AboutBill Hohmann Expertise I can answer questions concerning the stripping and sealing of various tile, brick, and stone flooring with an emphasis on Mexican Tile. I cannot help in regards to installation issues, such as what sort of tile to use; how to install or remove tiles, etc.
Experience Over 30 years experience in the manufacture development and use of sealers, coatings and cleaners for tile, stone, brick, etc.
Question Hi Bill, we are installing offwhite honed limestone tile in a shower and just figured out that it is porous and will need to be very well sealed and maintained. I have a few questions. WHat is the best sealer to use for this application? I do not want the color to change if that helps. I see silicone impregnators, advance fluropolymers but no reviews to help me decide. Also, what is the best product to keep it clean...should I use one of these cleaners that includes a sealant?
Answer This is one of those questions to which there is no "best" solution.
Understand up front, the mineral in your water is going to have calcium in it, and your limestone is calcium (calcites). So if water deposited minerals get on the surface of the stone, it becomes the stone.
That said:
The fluoropolymers are very expensive, and are supposed to repel both water and oil. Also, on very porous substrates like limestone, you need to apply two coats wet on wet. That is, the first coat soaks in, and before that dries, you apply a second coat, basically saturating the stone.
I am not a big fan of this chemistry, or DuPont for that matter.
Silanes or siloxanes, when used properly, will keep water from wetting to the stone, and maintain the natural appearance, but like the fluoropolymer, water can still dry on the surface allowing calcite to become deposited. At least, you should be able to clean it off with a mild acid solution that would protect the treated calcite while dissolving that which was deposited by water. Like the other, silanes and siloxanes must be saturated to the stone with at least two coats wet on wet. You cannot successfully apply a second coat if the first coat is allowed to dry!
Film forming (resinous) sealers will darken the stone somewhat, but when applied into the onto the stone, will protect it, make it easier to clean, and water deposited minerals would be even easier to remove.
But, the best solution is to not use limestone to begin with. You would be so much better off using glazed tiles which require a minimum of maintenance.
