No thinset below Hardie Backer
I installed 1800 sf of 1/2" Hardie backer, I first used self leveler in many area's to eliminate uneven surfaces. I then screwed the backer board down every six inches over the self leveler and 3/4" plywood. I was unable to put thinset down because it would have prohibited me from opening entrance doors throughout the house (the tile was thicker 5/16 of an inch). I have been told that the tile or the grout joints will crack. I also installed expansion joints at numerous locations. What is your take on this?
Thank you