hellow I gutted my bathroom all the wall board and I put up cement backerboard and want to know what I can use on the seams I have the fiberglass mesh tape , Joint compound is for wall board grout is for tile . Cement ? plaster ? I want it waterproof hydrolic cement ?Any help With this I would really appreciate.I'am an electrician not a wall trade and i want it to be right , from the jump. Thanks g, Singh
wow, some of these answers are terrible, I like the one where the guy says dont worry about taping and mudding the seams or the other one that said just double up the backerboard lol. Anyway, you should have a vapor barrier of some sort. Since you already put up the backerboard, you should tape and mud the seams then put a coat of Redgard(made by Custom Building Products, at Home Depot) over the backerboard. You can paint it on, its very easy. As far as the electrical box, if it was dry before then I would leave it as long as its not wrapping around any plumbing pipes.
Cement Backer Board Home Depot
Chicago has it pretty well stated. Use the special cement board tape if thats not what you have. And a regular thin set works fine but I always use a MODIFIED thin set, not one thats scared of you as in mortified .. lol sorry I couldn t resist, You can use a 6 putty knife or just the flat side of the sized trowel that you are doing the tile with. I do it as I go but I can tile a basic shower in 1 day. I d suggest taping it all and let the thin set dry and always check for lumps and bumps in the seams before tiling. As far as water proofing it , its not a bad idea in a well used shower. Use the Red Guard as suggested. Do this after the seams are taped and dry. That way the seams, corners and all is sealed. This is a paint on product. Use a cheap cheap brush because you ll be tossing it. Do a light coat and then let it dry (matter of minutes for the 1 st coat). Then do a 2nd light coat and let that dry 24 hrs. Any questions you can email me through my avatar and check my qualifications there. GL
Remember that when you tile to use 100% silicone in the corners and along the bottom edge before grouting. Let it cure a couple days. This will prevent any grout from getting into those joints. I also used red guard on the seams and joints of the backer board.
