Another quesstion. When the bcu meets the ceiling what do you use to seal the joint. (Tile will be going to the ceiling) do I use a)fibermess and thinset b) fibermesh and drywall compound or c) caulk ( and what kind). Thanks

There's really no benefit to sealing the joint between the CBU and the ceiling, although you can if you want. I usually just tile up to about 1/8" from the ceiling, then caulk the tile to the ceiling with painter's caulk. It can then be painted to match the ceiling. Alternately, you can use color-matched grout caulk.

You know I think I'll go that route. Pittsburg corning also offers a spacer system that could work for me. The ceiling below the shower is accessable so i decided to reinforce between the floor joist so it can handle the weight, is this overkill? I will caulk above the tile where it will meet the ceiling. But a side note now, how do you seal the joint where drywall and bcu meet along the same wall?

Since tile goes over that joint, treat it just as you would any other CBU joint. Mesh and thinset.

hey ive been on this web site for a hot minute and forgive me if i am violating some discussion protocol but i am in need of a little direction. i am installing a 6 x 4 shower in my basement. i have put in the mud deck and have installed the membrane liner with the intention of installing a vapor barrier and hardi backer board then tile.
however i have been reading a lot of comments about the kerdi membrane over regular drywall or greenboard instead of the durock or hardi backer board. so to get to my question is it advisable or applicable to install the kerdi membrane over a "normal " drain or should i just continue in the direction that i am going.

The above post now has it's own thread. (kerdi membrane or normal liner)
Please go there to leave any comments.
Thank-you

Ok, I have another question or just Clarity. When building the shower pan the instruction say the first layer is to be a mortar mix. Can this be a premixed (store bought) or sand and portland mix. Secondly the layer above the shower pan liner the instructions say 4 parts sand and 1 part portland. I do understand the consistencies of water content or additives wet vs dry vs crumbly. The issue is using the right stuff. Oh Sorry about starting a new thread.

Ok, I have another question or just Clarity. When building the shower pan the instruction say the first layer is to be a mortar mix. Can this be a premixed (store bought) or sand and portland mix. Secondly the layer above the shower pan liner the instructions say 4 parts sand and 1 part portland. I do understand the consistencies of water content or additives wet vs dry vs crumbly. The issue is using the right stuff. Oh Sorry about starting a new thread.

Prepackaged sand mix is a little on the rich side and should have a little more sand added to it. You might just as well make your own with construction or masonry sand and normal portland. Ratio for both layers is 4 to 1 or 5 to 1 and just enough water to make a ball in your hand without leaving your hand wet.

I thought so Thanks