[etinul]

Hello. I am an Architect who loves specifying natural stone on projects and used it extensively in renovating my NYC (Queens) home. I thought I knew how to maintain stone....but after 3 years I realize my maintenance efforts are seemingly useless.

I have two bathrooms. One has a Grey limestone (honed). It's name is Platinum from Stone Source. The other bathroom has green slate with natural cleft finish. I sealed both been with Lithofin PSI impregnator. My problems are as follows:

Platinum Limestone: the shower walls consist of a combination of 5/8" mosaic limestone and 3/8" thick limestone tile. The mosaic is fogging and seems to be decomposing at the base of the wall. The limestone tile, which frames the mosaic, is also presenting problems. The 4" portion, where the tile meets the top of the bathtub, is forming white spots which appear to be pitting the surface of the tile. All this began appearing about 3 to 4 months after the installation, which is approximately 3 years old. See attached pictures 1 and 2.

Green Slate: The problem here is the shower floor, which is made up of 8"x8" tiles (natural cleft). The floor tiles, again after a couple of months, began forming a whitish layer at the perimeter of each tile, like a 1" picture frame. This then began spreading, like a virus, to cover almost the entire tile at some locations. The chrome drain is also almost entirely encrusted by this white stuff, which seems to require scraping to clean. See attached picture. I gruelingly cleaned the tiles a couple of times in the past two years with Lithofin's heavy duty stone cleaner, which removed a good amount of the white stuff, and then resealed the shower floor. It looked ok for a while. The problem keeps coming back and now is in worse condition than ever.

I am really concerned about the limestone pitting, since the tile I used is no longer available. However, both are equally unsightly.