BATHROOM CASE STUDY: BEWARE THE BUILDER SHOWER

A client in Bryn Mawr called asking if I could do something with their shower. The problem they were having was mold and mildew growth. At the time, they were not looking to renovate and wondered if I could do something to address this issue.

My first instinct is always to start simple and take it from there. I assumed the problem was that the only ventilation for the shower was a tiny 4-inch opening above the shower door. With that design, the shower could never air out, and all that condensation allowed mold and mildew to thrive. We opted to bleach the mold. Coat the ceiling with an oil-based primer, paint the ceiling with specialty bath paint, and install an exhaust fan directly in the shower area. Two years later, the problem, while somewhat better, remained.

Upon returning, I noticed the baseboard outside the wet area also suffered from mold and mildew growth. This was a sign that there was a significant problem going on with this shower. What threw me was the fiberglass shower pan. There was no way this shower pan was wicking water to the exterior of the shower. Together, the clients and I decided that I would tear out and rebuild this shower.

While doing the demolition, I was concerned that only a cement board was behind the tile with no waterproofing. However, the studs behind the cement board showed no signs of water damage or dampness. But the absolute horror came while demolishing the old shower bench.

The support for the shower bench was constructed of pressure-treated 2x4s screwed to the stud walls and just sitting in the fiberglass pan. On top of this, they set their cement board and tiled it. There was no waterproofing anywhere. The support studs were soaked and utterly black with mold. Since this bench frame was in direct contact with the wall studs, all that moisture was wicking into the studs, drywall, and baseboard. The source of the problem was now apparent.

This bathroom was part of an extensive 2nd-floor renovation done circa 2006. While the builder did a fantastic job in all other areas of this renovation, they fell flat on this shower. I assume they hired a tile subcontractor to build this shower, and the builder didn’t know enough to know it was being built wrong. Many tile contractors don’t know the first thing about setting a bathtub, let alone building a shower. A beautifully tiled shower is useless if the shower is not constructed correctly.