------Stone Maintenance
DEFINITIONS
1. Marble - In the current language, is any stone used for decorative
purposes and takes a polish. The Greek word for marmores
means glistening. More technically, marble is a limestone that
has crystallized due to a metamorphical process over a very long
period of time, ranging from 7 to 120 million years.
The Marble Institute of America has assigned group classifications
for soundness and working qualities. We repeat, working qualities
only. "D" marbles can be and are generally more decorative and
more expensive than "A" marbles.
Group A - Sound marbles with uniform, favorable working
qualities.
Group B - Marbles similar in character to the proceeding group,
but working qualities somewhat less favorable; occasional natural
faults, limited amount of waxing and sticking necessary.
Group C - Marbles of uncertain variations in working qualities,
somewhat less favorable working qualities; geological flaws, voids,
veins, and lines of separation.
2. Agglomerate (Marble) - Marble chips bound with resin containing marble
dust generally composed of 90-95 marble and having a brecciated
appearance.
3. Granite - Derived from the Italian word, "Granite" meaning "grained."
It is a very hard, crystalline, igneous or metamorphic rock primarily composed
of dark minerals. Mineral grains are visible to the naked eye.
This material is frequently characterized as more resistant to damage (e.g.
staining, etching, etc.), harder, and more uniform than marble, travertine,
onyx, limestone or slate.
4. Travertine - Ivory to golden brown colored limestone formed over a period of
about 600,000 years by precipitation in hot mineral springs. It comes out of
the ground "relatively" soft compared to marble, but hardens with age and
exposure. It has a sponge-like texture with up to 1/2" holes. These cavities
are frequently filled with a matching Portland cement.
DEFINITIONS (Continued)
5. Onyx - An agate-like stone formed by precipitation in cold mineral springs.
It is often translucent with a layered look.
6. Stones that do not take a polish:
A. Slate - A fine-grained metamorphic rock derived from clays and more
often, shales. Slate has a cleavage that permits it to be readily split
into thin, smooth sheets.
B. Limestones - A sedimentary rock which, while relatively soft,
weathers well. It has a very tight-grained appearance.
WALKER/ZANGER MARBLE CARE
INTRODUCTION: Marble, Granite, Travertine, Onyx, and Slate are extremely durable, long-
lasting stones. Although they require little maintenance, as with other fine products, periodic
upkeep is recommended. Wholesales and importers of the world's finest natural stones
recommends the following regimen to keep all of your natural stone beautiful.
STAIN PREVENTION: Most stones are porous and readily absorb liquids and moisture.
Materials like limestone and sandstone are extremely absorbent, whereas granites and
serpentines (green marbles) are denser, but will still absorb liquids that are allowed to remain
in contact with them for extended periods of time. In areas where stains are likely to develop,
protective measures should be taken.
The use of a sealer will help prevent staining in most situations. WaIker/Zanger recommends
Miraseal 511 Impregnator, which is specifically, formulated for sealing stone surfaces. It acts
by actually filling the small pores in the surface of the stone, and can easily be applied to
polished, honed, rough, or sanded surfaces.
Even a sealed surface can be stained if left in contact with a sealing agent for long periods of
time. Therefore, all spills should be wiped up as soon as possible, and coasters or napkins
should be used when serving food or drinks on a stone bar, table, or countertop. Soft drinks,
coffee, tea, and fruit juices contain mild acids and can etch the polished surface of a stone
and stain quite rapidly. These should be cleaned-off immediately with a mile soap and warm
water. Remember, do not use any abrasive cleaners.
REGULAR CLEANING: In order to prevent staining or dirt build-up, regular cleaning is
recommended. Stones should be rinsed weekly with warm water and a non-abrasive, clear.
non-acidic soap. Periodic cleaning with Miraclean #1 will help keep your marble dirt free and
allow the natural beauty to shine through.
Miraclean #1 is specifically designed for use on natural stones and will not stain or scratch, it
is the perfect product for removing surface dirt, grime, and film.
