Poor Tile Installation
When we get a call about tile concerns, the most common issue is cracked or missing grout. In some cases, the grout might start to crack within a few months or at times, years after the tile being installed. If the cracked/missing grout is really bad, more than likely there will be tiles that have lost their bond to the thinset. The homeowner will state the installer blamed the grout, deflecting the blame. In some cases, to try to fix the issue, the installer will remove the cracked and loose grout and regrout the area. That may work for a few months and then the grout cracks again. The consumer calls the installer once again and the installer continues to blame the grout. After further investigation, the issue has nothing to do with the grout or how the grout was placed, it has to do with how the tile was installed.
CRACKING/MISSING GROUT
Grout cracking is the first indication that there is something wrong with the tile installation. Grout is the weakest link and will be the first thing to fail.
One of the most missed steps in tile installations are movement joints (expansion spacing) which include soft joints every 25 feet in either direction. Picture an open floor plan kitchen/dining area and adjoining hallway. There needs to be a soft joint in the doorway to the hallway, that is a change of plane. The floor in the kitchen/dining area expands and contracts at a different rate than the hallway.
In a shower, changes of plane are at the tub or pan in the shower, at the inside/outside corners, and other places like seats and niches. Color coordinated silicone caulk is to be used instead of grout in those areas. Don’t forget that walls in homes and commercial applications move ever so slightly and “when” they do, not if, the grout will crack if not installed properly.
Are you aware that grout has less compressive strength than drywall? And did you know the sheer strength of thinset is less than the compressive strength of drywall? Cracking grout can start in one area and affect just that one area, and sometimes it can affect the entire installation.
Tile needs to be able to expand and contract most especially when it is exposed to direct sunlight exposure. Some years ago I was asked to inspect a floor in the kitchen/dining area of a home where the tile floor had heaved. The homeowners said it sounded like a shotgun had gone off. This floor had been installed for years with no issues at all until January/February here in Northeast Ohio. During my investigation I found that the tile had been grouted in net to drywall and thresholds to other rooms. I noticed a great deal of direct sunlight exposure on the floor. I looked out the south facing windows and noticed stumps left in the ground from evergreen trees that had been cut down.
I asked more questions:
When did you have the trees cut down? “In the fall”.
In years past have you ever had direct sunlight exposure on the floor? They said “no, we love it”.
When the floor was installed, the installer did not leave the proper expansion space. The first time the floor received direct sunlight exposure, the sunlight caused enough thermal expansion to cause the floor to expand and having no place to expand, it heaved. What feels like a small change (cutting down trees) had a large impact on the flooring.
PROPER BONDING
A poor tile installation can be from many factors. One is the tile was not set properly. In this installation, the tile never bonded properly to the thinset because beads of thinset overlap. When this happens, air is trapped under the tile, preventing the back of the tile from properly bonding to the thinset. These installation failures do not just happen with tile on floors, it also happens with tile on the walls in showers. A great reference to understand how to trowel thinset is the video from the NTCA called “Trowel and Error” (youtube.com/watch?reload=9&v=TMb_EOyRdn4). It shows how to properly trowel thinset with all the beads going in the same direction as to help direct the air.
INDUSTRY STANDARDS
A properly installed tile or stone floor will last a lifetime, as long as industry standards and guidelines are followed for installing tile: American National Specifications For The Installation Of Ceramic Tile ANSI A108/A118/A136.1:2024, The Tile Council of North America (TCNA) Handbook for Ceramic, Glass, and Stone Tile Installation, and the National Tile Contractors Association (NTCA) Reference Manual.
BOTTOM LINE
Cracked grout, while it can be corrected, does not address the underlying concerns of a poor tile installation. A poor tile installation will continue to degrade over time and continue to fail. This is especially of concern in a wet area like a shower, as the water can get behind the tile and cause unseen issues such as mold and mildew. If the shower was not waterproofed correctly, rot can happen on studs and joists.
Tile installation is almost as much an art as a skill. Good tile installers are worth their money.