QUESTION

Add more Grout over Shallow Grout Joints - I just purchased a house with ceramic tile. Whoever installed the tile didn't use enough grout between tiles. The spaces between tiles are very shallow. Can I fill these with more grout? It's been 3 years since installation.

ANSWER

ANSWER - Generally speaking you would need to first cut out the grout joints with a diamond blade saw and then re-grout the joints after they joints are fully open and clean.

If you don't cut out the grout, then normally you need at least a 1/4" in depth to apply more cementitious grout on top. First you would have to thoroughly clean the grout joints and then you would need to use a latex modified grout (add latex in lieu of water to grout).

Using an epoxy grout over the cement grout will allow you to have a thinner application, but the epoxy grout is more difficult to use and more costly. If you used this method you would need to fully clean the grout and let it dry and then apply the epoxy grout.

Always follow the manufacturer of the cementitious or epoxy grout instructions. Good Luck