Thanks for the tips.

Before putting the backer board on, how much of a floor do you have under it? And what type. I am getting ready to remove my laundry room floor and replace it. I have heard from .75" to 1.25" of plywood or osb over the joists before doing anything else do it. I feel like 1.25" is overkill and will make my floor super high My laundry room is probably only 4x8 or something like that.