Restoring a Moldy Shower Floor
My bathroom shower pan has several areas where mildew has thrived, but no loose tiles and no problems at all with the tiled walls. The floor surface is properly sloped toward the drain, except for one corner where a little water accumulates. The mold appeared within a week of our moving into the 15 year old house and became severe very quickly.
I suspect the shower pan has clogged weep holes and incorrect slope in the cement bed. My goal is to restore the shower floor and avoid a costly shower pan replacement.
I've cleaned the grout with a carbide cutter to at least 1/8th inch, cleaned the surface with mildew remover and a stiff brush, and regrouted with cement-based grout. In some areas the old grout was soft and mushy over several inches; same thing for the caulking at the floor edges. In those places, I dug out the old grout all the way down to the cement base. I also siphoned out over a cup of moldy water from those holes with a wet vac before cleaning and regrouting carefully.
The new grout has now cured for five days and feels very solid. I'm ready to move forward and finish the job. I'm planning on a careful application of penetrating grout sealer and careful caulking with Geocel (there is still some dampness under the tile, so standard silicone bathroom caulk would probably not adhere well).
The under shower area is only damp now and I'm hoping that the new grout, sealer, and caulking will keep water seepage to a minimum in the future. Is there anything else I need to know to do the best possible job?
