually processed into parquetry.

Manufacture and Cost. Lumber processing areas in the
United States are located near the source of the raw material.
The Pacific Northwest is a leading lumber producing area;
Tennessee is another large producer of hardwood (l3).

All large mills are integrated in that they perform
both the sawing and planing operations. The sawmills are
usually built near a river or some other body of water so
that adequate storage Space is available for large log

inventories.

72

The logs are hauled from storage to the sawing floor
by means of specialized handling equipment, sawed to prOper
length, thrown onto the log deck, and from there to an ad-
justable log carriage. The sawing process is a progressive
operation and the original log may go through as many as a
dozen sawing, cutting, and trimming operations, before it
finally emerges in specified size and shape. After sawing,
the lumber is conveyed to the sorting and grading table and
from there transported to drying piles or the kiln.

Regardless of the processes used in cutting and finish-
ing, the timber must have proper seasoning and drying. This
important procedure tends to decrease shrinkage after in-
stallation, increase resistance to decay, reduce weight and
improve strength and mechanical properties (l8). The two
common methods of wood drying are air and kiln. Air drying
is cheaper but takes a great deal of time and storage space
and may result in a loss due to checking and warping of the
woods. Kiln drying, a controlled procedure which assumes
more uniform results, may employ warm moist air or super-
heated steam. The length of time varies from a few days to
several months; the longer drying period produces better
wood for floors.

Certain classes of building lumber go to lumber pro-
ducts manufacturers for further conversion to flooring.

Most hardwood flooring in the United States is manufactured

73

by specialized mills which are equipped to produce flooring
of different styles or types, with the result that a type of
hardwood flooring can be obtained to harmonize with any style
of architecture or furnishings. Broadly, these types are
classified as strip, plank, and pattern or parquet flooring.
A fourth type known as block flooring is sometimes given a
separate classification, although strictly speaking it is a
form of parquetry.
Strip flooring. As the name implies, this type con—
sists of flooring pieces cut in narrow strips of vary-
ing thicknesses. Most floors of this type are composed
of strips of uniform widths. Interesting patterns are
formed from stock selected for variations in color
or other natural irregularities; attractive designs
also may be achieved by using strips of random widths.
Most hardwood strip flooring is tongued and grooved
at the factory, so that each piece joins its neighbor
snugly when laid; square-edge strips are also avail-
able.

Strip flooring of oak, maple, beech, birch and
pecan is manufactured in a variety of sizes, ranging
in width from i inch to 3% inches and in thickness
from 5/l6 inch to 3 3/32 inches. Length of strips
in a bundle of flooring varies, but average lengths
are specified in each grade. Some strips may be as

long as l6 feet.

72+

Plank flooripg. One of the oldest types of hardwood
floors, plank flooring dates to the handcraft era

and was widely used in medieval Europe. This floor-
ing was also popular in American colonial homes and
recently the demand for it has been increasing for
homes, clubs and other buildings where an atmosphere
of rugged informality is desired. Colonial plank
flooring derived much of its charm from rough effects
and interesting irregularities which were unintentional.
This charm is retained in modern plank flooring even
though the product is now precision made.

Plank floors are random width pieces tongued and
grooved, with square or matched ends. Frequently, the
edges of planks are beveled to reproduce the effect
of the large cracks which characterized early hand-
hewn plank floors. The wood pegs by which the old
plank floors were fastened are simulated by means of
wood plugs glued to holes on top of the countersunk
screws which actually fasten the planks to the sub-
floor.

Solid planks generally are processed in 25/32-
inch thickness for tongue and groove flooring and
5/l6-inch thickness for square edge flooring. Widths
range from 3 to 9 inches in multiples of l. Minimum
length for certain types is 2 feet, for others 3

feet.

75

Pattern or Parquet Flooring. Pattern floors, known

as parquet and design floors, appeared as early as

the l4th century in Europe and represent the most
elaborate and expensive type of hardwood flooring.
Early pattern floors presented bizarre effects which
would be incompatible with present architectural styles.
Today parquetry assumes geometric patterns such as
squares, rectangles and herringbone in almost infinite
variety. Literally hundreds of designs are available
which may feature variations of species or of shades
of the same species. Most parquet flooring is oak,
although it also is produced in maple, beech, walnut
mahogany, East Indian teak and ebonized wood. The
latter consists of dyed white maple or holly.

