STONE AND TILE TIPS FOR THE INDUSTRY
COMMON STONE PROBLEMS

1. Loss of Shine: The loss of the high polish on certain marble and granite can be attributed to wear. This is especially true of marble, since it is much softer than granite. The bottoms of ones shoe acts like sandpaper on a stone floor surface and overtime will wear the polish off. To prevent excessive wear, it is important to keep the floor dust mopped, place walk off mats at all entrances.

To repair a worn stone surface, it will be necessary to have a professional hone or polish it. The dull spot created when liquids containing acids are spilled on marble is called etching. Marble and limestone etch very easily. Serpentine and granite is more acid-resistant and will rarely etch.

2. Etching: To prevent etching, avoid using cleaners and chemicals that contain acids. Bathroom cleaners, toilet bowl cleaners, and lemon cleaners commonly contain acids. Certain drinks and foods contain acids and will also etch. Light etching can be removed with a little marble polishing powder. Deep etching will require resurfacing of the stone.

3. Staining: All stone surfaces can become stained very easily. Most foods, drinks, ink, oil and rust will stain marble. Once a stone becomes stained, it can be very difficult to remove. To prevent staining, clean the spilled material immediately. Blot the spill with a clean paper towel or cloth. If this does not remove the stain, then a process called "poulticing" may be needed. For more information on poulticing, please refer to our brochure "Removing stains from Marble, Stone and Other Porous Surfaces". To prevent staining, sealing the stone with a good quality penetrating sealer is important.

4. Efflorescence: Efflorescence appears as a white powdery residue on the surface of the stone. It is a common condition on new stone installations or when the stone is exposed to a large quantity of water, such as flooding. This powder is a mineral salt, from the setting bed. To remove efflorescence, do not use water. Buff the stone with a clean polishing pad or #0000 steel wool pad. The stone will continue to effloresce until it is completely dry. This drying process can take several days to as long as one year.

5. Spalling: Flaking & Pitting - If your stone is developing small pits or small pieces of stone are popping off the surface (spalling) then you have a problem. This condition is common on stone exposed to amounts of water or when deicing salts are used for ice removal. Like efflorescence, mineral salts are the cause for spelling and pitting. Instead of the salts depositing surface (effflorescence), they deposit below the surface of the stone, causing pressure within the stone and therefore the stone spells, flakes or pits. Unfortunately once it begins to spell it is almost impossible to repair. It is recommended that the stone be replaced.

6. Yellowing: There are several reasons why a stone will turn yellow. Embedded dirt and grime can give the stone a yellow, dingy look. Waxes and other coatings can yellow with age. Certain stones will naturally yellow with age. This is caused by oxidation of iron within the and especially problematic with white marbles. If the yellowing is caused by dirt or buildup, clean the stone with an.alkaline cleaner or wax stripper. If the yellowing is result of aged stone or oxidation, live with it. It is not coming out.

7. Uneven Tile Lippage: Lippage is the term given to tiles that are set unevenly. In other words, the edge of one tile is higher than the next. Lippage is the result of a poor installation. If the lippage is higher than the thickness of a nickel, it is considered excessive and the tile will have to be ground to flatten the floor. This will require the services of a professional stone refinishing contractor.

excerpt from Fred Hueston of the
National Training Center for Stone and Masonry Trades