CLEANING AND MAINTAINING STONE
Part One
Introduction
Stone you have purchased for your house, apartment or business space is an
investment which will be of good service to you for a long time. Stone is a natural
product and applying simple care and maintenance will make it keep nice appearance.
I will mention a few useful tips for maintenance and routine cleaning as well as
simple techniques for removing stains.
Get to Know Your Stone
According to its composition, natural stone can be classified in two basic categories:
siliceous and calcareous. When choosing cleaning agents it is very important to
differentiate them.
Siliceous stone mostly contains quartz (SiO2), and compounds containing quartz. It is
very stable and it is relatively easy to clean it with mildly acid cleaning products.
Granite, sandstone, slate, quartzite and schist belong to siliceous stone.
Calcareous stone mostly contains calcium carbonate (CaCO3). It is sensitive to the
effect of acid cleaning products and demands a different cleaning procedure from
silicate stone.
Marble, travertine, limestone and onyx belong to calcareous stone.
How to Tell Them Apart?
It is possible to do a simple test which shows whether the stone is siliceous or
calcareous. All you need is several drops of vinegar and a dropper. While performing
the test stone can be permanently damaged, it is desirable to apply vinegar on an
unnoticeable surface (inside the closet, in the corner) and away from the mortar joints.
It is rather simple to perform the test: take a dropper to apply several drops of vinegar
on the area about the size of a coin and observe. If the stone is calcareous the vinegar
will more or less etch the stone. If little or no reaction occurs, the stone is siliceous.
After you have done the test, thoroughly wipe the area with clean water and dry it. If
you still suspect, call the stone expert.
Color and Appearance of Stone
Granites and marbles with varying mineral composition in a variety of colors are
quarried throughout the world. In most cases types of granite and marble can be
differentiated according to visible particles on their surfaces:
- Marble usually shows “veins” or high concentration of minerals;
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The minerals in granite usually look like small flecks distributed uniformly
inside the stone;
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Sandstone varies a lot in color due to different minerals and clay it contains.
Sandstone is light grey to yellow or red;
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Limestone is usually light grey, beige, tan or buff. A distinguishing
characteristic of many limestones is the presence of fossil remains, often
visible in the stone surface. It is widely used as construction material;
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Slate can be green, black, grey, dark red or multi-colored. It is most commonly
used as material for floors and roof tiles and it is often distinguished by its
distinct cleft texture.
Each type of stone is unique and different in color, texture and other characteristics.
Stone Finishes
A polished finish on the stone produces a glossy surface which reflects light,
emphasizes color and marking of the material. This type of finish is commonly used
on walls, parts of furniture as well as floors.
A honed finish is a satin smooth surface which casts off just a bit of light. It is used
mostly for floors, stair treads and other quite passable surfaces where polished finish
would wear off fast. A honed finish can also be used for parts of furniture and other
surfaces.
A flamed finish is a rough textured surface most often used on granite floors and
stairs.
Protection and Precaution Measures
Always use coasters under glasses, especially those containing alcohol drinks or citrus
based juices. A great number of drinks and food we use every day contain acids that
can etch or dull the surface of some types of stone.
Avoid placing hot items directly on the stone surface. Use coasters, trivets or mats
under hot dishes, porcelain, ceramics, silverware and other objects that can scratch the
stone surface.
Cleaning Procedures and Advice
Floor Surface
Clean interior floors as often as possible using a clean, not treated dry dust mop. Due
to their abrasiveness sand, dirt and grit do the most damage to stone surfaces.
According to researches a person needs about eight steps on average to remove sand
and dirt from the bottom of their shoes. Doormats or rugs at the entrance as well as
carpets in the rooms considerably reduce the scratching of stone floor with sand and
dirt.
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Never use vacuum cleaners that are mechanically damaged. Worn out metal or plastic
attachments and wheels may scratch the stone surface.
Other Stone Surfaces
Clean stone surfaces with a neutral cleaning product, mild soap or mild liquid
detergent for dish washing and warm water. Use a clean cotton mop for floors and
soft cotton cloth for other surfaces. Too much cleaner or detergent may leave a film
and cause streaks. Do not use products containing citric acid, vinegar or some other
acid on marble or another limestone. After cleaning, thoroughly rinse the surface with
a mild solution of detergent, then water and dry it with a soft cloth. Change the rinse
water frequently. Never use powders or cleaning creams. These products contain
abrasives that may scratch the stone surface.