For polished marble and granite we also recommend periodic application of Miraseal Stone
Polish. Miraseal Stone Polish is not silicon bases, so it will not yellow or discolor natural
stone. It will enhance the beautiful luster of the marble and afford an extra measure of
protection.
STAIN REMOVAL: If stains do occur, or if you are restoring an ancient piece of stone, a
poultice or restorer may be required. Whereas a cleaner will wash off surface dirt, a poultice
will actually draw out deep seated dirt and stains from the stone's pores. A professional
marble shop should be contacted for this type of work. Poultice in most cases will remove the
polish.
WALKER/ZANGER MARBLE CARE (Continued)
TIPS ON PROBLEM AREAS: Showers get a lot of soap residue and lime buildup. These do
not affect the marble but pose a cleaning problem. Marble cannot be cleaned with the tile
cleaner because of etching, so to keep it clean, it must be wiped out with a towel after every
use. With less frequent cleaning where buildup has occurred, cleaning has to be done with
razor blades and steel wool. A way to still get the effect of the marble, eliminate the cleaning
problem, and also save money, is to make just the jamb, curb, and outside trip of marble and
use ceramic tile on the inside walls. With the shower door closed you see only the marble
trim and the door when viewed from the outside.
Marble bar tops, because of etching from alcohol, citric, and other acids will lose their gloss
quite rapidly. At first the dull etched places show up vividly because of the contrasting gloss,
but with further use, the whole top will assume a more even, but dull finish. In spite of this, it
will still look good. Granite will, however, stand up to most mild acids without etching.
"MARBLE CARE'
By Robert Hund, Managing Director,
Marble Institute of America
Why has there been so much interest on the topic of interior marble cleaning and
maintenance? Marble has been recognized as a popular building material for centuries for its
beauty and structural qualities.
The reason for today's interest is due to the growing popularity of marble within the last eight
years or so. The Marble Institute of America estimates the installed value of marble used in
1983 at about three-quarters of a billion dollars! Building owners, designers and architects
have apparently rediscovered the elegance of marble for enhancing the environment, and
have been specifying it more and more.
Marble doesn't wear out, but like any other" material, it does get dirty, and has to be
maintained. Marble is ageless, and can withstand abuse as time passes, but it must be
conditioned. Commercially, marble is defined as any stone capable of taking a polish (except
for the eruptive stones, such as the granites.)
As a metamorphised, recrystallized limestone, the formation of "true" marble is a result of
geological evolution. Intense heat and pressures give it the hardness and durability for long-
term wear. The different colors in marble probably come from water containing minerals or
dissolved vegetation which seeped through the stone and into minute fissures and cracks
when its bed was shifted, thereby producing veining or distinctive overall coloration. That's
why the travertines, onyxs, serpentines and some of the dolomitic limestone -
unmetamorphised stones - are identified as "marble."
WHAT CAUSES MAINTENANCE PROBLEMS WITH MARBLE?
Since marble has so many inherent qualities which endow its performance as a superior
finishing material, what causes all the confusion about proper maintenance?
The most frequent question housekeepers ask this office is "how can we prevent traffic
patterns on polished marble floors?" The Marble Institute has always discouraged the use of
polished marble for commercial floor applications for that very reason. Instead, a honed finish
should have been specified. (A honed finish will develop through wear and the polishing of
shoe leather the same pleasing patina seen in ageless marble installations.)
But this gem of knowledge, after the fact, provides little assistance or comfort to those
involved in housekeeping operations who have the problem of obvious traffic patterns.
Some knowledge of how marble is polished may be helpful. Marble comes from the earth in
the form of blocks weighing 15-16 tons. It is then cut into slabs. These are placed on a
polishing table.
WHAT CAUSES MAINTENANCE PROBLEMS WITH MARBLE? (Continued)
Although many city marble shops still use hand-operated rotary polishing machines, almost
every factory now has computer-controlled automatic bridge polishers, with several rotary
polishing heads. "Bricks' containing successively finer abrasives work back and forth over the
slab until a honed finish is achieved.
