Q. hi. i have a dark charcoal honed slate floor and walls in my bathroom - both in the shower area and outside. in the shower area along the seams of the tiles have developed white discoloration (liming?) how should i care for the flooring - both in the shower area and outside the shower area, and will this reverse the white discoloration or would that require other material. thanks very much.

 

A. This is a common problem with slate and other stones in wet areas. The problem is that the water is dissolving the setting bed and/or the grout and causing it to deposit on the joints.  It can be removed with some mild acids but you must be very careful to neutralize the acid by rinsing thoroughly. Once the deposits are removed you can seal the joints with a good quality stone impregnator, but make sure the joints are dry first. If you feel uncomfortable undertaking this project I would recommend that you hire a professional to make sure it is done correctly.

 

If you do need to hire a professional, you can find one in your area by going to www.stoneandtilepros.com/findapro.php