Installing Hardibacker board
I'd like to install a ceramic tile floor in my kitchen. I ripped up the old floor and now have a 3/4" plywood sub-floor over the floor beams. I'd like to use Hardibacker board as the ceramic floor substate. I went to a tile store and the salesman told me that I can attach 1/2" hardibacker board directly to the 3/4" subfloor bringing me up to what he said was the minimum floor depth of 1-1/4" to install ceramic tile on. He also said I do not need to put the use both thinset and screws to install the hardibacker. He said I only need to use liquid nails and screws. Can you please tell me what to do because I see lots of conflicting information on the forums. Do I need to install ANOTHER layer of plywood before I install the hardibacker? If yes, what thickness do I need to use?