Tiled Showers

Homes have many areas that can be problematic—crawl spaces, chimneys, decks, et cetera. Tiled showers can be problematic, too. I estimate approximately 75% of the tiled showers I’ve inspected have some issues, and, for most, they’re related to moisture.

The primary reason for the issues arises from improper installation—especially related to the drain. Though some of these shower failures can be related to the drain pan liner, this article is not addressing the drain pan liner failures.

The high failure rate is because of tile installers’ lack of training or knowledge for proper installations. Most anyone can install tiles. Whether remodel work or new construction, often the installers are not certified tile installers. Until a few years ago, I did not know certified tile contractors existed. Similar to being an ASHI-Certified Inspector, their certification requires passing a written exam as well as demonstrating their abilities in an actual tile installation.

More than 10 years ago, while attending training from my local ASHI chapter, there was a representative from a major manufacturer who makes products (mortar, grout, etc.) for tile, stone, and similar installation. During the training, the instructor said, “Tile and grout should never crack. If cracks are present, it is an indication of either improper installation, structural movement, moisture issues, and/or a combination of all the above.” At the time, I thought he was just deferring responsibility for their products. A few years ago, while taking a completely different ASHI training course online, the instructor said, “Tile and grout should never crack. If cracks are present…” He repeated almost verbatim what I heard many years ago.

So, what is the cause of the high failure rate? It is related to the drain. The drain has two areas for drainage—one at the top, which we can see on the tiled floor. The other area for drainage is the weep holes below the tile and above the shower pan liner. If the floor/drain pan is properly installed, it is designed to allow the flow/drain into the weep holes. Often the area around the weep holes is improperly installed, and the weep holes get clogged, preventing proper drainage.

Because the water cannot drain properly, it must go somewhere. So, it starts to rise. As the water rises, this creates hydrostatic pressure. This pressure causes cracks to form in the grout and/or tiles. You may also see calcification in these areas, and the pressure forces the minerals in the grout, thin set, et cetera out. The water over time can rise above the drain pan liner, over the curb, and onto the substrates in and around the shower area. When I was a child, I was taught that water always runs downhill. This information was false. Water can move vertically, horizontally, and downhill.

Once the water breaches the liner, any porous surface will absorb the moisture. This includes the floors, walls, and other components. Because the absorption is a “wicking” action, often there is no visible evidence of the leaks like we see in drain pan liner failures. The wicking is a slow process. There can be significant moisture damage, and it goes unnoticed in our visible inspections.

On an inspection several years ago, the sellers wanted a pre-listing inspection. During the inspection, I noticed a significant amount of bowing/buckling of the hardwood floors directly outside the primary bathroom in the bedroom. While inspecting the tiled shower, all of the red flags were present, and elevated moisture was detected.

When I inspected beneath this area in the crawl space, I found a significant amount of moisture damage to the subfloor that was starting to damage the floor joist behind the insulation. Due to the amount of damage, it was obvious this had been occurring for an extended period. When doing the review with the seller, I was informed they bought the house three years earlier, and they did not have the home inspected. This was a very large bathroom and bedroom. Considering that I did residential construction before becoming an inspector, I estimated the repair cost would be many thousands of dollars.

Expect pushback when reporting this finding. During the latter training mentioned, one of the attendees mentioned he gets a lot of pushback when reporting a similar finding. The instructor said that the sellers or agents are skeptical because there is often no visible damage. They may say things like, “I’ve never heard of this before. I don’t see any damage. The seller took a shower this morning,” and so forth.

Often this could result in costly repairs, and the only way to determine how much damage could be present requires dismantling the shower area, which could result in the buyers backing out of the deal. This does not go over well with sellers and their agents. I’ve had clients who experienced issues with tiled showers before talk about how much of a headache it was and how costly the repairs were. Some clients have told me if a home has tiled showers, they will not make an offer.

Proper knowledge and tools are imperative when we are reporting this. Because this is so common, I take a three-ring binder to show my clients during our review. I show them a diagram of proper tile shower installation and components, several photos of previous inspections with improper installations of the drain weep holes and damage ranging from none, minor to major damage. In my report, I have three video links related to proper installation of the drain weep holes as well as damage caused by improper installations. Having the right moisture meter(s) and knowledge of the moisture meters abilities is also critical. This is especially true with older tiled showers, as wire mesh was commonly used and easy for the moisture meter to give false/positive readings.

If you have not received training for tiled showers (and related bathroom components), it would be wise to consider it. With the proper training and knowledge, you may help clients understand the potential damage and costly repairs that could exist. In addition, this could help reduce the possibility of costly litigation and lawsuits for us.

Opinions or statements of authors are solely their own and do not necessarily represent the opinions or positions of ASHI, its agents, or editors. Always check with your local governmental agency and independently verify for accuracy, completeness, and reliability.