Do I need to put down hardie- backer under a membrane shower pan?It has 2 layers of 3/4 inch plywood on the floor. Wont 2 layers of 30# felt do.
Where the 1/2 backer board meets the 1/2 green board,…I made the joint just inside the shower stall line so that the backer board is’nt visible, and the tile will over lay that joint. Mortar and mesh tape.? Also, where the backer meets the drywall ceiling,..mortar or drywalll mud? Tile goes all the way up. I am so used to using green board that these details I don’t know about.
Replies
backer boars where it'll get wet. Backerboard mesh tape and thinset on those seams. I do the same at the ceiling line. I'd rather have thinset than joint compound anywhere near the water.
I don't use backerboard on the floors.....as my pans are all site formed mud pans.
They get felt over the ply....if the contractor remembered.....if not..the dry pack mud get's slapped right down at the proper slope. Then the rubber membrane and drain assembly...then the diamond mesh...then an even layer of dry pack mud.
The backer on the walls is applied over plastic sheeting...with the backer about 4 to 6 inches short of the floor.....the plastic running all the way down. The idea is to have the floor pan shaped to run up the floor......rubber/wire/mud....everything.
Float out the wall/floor joint to the same thinkness as the walls....and as straight and square to the floor as possible.....make for a much neater looking...and more waterproof....tile joint.
All the flat's get grouted...all joints at angles get grout caulked. Joint to ceiling board get caulked......edge of bullnosed tile get's caulked by the painter......Dave just prefers it that way......or I'll grout caulk and he'll split the line.
The thinset can be mixed a little thinner if need be for the backer/DW joints.....if the joints work out..the tile should cover.....and at the ceiling...I've been pretty good at feathering the thinset where it's not a problem when painted.
Jeff
Buck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite