I am in the middle of a kitchen remodel and need some guidance. Our original kitchen was linoleum when built in 1968, which the original owners covered in carpet. After demo, the original linoleum delaminated and came off in layers. We scraped as best we could but there is some remaining paper/felt layers permanently bonded to the subfloor.
We are planning on installing slate tiles so that is what we were preparing the subfloor for. Our subfloor is tongue and groove 1 1/2 inch planks with a 3/8 or 1/2 inch particle board top.
A friend of mine is a contractor that works for investors that flip homes. He recommended using hardibacker on top of the subfloor. I watched the hardibacker installation video and read the directions. I questioned the use of thinset under the hardibacker to my buddy. He said they never use it and not to worry. He's never led me wrong before so I proceeded to lay down the hardibacker using the recommended screws in the recommended spots. I then proceeded to install our base cabinets on top of the hardibacker.
As our slate should be delivered tomorrow, I began anticipating a weekend of installation. While browsing for some slate sealer, I came across a post describing the use of hardibacker without thinset. There were then repeated posts about how your tile will crack if you do not add the thinset under the hardibacker.
While further looking into the use of hardibacker without thinset, I came across Ditra, which I wish I had seen before.
So, I am fairly certain I will have to remove my base cabinets today, and at a minimum, pull up the hardibacker to at least add thinset under it before putting in back down. I am now wondering if I am going back to square one, maybe I should just opt for Ditra instead and write the cost of the hardibacker off as a learning experience. We are doing the laundry room and a bathroom in the same slate after the kitchen is done so if I switch to Ditra, the labor savings down the road would be significant. My one question is whether thinset will adhere to the leftover paper/felt from the original linoleum that is permanently bonded to my subfloor. Whether I go with re-using the hardi or Ditra, should I cover the leftover linoleum felt with ply to ensure a good bond or will the thinset stick to anything?
Any advice would be appreciated. I hate going backwards but I want the floor to last.