Q. I just had a new bathroom & shower installed. The floor of the shower is a one inch limestone mosaic tile - looks tumbled. (I also have it high on the shower wall as a border.) The folks that sold the tile (Mosaic Tile) said the floor use was fine – that the limestone should be sealed. My major concern, obviously, is water seeping through a) the limestone, b) the concrete pan, and c) the "rubber" pan liner. Additionally, I do not want water build up promoting algae growth. I would like maximize water flow down the drain. It is not a polished stone. Nor is the porcelain tile on the shower walls. I am not looking for polish. Will sealing help my me meet my objectives? How should the limestone floor be maintained? FYI, I purchased the maintenance off MB's site, but it doesn't seem to answer my sealing question. Thanks. Mike

 

Hi Mike. While it won't hurt to seal the limestone, sealing itself won't correct the errors of a bad install. What I am saying is that as long as you had a good install you wont have any problems. If the change of plane joints are properly caulked and the floor is properly sloped for drainage you should be fine. If the drainage is good and you have proper ventilation to dry the shower stall out then you shouldn't have any mold issues. Use a good stone safe cleaner and mildew stain remover for maintenance of the shower stall and use a squeegee every day.

 

As far as sealing goes, test the limestone by puddling a palm size puddle of water on the surface for 5-10 min. Wipe away the water with some paper towels and see if a darker mark remains (absorbant). If so use a water based sealer to seal. If it's a small stall you can spray or pour on the sealer and spread it out over the surface with a roller or lambs wool. Let it sit for 5minutes and then use paper towels are rags to remove all the sealer from the surface of the stone.

 

You can test the surface again in 4-5 hours and if it still absorbs water repeat the sealing proccess again.

 

Stu Rosen