scratching my head on best way to do shower

[paul21]

hi all,
awesome site and thanks for helping us DIYers. i plan on redgarding entire shower or maybe not the floor depending on your answer
i completed the preslope with chicken wire and its just under 1/2 inch thick at the drain, but havent installed the cement board walls yet or applied any redgard yet. i did put plastic sheeting under the preslope to keep the moisture from the preslope mud being soaked by the subfloor. i also have an outside wall with vapor barrier over insulation. i was planning on doing the traditional pvc liner when someone told me about the divot method which led me to question best method now.
1. custom building products told me that redgarding the outside wall which already has the vapor barrier will not cause any issues with mold (mold sandwich) whats your thoughts?
2. is the plastic sheeting under the preslope any concern for a mold sandwich when the pvc liner or redgard is applied over the preslope?
3. do you recommend the divot method over the pvc liner? if so, can i just add the additional layer of mud on top of the preslope and use a bonding agent in the mix instead of water? if not, i can rip out the preslope and start over.
4. when i install the cement board walls, is it ok to sit them on top of the pan since it will be redgarded down and over the floor, with 6" membrane fabric?
thanks again
5. if i just use redgard and not pvc liner then it would be easier over the curb as i could install cement board there too and redgard. if i do pvc liner over curb, whats best way to secure cement board to the curb over the liner?
6. should i scrap the redgard and pvc idea and do a sheet membrane like kerdi on the floor/curb up to the walls with a membrane fabric transition with redgard up the walls?
thanks

[Carbidetooth]

0. Chicken wire isn't an ideal choice here. Expanded metal lath mo' betta.

1. Need to distinguish between "mold" and "moisture". Moisture can lead to mold, but the reverse is not true. Regardless of Custom's advice, I'd probably slash up the vapor barrier a little. Your geographic location carries some weight here. It has to do with a phenomenon called vapor drive.

2. No

3. Do you mean instead of or in addition to? You're talking about different methods of moisture control. Topical vs. traditional mortar bed and liner. Pick one, implement meticulously and be happy. Both work. Chevy or Ford or Toyota? Chocolate or vanilla? I like topical sheet membranes FWIW.

4. Depends on method chosen. If using Redgard, theory would suggest embedding in first and only slope. Different for traditional shower liner with preslope and upper mortar bed. I wouldn't want to depend on fabric and Redgard alone to prevent deflection of Durock between studs.

5.Can't do the latter successfully IMHO. Liner requires building curb with fat mud and lath. Any penetrations of liner, inside or on top of curb, compromise its functionality.

6. I would, but one size does not fit all. And no amount of mix and match makes up for less-than-good craftsmanship. One method, done well, warm fuzzies all around.

[cx]

Welcome, Paul.

What Peter said.

The only thing I'd add is that I would personally not use any liquid-applied direct bonded waterproofing membrane (ANSI A118.10) to make a shower receptor. Sheet membrane, yes. Liquid membrane, no. But it's done alla time.

My opinion; worth price charged.