I am in the middle of a project to tile my kitchen. I have removed the vinyl flooring and sanded the plywood so that it is perfectly level. My plan is to lay down the tile on the plywood given what I found.... when I looked at the flooring already laid down there is 3/4" plywood on the joist, cement board on top of that, and 1/2" plywood on top of that. I know that I need to protect against deflection, but how much more support is another layer going to add to my project.
Isn't there already enough down to prevent deflection? Or is there another concern that I am not considering?
the house was built in the mid 90's.