joining plasterboard and cement board / hardiebacker

[penguinlicker]

Good Afternoon,

we're ready to start prepping the wall for tiling. it's in the shower and it's all going to be tiled.

what should you use to join cement and plasterboard together?

ive read that plasterboard is tape and compound and cement board is alkaline tape with thin set (though someone else said tile adhesive) but what do you use for joining them together?

also how do you join the cement board and plasterboard to the ceiling? i don't think the joining tape is there anymore on the wall side anyway.

edit: do I just use the bal waterproofing kit and forget about everything else? It comes with waterproof tape and waterproof coating?

thank you if you can help

 

[Etherglide]

Good Afternoon,

we're ready to start prepping the wall for tiling. it's in the shower and it's all going to be tiled.

what should you use to join cement and plasterboard together?

ive read that plasterboard is tape and compound and cement board is alkaline tape with thin set (though someone else said tile adhesive) but what do you use for joining them together?

also how do you join the cement board and plasterboard to the ceiling? i don't think the joining tape is there anymore on the wall side anyway.

edit: do I just use the bal waterproofing kit and forget about everything else? It comes with waterproof tape and waterproof coating?

thank you if you can help

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[Etherglide]

Am I seeing that correctly? Isn't the board the wrong way round?

 

[mattconway1984]

Why would you want to tape the backer board to the ceiling? Plasterboard tape (scrim tape) is used to ensure you get a nice join between your wall and your ceiling, that helps prevent unsightly cracks.

You should only tape ALL joins that are backerboard to backerboard, using a strong fibreglass based joining tape; this webpage has details (Mesh Tape: Don't skip this step - https://www.diytileguy.com/mesh-tape-dont-skip-this-step/).