QUESTION

I run a small animal rescue and I'm redoing the floors so I can use a steam cleaner. I purchased glazed porcelain tile saw that state they are impervious to water. My animals occasionally spill their water and are known to have accidents. I am thinking my best option is to use an epoxy grout. If I'm using an epoxy grout, does it matter what kind of thin set I use?

My original floor is old hardwood, but most of it in my living room (their room is off my living room) had been cut out and replaced with subflooring before I bought it so restoring what this small room has is pointless. I'm going to put down cement backer board on the hardwood floors.

ANSWER

ANSWER - I am assuming that you are saying that you will be installing a porcelain tile over cementitious backer board that you will be attaching to a hardwood floor.

Make sure the floor does not have any deflection.  If it does then you will have to add bracing between your floor joists.

For a porcelain tile you need to use a modified thin-set mortar that at least meets ANS A118.4.   You will need to apply the thin-set mortar over the hardwood floor as you install the backer board.  This is meant to help you adjust the floors' flatness.  Screw the backer board down at least every 8" or as the manufacturer directions state.  Install the backer board sheets off-set from each other.  Leave at least a 1/8" gap between each backer board and fill with thin-set and tape with fiberglass tape per the manufacturers' directions.

Considering the hygienic conditions for caring for dogs, you should use a chemical resistant epoxy grout that at least meets ANSI A118.3 or ANSI A118.5.