The final, high gloss shine is actually a chemical reaction produced by intense heat combined
with the application of tin oxide putty or oxalic acid in the "bricks", or felt finishing discs.
Once the shop-applied finish is worn off, it is rather difficult to put it back on. But it can be
done using a floor scrubber with a medium-to-soft brush and damp tin oxide or oxalic acid.
Since only small areas should be worked, the process is time-consuming, but it is effective.
Marble walls can be re-polished in the same manner, either with using lighter-weight polishing
machines, or by hand. It is hard work and best left to be done by professionals. The Marble
Institute has members who specialize in maintenance and renovation. Based on the growing
need of professional marble care, we expect many more service companies to include this
specialty.
HOW CAN YOU PREVENT MARBLE MAINTENANCE PROBLEMS
The best prevention is regular cleaning. Dry mop floors frequently to sweep up dirt and grit.
Wash them regularly with neutral soap and soft water. Then rinse and buff.
Wipe down walls. Wash them with neutral soap. rinse and shine them. Wipe off countertops
as frequently as possible. Marble is an alkaline substance, and most food and beverages
contain acids, which chemically attack marble surfaces.
In other words, treat marble in the same manner you would care for fine furniture. The values
are the same. Marble lasts longer with proper care though.
Avoid cleansers that contain grit or are highly alkaline in composition. Griy scratches
polished marble. Also, particles of asphalt or tar tracked on floors contain oil, and highly
alkaline cleaning media are apt to dissolve or emulsify the oily matter and carry it into the
marble causing stains which are hard to remove.
Most importantly, make certain that no matter what cleaning product is applied, surfaces must
always be thoroughly rinsed clean. Soap film left on surfaces becomes slippery. Salts in
alkaline cleaners, if not washed off, penetrate and form crystals which grow in size and exert
great pressure. In some cases, the effect becomes apparent by surface spalling, while in
others, visible injury may not show for some time. Even the strongest and most dense
marbles cannot resist this action indefinitely.
HOW CAN YOU PREVENT MARBLE MAINTENANCE PROBLEMS (Continued)
Avoid the use of cleaning products that have distinctive colors. These used over a period of
time tend to impart their own character into that of the marble.
SHOULD MARBLE BE SEALED?
Within our organization, MIA, there is still no general agreement. While the traditionalists
maintain that regular cleaning will preserve the beauty of the stone, they allow that some
"problem" areas around urinals, for example, should be protected. Although the Marble
Institute makes no recommendation for or against application or proprietary products, if a
sealer is used, it should be one that allows the stone to "breathe."
MARBLE POLISHES AND TREATMENTS
There are many ready-made chemical preparations for marble treatment and polishing. We
recommend the prudent building maintenance executive test before making large scale
purchases and applications. Marbles, as unique creations of nature, have differing
characteristics, and a cleaning method that works fine on one marble installation may be
rendered less effective on another.
The following information is from a chapter in the Marble Institute of America's Design Manual.
It outlines the various types of marble, their uses, their normal maintenance problems:
Prevention and Cures.
MAINTENANCE OF POLISHED INTERIOR MARBLE
Polished marble has a glossy surface that reflects light and emphasizes the color and marking
of the marble. It traditionally appears as a wall veneer, but it is also seen in the form of
furniture tops, desks, tables, and other designer pieces.
Normal maintenance involves only periodic washing with clean water and mildly alkaline
cleaners "Soapless" cleaners are recommended because they minimize streaking and
filming Marble surfaces should first be wetted with hot water. Then, using the cleaner
solution (following manufacturer instructions), wash in small overlapping sweeps (from bottom
up, if the surface is vertical).
Rinse thoroughly to remove all traces of soap or cleaner solution. Change the water in the
rinse bucket frequently. Dry with a soft cloth or cotton flannel, and allow to thoroughly air dry
before applying any top dressings. Chamois skin may be used for drying.
When marble is thoroughly dry. a top dressing may be applied. There are quite a few
available which help prevent staining and water spotting. Do not use any oil-based dressings
or colored waxes.
