Suppose you have an interior granite wall that had some silicon caulking used in the grout joints. The silicon then caused staining along the grout edges. A poultice successfully removed the staining, but then later, the stains reappeared. What... Read More

Q. We have mold buildup in grout joints and surface has film on it. What is best to clean mold and remove film from surface?   A. There are several cleaners that will remove the mold but you must be careful to choose one that will not damage the... Read More

Q. Hello. I just received a new quartzite install, and there is a crack at the sink extending to the hole for the soap dispenser. The fabricator claims it does not affect integrity of the stone, since apparently it's not a full-depth crack. The... Read More

Q. Does grout turn darker when wet and lighter when dry even with color seal? A. Unsealed grout has tiny pores that absorb moisture, which can give unsealed grout lines a darker appearance. Once the moisture evaporates (assuming the moisture is... Read More

Q.  I just finished putting in a new black marble shower wall, literally giving it its first cleaning. I had no idea that some bathroom cleaners would immediately etch into the marble finish. Please, for the love of God, tell me there is something... Read More

Q. I hired a cleaner and she used limeaway with mold control from Clorox. And it appeared to have left white stains in my bathroom stone tiles. These don‘t wash away with water. What should I do? A. Unfortunately, this is not a stain that you... Read More

  Efflorescence - Removal and Prevention   By Frederick M. Hueston www.stoneforensics.com The crystallization of soluble salts in Historic masonry causes severe deterioration of the substrate. This crystallization is called... Read More

[Fabrication Company] installed Kashmir Gold granite kitchen countertops in our home and the surface tops are yellowed and the bullnose edges are without yellow. We complained immediately during installation and they promised that their polish would... Read More

The white deposits are salts, which are bleeding through from the grout joints or from the mortar. An acid wash will be required to remove the salts. If the deposits are heavy, try scraping them off before washing the slate with acid. Several acid... Read More

Several excellent grout cleaners are available from your stone care supplier that will not dull polished marble. Try a mild solution of bleach ; use a soft tooth brush to apply the solution to the grout joints and scrub lightly. TIP If the grout is... Read More