Parquetry is manufactured in short lengths of
individual pieces. Each piece must be cut to exact
dimensions to match perfectly the dimensions of an-
other piece, or multiples thereof. Customarily
tongued and grooved and end-matched, the pieces are
laid separately, either by nailing or setting in
mastic.

Parquetry is manufactured principally in 25/32-
inch thickness. Most common face width for each piece
is 2 l/4 inches, but widths of l l/2, 2 and 3 inches
can be obtained by special order. Standard lengths

are in multiples of face width.

76

Block flooring. Block flooring, a form of parquetry,
differs from conventional parQuetry in that the pieces
are assembled into square or rectangular blocks at the
factory. They are held together by various means on
the back, sides or ends. These prefabricated blocks
are laid as units, either in mastic or by nailing.
Prefabricated blocks are made in thicknesses of
l/2 inch, 25/32 inch and 33/32 inches. Customary
strip widths are l l/2, 2,2 1/4, 3 l/4 and 4 inches.
All thicknesses are not produced in every width.
Dimensions for the completed blocks, of course, are
in multiples of the strip widths.
Many complex and inter-related factors affect the in-
stalled cost of a wood floor.
(l) The grade, pattern, size, and type of wood.

(2) The area of the country in which the floor is
installed.

(3) Local labor rates.

(4) Subfioor on which the wood is laid.

In general, hardwood floors rank relatively low in
initial cost of non-resilient floors. Oak is the cheapest
followed by birch, beech, and maple. There is, however,
overlapping in price between various grades of the different

varieties of wood.

Installation. Building experts are unanimous in

77

agreeing that in conventional joist construction sound sub-
flooring beneath the finish flooring is essential. Ordinarily
nailed directly to floor joists, subfloors are so necessary

to good construction that most modern building codes specify
them. Their ommission usually is poor economy, even though
the finish floor is of strong, durable wood.

Subfiooring serves several important purposes. It
lends bracing strength to the building and provides a solid
base for the finish floor, practically eliminating the possi-
bility of floor sag and squeaks. By acting as a barrier to
cold and dampness, subflooring helps keep the building warmer
and drier in winter and provides a safe surface during
erection of the building.

If strip flooring is to be used, flooring should con-
sist of good quality wood boards about i inch thick and not
more than 6 inches wide. Wider boards are subject to ex-
cessive expansion and contraction. The boards should be
Spaced about one-fourth inch apart, and face-nailed solidly
at every bearing point with two lO-penny nails. Inadequate
nailing may result in squeaky floors. In order to provide
maximum support, all butt joints of the boards should rest
on joists.

Square edge boards are preferred to tongued and grooved
boards because the snug joining effected by the latter is un-
desirable in subflooring. Boards should be kiln dried or
thoroughly air dried. The use of green subfloor boards fre-

quently causes squeaks.

7s

The subflooring should be laid diagonally. This
arrangement not only adds bracing strength to the building,
but permits the finish strip flooring to be laid in any
direction. Should the building be of two or more stories,
the subfloor boards should run in opposite diagonal direc-
tions on alternate floors.

Before installation of the finish flooring is to be—
gin, the subfloors should be examined carefully and any de-
fects corrected. Raised nails, for instance, should be
driven down and loose or warped boards replaced. The sub-
floors should be swept thoroughly or scraped if necessary
to remove all plaster, mortar, or other foreign materials.
These precautions must be observed if the finish flooring is
to be laid properly.

The last operation before actual installation of the
wood finish flooring should be the application of a good
quality aSphalt coated building paper over the subflooring.
This will protect the finish floor and the interior of the
building from dust, cold and moisture which might seep through
the floor seams. Strip flooring presents the most attractive
appearance when laid lengthwise of the longest dimension.

Adequate nailing is absolutely essential in the finish
floor as well as the subfloor. The baseboard is installed
with the lower edge slightly above the finish floor. Shoe
moulding should be nailed to the baseboard after the entire

floor has been laid.

