QUESTION

Grout Cracking Problem - We had new tile floor installed over wood sub floor.The problem is the tile grout keeps cracking.the floor is apprx.600 sq.ft.I think the floor was properly prepared befors installing tile and would like a second opinion.

ANSWER

ANSWER - Generally when there is a problem it is due to compounding factors. Your wood subfloor may not have the correct configuration or it may not have been constructed correctly that is resulting in excessive deflection within the floor. Or perhaps this is a backerboard installation over the wood subfloor and it isn’t properly attached. Or perhaps the ceramic tiles are not bonded properly to its substrate and they are coming loose causing the grout to crack. Or it may be a combination of all those issues.

We can evaluate the tile installation and determine if there are deficiencies and what the likely cause of the problems are. To fully evaluate the wood subfloor configuration to see if it complies with the IRC (International Residential Code) standard would require having a structural engineer specializing in wood subfloor assemblies evaluate it.