We recently installed Travertine on the kitchen floor with 1/8″ grout lines. The problem we are experiencing is the grout, in some areas, chips at the top. We thought the grout may have been too thick when we installed. Also, the grout used was unsanded. Do you have any suggestions? – Susan
Hello Susan. If you used grout without sand and the joint width is greater than 1/8″, then that could be part of the problem. Grout shrinks as it dries and the sand is needed to keep the ‘body’ of the grout strong. Actually, sand is always good for grout, but thinner joints just don’t allow enough room for cement and sand; therefore, unsanded grout is used in joints 1/8″ or smaller. There are exceptions to this but I won’t go into that detail here.
Secondly, if the grout was too ‘thick’ as you mentioned, I am assuming that is because there was not enough water mixed in the dry grout. This is most likely the problem and unfortunately created air pressure as your installer tried to push the grout into the joints. This would lift the grout when finished grouting. You will need scrape out the unacceptable or failing grout and simply re-grout with a loose/wet mixture. The good news is that this can be done successfully.