79

The National Oak Flooring Manufacturers' Association

(29) and the Maple Flooring Manufacturers' Association (26)

list directives for the installation of a wood floor.

(I)

(2)

(3)

(4)

(5)

The building in which wood flooring is to be
laid should be heated for l0 days to at least
70°F. The flooring should be loosely piled

in the building for several days to acclimate
it to the moisture conditions in the building.

Provision for an eXpansion joint (the width
depending on size of floor area) is a safe-
guard against buckling. Dry flooring laid
in a damp building will swell and may cause
cupping or buckling.

Do not lay flooring until plastering and ce-
ment work are thoroughly dried and woodwork
and trim are installed. Ail plumbing, eles-
triCal wiring, plastering and painting should
be completed before the finish floor is begun.
The laying and finishing of hardwood floors
should be the last Operation in building
construction.

Do not close the windows; Opening a window
at the top aids in driving out moisture
through air circulation.

DO not under any circumstances lay the flooring
tight against studding or walls.

More detailed information on the installation of wood

floors can be obtained from these Associations.

inlity. A prOperly installed and maintained hard-

wood floor has well known advantages:

(l)

(2)

Structural strength. Certain species have been
known to support weights Of 5,000 pounds per
square inch.

Qurability. Properly installed and maintained
hardwood should last many years in certain
areas of a building.

(3)

(4)

(5)

(6)

80

Comfort. All of the hardwoods possess consider-

able insulating value. They are easier to walk

or work on than other non-resilient floors.

Attractiveness. The natural variations in the
wood form an attractive flooring design.

Capacity for bein restored. Good hardwood
fFOors can usuaTTy be sandEd and refinished to
Obtain a new surface.

Availability. Most of the hardwoods are available
ifiia variety of sizes and sahpes. Oak grows in
greater abundance than any other hardwood, con-
sequently, it is produced in greatest volume,

and normally is readily available.

Certain disadvantages of wood for institutional floors

are also known:

(I)
(2)
(3)
(4)

(6)

(7)

Installation requires an expert.
Wood floors require sanding and sealing.
Highly alkaline cleaners can damage the wood.

Excessive use of water on wood floors can cause
swelling, warping and buckling.

Open grain woods such as oak require a filler

'in addition to sanding, sealing and waxing.

The maintenance of wood floors in areas such
as dining rooms and kitchens may be expensive.

Well sealed wood floors are not entirely resistant
to solvents, greases and acids.

Maintenance. The ideal hardwood floor finish should

be attractive, durable, easy to maintain and should have the

capacity for being retouched without revealing a patched

appearance.

The finish applied to the flooring should be

transparent to accentuate the natural beauty of the wood.

Ql

V

The three principal types of finishes are: floor seal,
varnish and shellac. Lacquer is applied occasionally but the
most popular finish for institutions is the floor seal. Two
types Of floor sealers are adaptable for hardwood floors:
the penetrating and the surface coatings.

Requirements of a good floor finish:

(l) The finish must have penetrating qualities that

become an integral part of the wood itself, so
that after application it will only wear away

as the wood wears away.

(2) The finish must seal the pores in order to keep
out dirt and resist soil stains.

(3) The finish with its penetrating qualities must
not darken the wood, but must give the floor an
attractive, satin-like sheen, showing the vary-
ing natural color Of the wood.

(4) The finish must reflect light to improve illumina-
tion.

(5) The finish should be non-slippery.

(6) The finish must not mar, scratch or flake.

(7) The finiSh must be of such quality that even
retouching Of worn Spots can be accomplished
without complete refinishing, and, with the
resulting treatment, show a uniform appearance.

(8) The finish (sealer) after application, must
insure economy in maintenance in order to
eliminate constant resanding and complete re-
finishing.

Directions for applying floor seal, vary with specific
recommendations of manufacturers. In general, the seal is
first applied across the grain, then smoothed in the direc-
tion Of the grain by a wide brush, squeegee or wool appli-

cator. After a period Of l5 minutes to 2 hours, depending

82

on the directive of the manufacturer, the excess seal should
be wiped off with clean cloths or a rubber squeegee. For
best results the floor is then buffed with #2 steel wool.
Two coats of seal are recommended with buffing after each
coat.

