Cracking Grout Problem
Tile Shower With Cracking Grout in Springdale, Arkansas
A home owner in Springdale, AR had recurring problems with the grout cracking on the curb, on the bench, and at the wall-floor junction. The tile installation is only 2 months old.
The original installer used a traditional liner on the floor and standard sheetrock on the walls. No matter what type of waterproofing is used, this method will not work. After removing one tile from the curb and one from the bench, I find that this shower is doomed to failure due to the use of Hardibacker over treated wood. Treated lumber may prevent rotting, but it will still absorb moisture, resulting in expansion. Since no waterproofing was used over the curb or bench, water has migrated through the tile, Hardibacker and into the wood. The wood expanded and the grout cracked.
The original installer attempted to repair the grout using color-matched grout caulk. Cracking grout cannot be fixed with caulk. Color-matched grout caulk has limited uses, and a shower enclosure of this type is not one of the uses.
The use of sheetrock in a shower does not mean it isn’t waterproof. However, in this installation, a liner was used, but it did not provide complete encapsulation. The original waterproofing was not applied continuously over the wall and floor of the shower. With the sheetrock in contact with the mud bed on the floor, water wicked into the sheetrock.
During the demolition, I find the liner is not sloped, but flat on the concrete floor. This prevents proper drainage. The liner has also been cut at the top of the curb inside the shower, rather than wrapped over the curb and down to the floor. The tile on the top and front of the curb was bonded directly to the wood, causing the water that runs down the shower door to soak through the tile and grout and directly into the wood.
A bench constructed with dimensional lumber and ΒΌ” Hardibacker is inadequate for use in a shower. The top of the bench should have been covered with plywood, to provide structural support, and the entire bench should have been waterproofed. Mold has begun growing on the lumber and has soaked through the drywall and into the insulation behind it.
This shower was properly maintained by the home owner, but it still failed due to improper construction. This shower was a health and safety hazard, as well as being unsightly because of the cracking grout. Using good tiling practices for baths and showers will prevent these problems.