Nothing can be more disheartening than laying a tile floor only to have the grout crack soon after. David Pinsley of First Rate Renovations, Inc. and Cultured Marble Products in San Leandro, California, serving the Bay Area, discusses here the reasons grout might crack.
If you are facing cracking grout, especially when it comes to newly installed flooring, it can be difficult to ascertain why. In fact, it would be impossible to give an answer without first making a thorough inspection of the site, and looking at your construction details. Saying that, there are a few speculative answers I can give which will cover several eventualities.
Cracked grout that is virtually coming out of the joists could occur because of:
- A combination of poor quality grout mixed with bad mixing additives: It could be the water that was added or even something such as an old latex additive that expired way beyond its shelf life. Weak grout is often the culprit behind cracking, and the glue applied over the mortar in many cases can cause cracking as well.
- Poor installation: Substandard work could mean the grout could not penetrate well enough into the grout spacing. It could even be that sanded grout was used instead of non-sanded when the reverse was needed, or vice versa.
- Bad preparation of the underlay, which could cause movement underneath: Was the floor underneath, such as a cementious board, secured properly?
- Check the construction of your sub flooring: Some floors should be floated with a mortar bed prior to installation. If not, then not only will your grout crack, but your tiles may eventually crack as well.
If you are facing cracked grout, it’s important to find the cause so as to not repeat the mistake. A professional to rectify the situation, especially so he can fix the grout before the tiles begin to crack as well.