Both the Maple and Oak Manufacturers Associations
recommend waxing after the sealer has dried thoroughly with
either paste or liquid wax.

Any good soap which is not too highly alkaline can
be used to clean wood floors. However, continuous scrubbing
or even wet mopping may cause the boards to warp or cup.

In general, highly alkaline cleaners and excess amounts of
water should be avoided in the maintenance Of wood floors.
Vacuuming, dust mOpping and sweeping will help to prolong

floor life.

83

Comparison of Resilient Floor Coverings
and Non-Resilient Floors

The preceding discussion has pointed out the important
characteristics of the various floors and floor coverings.
Tables 3, 4, 5, 6, 7 and 8 summarize certain advantages and
disadvantages of particular significance to management.

Tables 3 and 4 illustrate the point that each floor
has both favorable and unfavorable service qualities. As
an example, resilient floor coverings which are low in cost
are generally most difficult to maintain. The high cost
non-resilient floors such as marble and hard tile rate ex-

cellent for wearabillty and ease Of maintenance.

TABLE 3
COMPARISON OF RESILIENT FLOOR OOVERINGS

 
  

 
 

 
 

 
 

 

 

- M -. .- _.-.__.-. _ "a“

 
   
 

 

  
 

”-mw—n- .. .--——— —..————~-—-—-.—-— ..———v—-

 

“*1“

 

m—s - -u-

 

Floor initial Wear- Resistance to :0le Ease of Comfort

Covering Cost ability Indentation Stability Maintenance

Asphalt Low Poor Poor Fair Poor Fair

tile

Cork High Fair Poor Fair Poor Excellent

Linoleum Medium 2 Good Fair to Good Fair to Good

good gOOd

RUbber High Good Good Good Good Excellent

Vinyl High to Excellent Excellent Excellent Excellent Good to
very high , excel lent

Vinyl Medium Fair Fair Fair Fair Fair

Asbestos

W

Source Of data: Compiled by the author.

84
TABLE 4
COMPARISON OF NON-RESILIENT FLOORS

 
 

   

—~—_.,—.

Floor

_ _.. ._... . ._ __.__.. —— ——.—————»-—

r H Rsinstace Color Ease Of Comfort »

       

.- Iitial

 

Covering Cost abi lit y Indentation Stability Maintenance

Omcrete Low Good Excel lent Fair Good Poor

Oxychlor- Medium Fair Excel lent Good Fair Poor

ide

Marble Very Excellmt Excel lent Excellent Excellent Poor
high ‘

Terrazzo High Excellent Excel lent Excellent Excellent Poor

Hard Tile High to Excellent Excel lent Excellent Excellent Poor
\mryhgh

Wood Low to Fair to Good Good Fair to Fair
Medium good Poor

m

Source of data: Compiled by the author.

Table 5 indicates the maximum safe load limit for the
resilient floor coverings. Asphalt tile, which is low in price,
also has a low load limit. Rubber and vinyl which are high in
cost have a high load limit.

TABLE 5
MAXIMUM SAFE LIMIT FOR RESILIENT FLOOR COVERINGS

 

 

 

Floor Covering Load Limit In Pounds Per Square Inch
Asphalt tile 25
Vinyl-asbestos 25
Cork tile 40
Linoleum 75
Rubber 200
Vinyl 200

 

 

_.__ A V r J—
l

 

Source of data: Earl Brenn's Floor Maintenance Manual,
page XV-2.

85

Table 6 shows the resistance to indentation of various
floors and floor coverings. The hard floors such as hard tile
or marble are virtually immune to indentation. Softer floors,

cork or asphalt tile, are more susceptible to damage.

TABLE 6

RESISTANCE T0 INDENTATION OF SELECTED RESILIENT FLOOR
COVERINGS AND NON-RESILIENT FLOORS

 

Material Indentation
VitreOus tile 0.0
Neat Portland Cement 0.0
Marble 0.0
Maple Wood 0.0
Oxychloride 0.0
Rubber 4.0
Linoleum l3.6
Cork tile 26.7
‘Asphalt tile 61.9

 

 

Source of data: Earl Brenn's Floor Maintenance Manual,
page XV-3.
Tables 7 and 8 show the relative costs Of floor cover-
ings and floors in the Lansing, Michigan area as of March,
l959. Actual dollar cost may fluctuate but the relative

ratings remain fairly constant.