HONED INTERIOR MARBLE CARE
A honed finish is a satin surface with relatively little light reflection. It is specified for floors,
thresholds and other locations where the presence of water might make a polished finish
slippery, or where heavy traffic would wear off the polished finish.
As a rule, honed finishes are more susceptible to soiling than polished finishes, because a
honed surface is slightly more porous and absorptive than a polished finish. However, the
honed finish is easier to restore because it will sustain harsher cleaning efforts.
Normal maintenance of honed finishes involves as-needed washings with clean water and
mildly abrasive cleaners, which retain a pumice-type finish, while the cleaners remove soils.
There are thick liquid cleaners and chlorine-bleach type scouring powders commercially
available.
The marble should be wetted with clean hot water, then using a mildly abrasive alkaline
cleaner and a stiff bristle brush, wash in overlapping, twirling strokes. Suds can be left to
stand for several minutes to permit the bleaching agents to work on stains and dirt. Rinse
thoroughly and dry with cotton, cotton flannel, burlap or chamois skin. Wipe well to avoid
streaking.
If further cleaning is required, use a special treatment or make a paste to the consistency of
syrup using a mildly abrasive alkaline cleaning powder and clean water. Apply the paste
uniformly.
Then use a stiff bristle brush with additional water and scrub vigorously, adding more cleaning
powder if necessary. Rinse thoroughly and dry.
MAINTENANCE OF FLOOR MARBLE
For honed marble used as traffic surfaces care should be taken to prevent accumulations of
liquids or other materials that result in safety hazards and staining. Regular daily mopping
should be performed. Floor marble is any honed finish that is used as a traffic surface. These
surfaces should be mopped and scrubbed in a manner that will not leave a hazardous slippery
film.
Again, wet with hot, clean water and then lightly sprinkle an abrasive cleaner (i.e., a chlorine
bleaching type household scouring cleanser) over the wet stone, or put 1-2 handfuls into a
pail of 2-3 gallons of hot clean water.
Using a scrubbing motion, mop the marble surfaces with this solution (or with hot clean water
if you are sprinkling the cleaner directly on the stone.) Rinse with clean hot water and dry with
a mop or cloths. Power scrubbers can also be used for the procedure.
MAINTENANCE OF FLOOR MARBLE (Continued)
Often it is also desirable to protect special interior areas and to enhance the coloration of
honed marble in areas where a polished finish is not practical. In such cases sealers may be
applied after the marble has been cleaned. This minimizes maintenance and prevents
staining - especially around toilets and urinals in restrooms or in food preparation areas and
busy building entrances.
Sealers should only be applied to clean interior marble. Always follow the manufacturer's
directions for proper application. Terrazzo sealers are excellent for this purpose. So are
silicone-based stone sealers.
In all cases, sealers should be made of a clear, hard finish type suitable for traffic surfaces
and definitely non-yellowing. Do not use soft finish waxes, paste wax or resins. These
coatings can collect dirt and grit. Some acrylic-base liquid floor waxes can be used in place of
permanent sealers, but may give limited life.
SPECIALTY MARBLE FINISHES (APPLIED BY MARBLE CONTRACTORS)
Specialty finishes are surface finishes put on by individual marble contractors (other than
polished or honed) under trade names, and most are copyrighted or patented.
Examples of types of these specialty finishes are polymer coatings, texturing treatments, and
a variety of chemically produced surface conditions.
These specialty finishes are provided to meet the requirements of special areas that need
special stain resistance. For example: Polymer coatings are provided by contractors for
liquor dispensing and food-service tops, or textured surfaces are specified for special lighting
effects, decor enhancement, graffiti resistance, and maintenance reduction.
Your supplying marble contractor can give you the best assistance in maintaining and
applying remedies to their specialty finish. Always request this information upon installation,
but chances are you, as the acting executive housekeeper did not have the opportunity to do
so when the facility was built. See if you can track down the marble contractor if you are
experiencing maintenance difficulties.
STAIN REMOVAL TIPS
Several marble poultice base powders are currently available to commercial users. These
powders require only the addition of plain water for activation, are not acidic, and are much
more convenient than formulating your own poultice.
