Cement board flush with backside of board`

[bmuir]

I am working on a project that requires a piece of cement board rabbeted into the backside of a frame. I want the 1/4-inch cement board to be flush with the backside of the frame. How deep should the rabbet be to account for the construction adhesive used to mount the cement board so it will be flush with the backside of the frame? +1/16 of an inch, +1/32 of an inch, something other than that?
On the same note, how much height will thinset add to the thickness of ceramic tile after it is seated into thinset applied with a 1/4-inch-notched trowel?
Thanks for the help,

Bill

[atgcpaul]

I'll let you figure out the math on the rabbet depth, but in theory a 1/4"
trowel will end up being 1/8" deep after setting tile.

Paul

[just started]

True, in theory, but it will depend on how hard you press on the tile.
Also, I wouldn't rely on adhesive alone to hold the cement board in the frame.