Taping and tanking backer board (and niche)

[mwebber]

Hi,
I’ve spent hours trawling through previous posts, here and elsewhere, about taping and tanking backer boards and I’m left feeling a bit bamboozled. Different products, different combinations of products, different contexts, different opinions…

Builders have done the shower room in a new loft conversion and I’m now doing the tiling myself. They’ve fitted 12mm hardibacker and built a custom niche from the same.

My current plan is just to buy the mapei tanking kit: prime everything, gum the tape on to all joints and corners, then tank. I may buy the preformed corner-tape section or may just work it out myself.

Does that sound right? Or do I need to use a sealant product (CT1 perhaps) on the joints before applying the gum and tape? I saw someone use scrim and mortar and then apply the tanking tape but that just seems excessive!

Thanks!

 

[simplesteve]

Your first ‘version’ is correct - Buy the tanking kit, paint it on. Use the tape that comes with it to go over the seams/joins. No need for any preformed corners or CT1 etc.

 

[yorksbuilder]

buy the mapei tanking kit: prime everything, gum the tape on to all joints and corners, then tank

Yes correct

 

[drives]

When I've done ours I've used the hardiebacker tape and then trowelled on some tile adhesive over the joints as you say.

I've not used the Mapei one. I tried the Everbuild kit which I thought was rubbish. I can certainly recommend this one though and it comes with two corner pieces.

https://www.protilertools.co.uk/product/tilemaster-tanking-kit-waterproofing-tub

Use the paste and then apply the tape/corner pieces, then you can go over them again and apply everywhere else. I've always done a small overlap with the tape at the bottom, over the tray edge.