Natural Stone Damage
Alkaline strippers, ammonia and heavy duty stone cleaners is caused by alkaline salts contained in cleaners that are deposited below the surface of the stone and appear as etch marks.
A polished marble, limestone or travertine may need to be honed and polish at the etched area. If the etch area appears light, the etched area may be polished from the stone. CRYSTALLIZATION
Crystallization is a process used to polish marble.
When this process is overused it can build up and turn yellow on light color stones. It also may give the stone a plastic look.
Once coating is removed chemically, honing and polishing will be necessary.
Dry white powder on the surface of the stone. Most of the conditions that cause efflorescence are water related and will continue to be a problem unless the moisture is eliminated. Do not use any water based cleaners remove efflorescence, this will only cause more efflorescence. The stone has to dried and then sealed before attempting to remove efflorescence. If the efflorescence condition is indoors it sometimes helps to install dehumidifiers or turn the air conditioner down to about 72 degrees F. It can take several months for the stone to dry to completely eliminate the problem.
Stun marks caused by heavy objects dropped on a marble floor, also high heels can leave stun marks. Stun marks can telegraph to the bottom of the stone. They are caused from the individual crystal in the stone exploding.
Grinding, honing and polishing the floor may eliminate some light stuns but chances are they cannot be removed.
Circular pattern swirls. Swirls marks appear as circular patterns on the surface of the stone. Usually caused by a floor machine using abrasive or polishing pads have trapped sand or grit under them. Light swirls may be removed by polishing. Heavy swirls will require honing and polishing.
There are several types of thin stone tiles are very susceptible to warping. Many of the green marbles and a few agglomerate marbles are known for this warping condition. Many installers have had the surprise to find that there tile installation has become warped overnight. Why does this a happen and can it be prevented. Warping is caused by water. Green marble set with any water based material will have a tendency to warp. The mechanism of why the tile warps is somewhat a mystery. Some believe that the water fills the pores of the stone and when the water evaporates the orientation of the stones crystal change and cause it to warp. Whatever the reason, one thing is for sure, green marble can warp when set with water based materials.
Once a green marble tile warps it is difficult to repair. Attempts have been made to grind the tile flat, but this usually fails since additional water is introduced during the grinding process. The green simply warps again.
The only way to prevent warping is to install it properly with a non-water based material such as epoxy. Some installers have also been successful in sealing the back of the tile with epoxy and installing it in a water based system. Do not attempt to seal the back of the tile with a silicone sealer. The silicone acts as a water repellent and will cause the setting material to fail resulting in a bond loss.
There are many causes for yellowing of stone: UV light can cause yellowing over time. Iron contained naturally in stone can oxidize and cause yellowing. Inexpensive coatings can cause yellowing. Mastic used to set stone can yellow.
If the yellowing is caused by iron contained naturally in the stone, there may be a moisture problem causing the stone to rust. Or if the yellowing is caused by waxes or coating strip them off according to stripping directions (see waxes).
Stone Damage Examples
- 1. A cleaning person used a well - known glass cleaner and it was spilled on the marble floor that was in the bathroom and the marble vanity top as well. This common glass cleaner contained vinegar which is acidic can burned or etched the stones finish.
- 2. The builder that didn’t cover to protect a very expensive natural stone floor during the construction process suffers as contractors left their tools on the unprotected floor and did the same and the countertops leaving scratches and stun marks.
- 3. The home owner had let the granite countertops be used as a step ladder to change the recessed light bulbs causing the granite to break and developed cracks at the front of the sink and where the drop-in stove top were.
- 4. A polished marble floor had wine and citrus drinks spilled from a party and was not cleaned up soon enough causing he polished marble to be etched where wine and citrus type drinks spilled.
- 5. The home owner thought he could use sandpaper to remove a scratch from the polished granite countertop causing deep scratches from the sandpaper were worse than the single scratch that was to be removed.
- 6. A stone mason did a beautiful job installing an exterior stone patio, and sealed the stone with an exterior wood deck sealer causing the stone to hazed white color and no longer was a beautiful stone patio.
- 7. Someone was trying to remove rust from a faucet and didn't know the stone was acid sensitive causing etch damage. Most rust removers contain acid.
- 8. A stone fabricator installed a countertop and did not get the seams of the stones together correctly and did not match the color of the joining adhesive causing uneven seams and a noticeable color separation where the stones had been joined.
- 9. An appropriate natural stone impregnating sealer was applied, but excess sealer was not removed resulting in a residue that was tacky to the touch an undesirable appearance.
- 10. The home owner drops a plate and chips a large piece of stone from their granite countertop and lost or threw away the stone chips when chips could have be attached back.
Most damage to the natural stone cases above can be repaired by a natural stone restoration specialist to not be perceivable, as though it never happened.