I have read everywhere that you need to have at least 1 1/8" or more thickness of plywood in order to tile it. My problem is, when we removed the old tiles, we found that they had been set on only 3/4" plywood. Since this is an entry way, I have to worry about the door opening and closing if I change the height. To be honest the idea of tearing out all of the plywood does not sound appealing, but I want the floor to be done correctly.
Since I have also read that you can't install Hardi-back directly onto the floor joists, what should I do to keep lowest height? Can I use 1/4" ply (I can't even recall seeing any) and then 1/2" Hardi-back?
This project is for a 50 sq. ft. entry way with one step and a six inch riser. As far as we have been able to tell, the joists are every 16 inches.
How is it that the original installer was able to get good adhesion in 1972, but in 2002 I have all of these other issues? Shouldn't technology be advancing instead of going backwards?
Thank you for your help. If only I could wave my ponytail and have the ugly old tile back and not have to worry about this issue!