About to install 100sf Saltillo 12x12 in kitchen. Going over floor approx 3" tongue and groove boards over joists 16" O.C. Boards are
3/4". Option #1: Hardibacker (or HB500?) Option #2: Schluter-Ditra I am really keen on using the Ditra, as it has just become avaliable to me and it seems like a quality product. Anyone have an opinion?Should I install 5/8" plywood before underlayment?