Bathroom and Other Wet Areas
Bathroom or other rooms which often get wet have a problem with the layers of
detergent and soap scum. These problems can boil down to minimum by a regular use
of mop or swab with rubber edge. In order to remove soap scum from the stone use a
non-acidic cleaning products or ammonia solved in water (about half a cup of
ammonia mixed with four liters of water). However, it should be mentioned that
frequent or excessive use of this solution can lead to stone darkening or loss of shine
(matting).
Stains and Spills
Stains on stone can appear due to numerous reasons. It is difficult to clean them if a
possible cause of their appearance is not immediately removed. For example, spilled
liquid should be immediately covered with a paper napkin, serviette or tissue, and
then carefully removed. Don’t rub the area, that will only smudge the spill. Use mild
soap and warm water to wipe the stain, and then rinse several times with clean water.
Dry the spot with a soft cloth. Repeat the procedure if needed. If the stain still exists,
use one of the products for stone cleaning in order to remove it.
Stain Removal
Identifying a type of stain on stone surface is a key to its removal. Always try to
determine that before start cleaning. Where is a stain located? Is it next to the
flowerpot, dining table or toilet cupboard? What color and shape is it? What was
happening or is happening near the stain?
Surface stains can often be removed with an appropriate cleaning products or
household chemicals. Deep-seated and hardly removable stains may require the use of
mushy covering (so called “dough”) or help of a professional.
Overview of particular types of stains that you can come across in the household and
overview of appropriate household chemicals are given below.
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Types of Stains and First Step in Cleaning
Organic stains (tea, coffee, fruit, food, tobacco, newspapers, leaves, bark, urine, bird
droppings). They can go from pink to brown and most often disappear after the source
of the stain has been removed. Outdoors, with the sources removed, the effect of sun
and rain will bleach the stain. Indoors stains are removed using a 12% hydrogenperoxide solution (hydrogen, suitable for bleaching hair) with several drops of
ammonia.
Water spots and rings (surface layer created after the evaporation of ''hard'' water).
Stains are removed mechanically by using fine steel wool (0000).
Etch marks are caused by acidic substances left on the stone surface. Some materials
will damage the stone finish, but not leave a stain. The others will both etch the
surface and leave a stain on that spot. Moist the stone surface and apply a product for
stone polishing. Rub the product for polishing into the stone using a soft cloth or by
using a buffing pad with a low-speed power drill. Continue polishing until each mark
completely disappears and the stone surface shines. Damaged areas that you could not
polish by yourself should be treated by an expert.
Efflorescence is the name for a powdery substance which sometimes appears on the
stone surface. It is caused by water which dissolves mineral salts of stone interior and
takes them to the surface, where after water has evaporated they remain in the form of
powdery material. If the stone has been put up recently, wipe the powder with a dry
cotton cloth or vacuum it. There is a possibility that you will have to repeat this
several times as the stone dries out. Do not use the water to remove the powder. That
is a bad solution because it will remove the powder only temporarily, and the problem
will remain. If the problem persists, contact a stone expert to help identify and remove
the cause of stone's moisture.
Scratches and Nicks. Slight, shallow surface scratches may be polished by using a
fine steel wool (0000); or refer to the section Etch marks. Deeper scratches and nicks
in the surface of the stone should be repaired by a professional.
What to Do and What Not to Do
Regardless of the type of stone and finishing:
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Dust mop floors frequently,
Clean stone surfaces with mild detergent and mild soap,
Thoroughly rinse and dry the surface after cleaning,
Blot up spills immediately,
Protect floors surfaces with carpets and rugs
Never use vinegar, lemon juice or other acidic products for cleaning marble,
sandstone, travertine or onyx surfaces,
Never use cleaners containing acid, such as products for cleaning bathroom
and kitchen,
Never use abrasive cleaning products,
Never mix chemicals if you are not an expert,
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Never mix different cleaning products, unless directions specifically instruct
you to do so.
If you cannot solve a problem by yourself, seek expert's help.
Development & Production Center Hemi Eco
Srecko Stefanovic
Belgrade, 2010
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