Re-grouting tile shower floor — found water under tiles

[Unregistered-baldheaded bird]

There are cracks in the grout in our 2nd floor shower in our newly purchased (built in 1985) home. The walls and floor of the shower are ceramic tile. As I was scraping out the old and loose grout at the edges and a couple of grout seams two feet long extending out from the drain water from under the grout seeping up. There must be water sitting in the shower pan because there is green mold in several places around the edges where wall meets floor and near the drain. There is some water leakage showing on the 1st floor ceiling below the shower. The shower is 5′ X 7′ and therefore has a custom made shower pan. I can’t bear the thought (or expense) of replacing it. QUESTION: If there is water under the tile floor and I regrout it and seal it and caulk around the edges, etc. will the water under the floor eventually dry up, or will the problem fester? I’m fairly positive the water got there through obvious cracks in the grout since it was not maintained for several years. Thanks for any helpful information.

[Unregistered-erik peterson]

Let the shower dry completely and the re-grout with dry-mix the way a professional tile-man would do…never use tube stuff (garbage) and/or silicone (garbage). I would set up a fan to circulate the air for several days to dry…test the pan when your operational again. erik

[tomh]

If water is penetrating the shower pan to the floor and ceiling below, the repair cannot be cosmetic. Grout is not intended to be waterproof. It is a cement product that bonds the tiles and can be sealed to resist most water to the back-side, but waterproof is not likely. In a 1985 home, the shower pan was most likely hot-mopped. This is a liner covered with a tar material, then a mortar bed applied and tile installed on top. If the liner has failed the solution is not the grout above, it is replacement of the liner; and that is the job you are avoiding. The use of caulk around the floor where it meets the wall may help. Caulk is a flexible sealant, and if the problem is really caused by leaks at the wall / floor seam, a silicone caulk may help. Grout should be sealed after repair with a penetrating sealer to make it as water resistant as possible.

If the problem continues, it would be good to have a look at the situation from below. That means making enough of a hole in the ceiling below, or from the wet-wall to see the source of the leak and what damage exists as a result. Drywall is easy to repair, but continued leaking can lead to problems that are not. Did you have a home inspection prior to purchase? Its surprising this problem went undetected. Perhaps the previous owners did not use the shower after the leak started.

[Author]

Posts