I have an old house that's built on pillars and has shifted a little over time. We are remodeling the kitchen and just ripped up many layers of creatively installed flooring. We are down to the bottom layer of plywood and it dips on one side of the room (8"x 15" room) and then kind of comes back up.
We aren't sure how to tell how sloped it is or how much leveling is really necessary. We have heard that if we don't level it the tiles will eventually crack so we want to prevent that.
We are planning on putting down backer board in between the plywood and the tiles, will that be enough support or is it important to do some sort of leveling first? If we level with something like cement will we need another layer of plywood or can we put the backer board right on top?
Any advice appreciated, thanks so much!