86

TABLE 7
COMPARATIVE COSTS OF RESILIENT FLOOR COVERINGS

Floor Covering Relative Cost

 

Asphalt tile l

 

 

 

 

 

 

Vinyipasbestos l.5 - 2

Linoleum l.5 - 2

Rubber Bel - “

Cork 3-I - 6

Vinyl 2.5 - '0
TABLE 8

COMPARATIVE COSTS OF NON-RESILIENT FLOORS

 

 

 

Floor Covering Relative Cost
Concrete l

Wood l.l - l.5
Oxychloride l.2 - 4.5
Terrazzo 3 - IO
Hard tile 5 - l5
Marble l5 - 25

Source of data: Compiled by the author.

87

This manual has attempted to show that there is no
simple answer to the overall flooring problem. The discussion
and tables in this report should be helpful in the selection
Of flooring for an institution.

It has been pointed out that the purchase Of a floor
or floor covering on initial price only is not economically
sound. Floors that are low in cost may be uncomfortable to
work on or may require expensive maintenance to prolong their
life. Even the high priced floors such as marble or quarry
tile have their disadvantages. All of the pros and cons of
each type Of floor and floor covering should be considered

before the final selection is made.

l2.

'3.

88

LITERATURE CITED

American HOSpital Association. Manual Of hospital house-
keeping. Pub. M l6-52. Chicago, The Association. i952.

American Hotel Association. Floor maintenance manual.
New York, The Association. l950.

ASphalt Tile Institute. Maintenance of aSphalt tile
floors. A.I.A. File NO. 23-6 (NN) New York, The
Institute. l948.

ASphalt tile today. Better Maintenance. 4:8-35. June,
I957.

Barron, J. L. and Burner, A. J. Building and equipment
sanitation and maintenance. New York, Association of
American Soap and Glycerine Producers, Inc. i956.

Brenn, Earl. Floor maintenance manual. Huntington,
Indiana, The Huntington Co. l955.

Brown, W. T. Custodian engineer. Los Angeles. Los Angeles
Trade-Technical Junior College. l954.

Characteristics and care Of oxychloride flooring. Sanitary
Maintenance. l2:29-80. October, l954.

Chemical Specialties Manufacturers Association. Scientific
Committee, Waxes and Floor Finishes Division. Floors
and floor coatings. New York, The Association. ,l956.

Choosing wood flooring. Popular Science. l73:l80-l84.
November, l958.

Clarke Sanding Machine Company. Your floors and how to
maintain them. Muskegon, Michigan, The Clarke CO. l957.

Cloyes, P. W. Match flooring materials to service condi-
tions. Better Building Maintenance. 5:l6-22.
November, l958.

Colliers Encyclopedia. Lumber industry. l2z594-597. New
York, P. F. Collier & Son Corp. l955.

Encyclopedia Americana. Concrete. 7:465-474. New York,
Americana Corp. I957.

 

l8.

l9.

20.

22.

23.

24.

25.

27.

28.

89

Encyclopedia Americana. Pottery. 25:453-460. New York,
Americana Corp. l957.

Encycl0paedia Britannica. Tile. 22:2l3—2l5. London,
Encyclopaedia Britannica Inc. I956.

Gay, C. M. and Parker, H. P. Materials and methods of
architecture. New York, John Wiley & Sons, Inc. l948.

Holder, M. E. A study of floors on a college campus.
Unpublished M. S. thesis. East Lansing, Michigan.
Michigan State University Library. l949.

How to choose a floor covering. Institutions. 4l:70-7i.
September, l957.

JOhnson, B. S. Resilient floor maintenance. Better
Building Maintenance. 5:3l-36. December, l955.

Kessler, D. W. Terrazzo as affected by cleaning materials.
Journal of the American Concrete Institure. 20:33-40.
September, l948.

Kimball, C. S. Waxing vinyl floors. Reprinted from Soap
and Sanitary Chemicals. June, l953.

Lanzilotti, R. F. Production and marketing of asphalt
tile. Pullman, Washington, State College of Washing-
ton Press. l955.

