Need help waterproofing plastic tile ready shower niche

[mfran12345]

Hi. I'm tiling my shower with 3x6 subway with a shampoo niche in the wall. I got a plastic niche you can apply tile directly to from the tile shop. It has 1/2" thick and 1/2" wide flanges on it so the hardi backboard on the walls is flush with the niche. I left a 1/8" gap between the niche and the cement board just like the joints where two cement boards meet. Sorry I don't have a picture. But anyway I'm going to be taping the cement board seams and I'm wondering what I do at the shower niche seam. Afterwards I'll be applying redgard as my waterproofing. How do I fill in the seam between the niche and the cement board, just like the cement board seams with mesh tape and then thinset? And then how do I apply the waterproofing. On the walls and over the entire niche?

Also what's the proper technique for doing the cement board seams. Thinset into the joint and troweled smooth, then apply mesh tape, then more thinset on top of tape? Or just tape over the joint and thinset on top of tape. Thanks

 

[Dj2]

Use mesh for the corners.
Go to youtube and search tilemasterga - he has good tips, while demonstrating.
Also go to bridgetileforum.

 

[Sponsor]

 

[mfran12345]

Thanks

 

[Jadnashua]

Treat those seams just like any of the other cbu board seams...alkali resistant mesh tape and thinset. Ensure you let that cure before coating with RedGard, or whatever paint on waterproofing you choose.