Stains in marble wilt generally be caused by one of three major category sources: Organic
materials, Metallic materials, or Oils and Greases.
STAIN REMOVAL TIPS (Continued)
If applying a poultice fails, chlorine bleaching, household ammonia or hydrogen peroxide in a
6 hair bleaching solution treatments may be used to remove organic stains. Organic stains
such as food and tobacco stains, bird droppings, leaves and bark may cause pinkish-brown
stains in the presence of moisture. Outdoors, with the sources removed, normal sun, rain and
weather will generally bleach out the stains, but indoors, hydrogen peroxide or chlorine bleach
soaked in a blotter or sponge will do the job. Or, these can be mixed into a poultice form with
plaster.
Urine stains, if long seated due to neglect, should be attacked with a strong chlorine-bleach
poultice or specially formulated commercially available treatment. Usually treatment requires
that the poultice or treatment be left on overnight. The chlorine-bleaching powder cleansers
can be sprinkled on, dampened, and left overnight as a periodic preventive measure also.
REMOVING METALLIC STAINS
These stains are generally red-brown, resembling rust. They result from the action of
moisture on iron or steel debris on the marble floor which may be loose or imbedded.
First, remove the sources: moisture and the metals. Clean and paint any metallic surfaces in
contact with the floor, or use pads under them, if they are parts of furnishings or fixtures.
Superficial fresh stains will usually come off with vigorous rubbing. Seated stains can be
removed by the application of a commercial "Naval Jelly" or other rust-remover product. If
these remedies fail, abrasion with a scouring powder following with the application of a rust
remover will remove the stain. If this should fail it is possible that you have imbedded, deep-
seated stain that cannot be removed.
REMOVING COPPER AND BRONZE STAINS
These stains appear in marble as green or muddy brown colorations and result from moisture
on loose or imbedded bronze, copper and brass items. Coating the items that are causing the
trouble with a quick-drying, clear coast such as a shellac, varnish, or a plastic coating
removes the source of cuprous metal oxidation. Then attack the stain with a thick poultice of
plaster or laundry whiting ammonia, Ammonium Chloride (or household ammonia and salt
mixed in equal quantities.) Apply the poultice thickly over the stain and surrounding area and
leave to dry. Remove with a non-metallic spatula and rinse. Repeat if necessary.
REMOVING INK STAINS
Ink stains can be removed in the same manner as recommended for iron stains, if the ink is
formulated from metallic salts. If these procedures fail, then the ink is probably non-metallic,
and can be removed using a poultice or blotter soaked in wood or grain alcohol, followed with
a flushing of household ammonia. Often a bleaching poultice will be needed also to remove
remaining coloration. Also there are commercially available special treatments for the
removal of ink-based graffiti.
REMOVING OIL AND GREASE STAINS FROM MARBLE SURFACES
Oil, grease, linseed oil and perspiration stains normally must be dissolved chemically. Use
extreme care, because some of these treatments are flammable and explosive. Acetone is
widely available solvent that produces good results on most oils and greases.
Mineral spirits and unleaded gasoline can be used as a substitute for acetone. Apply in a
poultice or with a saturated blotter and allow to dry. Repeat if necessary.
PAINT AND STAIN REMOVAL
Normally latex and acrylic paints will not stain marble. Oil-based paints, linseed oil, putty, and
architectural grade caulks and sealants, however, do cause oily stains.
Paint should be removed with caution and only with commercial-type "Heavy Liquid" paint
stripper. Take care to flush the area thoroughly after application of the stripper. Take care to
flush the area thoroughly after application of the stripper. Use' only wood or plastic scrapers
and still fiber or jute brushes for removing the dissolved paint. Do not use acids or flame tools
to strip paint from marble. When removing paint and paint stains from vertical surfaces, take
care to prevent runoff. If runoff occurs, wipe immediately with a cloth dipped in a bit of
acetone to preclude oil staining. Latex paint requires only wiping off with a damp cloth.