Q. We had one of our bathrooms remodeled and a new tile shower installed about six years ago. About a year ago I noticed grout on the shower floor was covering the tile in one section. How could this happen? Has the shower settled? Also, a little bit of the grout on the edge of the shower has broken up. It seems too soon for this to be happening. I also noticed that the ceiling below this bathroom (it’s a closet in a half bathroom) has water stains. I don’t know how long the stains have been there. Are the problems related? What should I do?
PC, Easton
A. I reached out to Ted McFadden of www.easy-stonecare.com who wrote the book “Stone Care Guide.’’
Ted says you are seeing minerals from the wicking up and evaporation of water over time. This phenomenon is similar to the formation of stalactites and stalagmites in caves. The leak visible on the lower floor is probably related to the problem. Shower floor drains are composed of two openings. The main drain is the one that we see. Below this is the drain for the shower pan, commonly called the “weep holes.’’ When the weep holes get clogged and the grout on the floor fails, the pan will fill up with water. Weep holes can be clogged for a number of reasons.
Regardless, the water has to go somewhere. It will start to mold, mildew, and rot the setting bed and can cause waterproofing failure. Though it is not conclusive, this could be what is happening on the lower floor. Only opening the ceiling below will provide any proof of waterproofing failure.
Again, the water has to go somewhere, so it will start to evaporate up through the floor. As this happens, minerals are left behind. This problem has probably existed for years.
This shower should be torn out, re-waterproofed, and replaced by a licensed tile installer with good shower-installation skills. You can find helpful information on this type of installation at the Tile Council of North America website (www.tcnatile.com).
Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to homerepair@globe.com or tweet them to @globeaddress or @robertrobillard.
