I work on travertine at least once a week, I dropped the ball on this estimate being lazy 2 weeks ago, sometimes you never know what a homeowner has done to their floor. I ran into a situation today where the travertine was coated with a clear wax and the grout was colorsealed and several grout areas blew out, lucky for me I carry several bags of basic colors of N/S and Sanded grout, general floor stripper and Color Clad on the van. Be prepared