Linoleum floor care. Better Maintenance. 4:28-34. March,

l957.

Maglio, M. M, Floor cleaner evaluation. The Journal Of
the American Oil Chemists Society. 28:267-27l. June,
l95i. .

Maple Flooring Manufacturers Association. Finishing
northern hard maple the MFMA way. Form No. 3l580.
Chicago, The Association. I958.

Marble Institute of America, Inc. How to keep your
marble lovely. Mount Vernon, New York, The Institute.
I958.

Miller, S. J. What are cleaning materials? How do they
work? Journal Of the American Dietetic Association.
27:24-27. January, l95i.

29.

30.

3i.

32.

33.

34.

35.

36.

37.

38.

39.

40.

4|.

42.

43.

44.

90

National Oak Flooring Manufacturers Association, Inc.
The hardwood flooring handbook. Memphis, Tennessee,
The Association. l958.

National Terrazzo and Mosaic Association, Inc. Terrazzo
for fine floors. Washington, D. C., The Association.

l957.

Perry, W. C. Good concrete floors. Better- Building
Maintenance. 5:8-25. September, l958.

Polinow, F. J. Jr. pH explained for the layman. Re-
printed from Sanitary Maintenance. September, l952.

Portland Cement Association. Cement floor finishes.
Chicago, The Association. l957.

Regarding rubber tile. Sanitary Maintenance. l4:56-93.
May, l956.

Review of asphalt tile. Sanitary Maintenance. l4:26-7l.
March, l956.

Rubber Manufacturers Association. Approved maintenance
methods for rubber floors. A.I.A. File NO. 23-C.
New York, The Association. l957.

Selling linoleum maintenance. Sanitary Maintenance.
l4:76-l43. April, l956.

Viles, N. E. The custodian at work. Lincoln, Nebraska,
The University Publishing Co. l94l.

Vinyl floor maintenance. Sanitary Maintenance. l3:75-l70.
March, l955.

Which resilient flooring? Better Building Maintenance.
4:l4-2l. November, l957.

White, W. H. Soap dope. Sanitary Maintenance. l3:59-ll4.
March, i955.

World Book Encyclopedia. Marble. ll:4795-4796. Chicago,
Field Enterprises Educational Corp. l957.

Wright, Jonathan. Floor maintenance manual. Milwaukee,
Wisconsin, Trade Press Publishing Co. l956.

. Nature and maintenance of hard tile floors.
Sanitary Maintenance. l2:2l-7l. November, l954.

9i
45. Wright, Jonathan. Some facts about cork tile. Sanitary
Maintenance. l2:2l-66. August, l954.

46. . What tO do about slippery floors. Sanitary
a ntenance. l2:32-37. July, (954.

47. . What you should know about marble floors.
Sanitary Maintenance. l2:24e68. June. l954.

APPENDIX

TRADE ASSOCIATIONS FOR THE FLOORING INDUSTRY

American Concrete Institute
l8263 W. McNichols Road
Detroit l9, Michigan

Asphalt Tile Institute
lOl Park Avenue
New York l7, New York

Assoc. of American Soap and
Glycerine Producers

295 Madison Avenue

New York i7, New York

Chemical Specialties
Mfgrs. Association

50 East 4lst Street

New York i7, New York

Maple Flooring Manufacturing
Association

35 East Wacker Drive

Chicago I, Illinois

National Assoc. of Marble
Dealers

2l9 E. Island Avenue

Minneapolis, Minnesota

National Oak Flooring Assoc.
8l4 Sterick Bldg.
Memphis 3, Tennessee

National Terrazzo and Mosaic Assoc.
7li-l4th Street, N. W.
Washington, D. C.

Oxychloride Cement Association,Inc.
'832 "M" Street, N. W.
Washington, D. C.

Portland Cement Association
33 West Grand Avenue
Chicago l0, Illinois

The Marble Institute Of America
32 South 5th Avenue
Mt. Vernon, New York

The Rubber Manufacturers
Association

444 Madison Avenue

New York, New York

Tile Council of America
l0 E. 40th Street
New York l6, New York

Tile Manufacturers Association
50 East 42nd Street
New York l7, New York

 

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