Question: Everything about installation that I see involves a concrete or rock base. I am interested in installing Travertine (tiles?) on a raised, covered porch. The intent is to install a base of thick (3/4") plywood, onto which the Travertine would be installed. Is this possible? Advisable?
Answer: In order to install thin (.5" thick) Travertine Tiles on a plywood subfloor, you need two layers of plywood - totaling 1 1/8" minimum - and then 1/4" cementboard or Ditra on top of it. The reason for the cementboard/ Ditra is that if the floor "bounces" as you walk over it or shrinks and expands with humidity, the grout and/ or Tiles will begin to crack over time.