Newb needs help with custom shower

[Bert]

Hi

I guess I should have found this board before but I'm glad I found you now

Here is where I'm at with my custom shower.
size is 5x6ft with a slopeing roof about 8ft down to 6ft, 2nd floor new construction, 11 7/8 joists with t&g plywood floor, walls and cielings done in greenboard.
I had a freind of a friend do the floor and as far as I know he does these professionally.
after reading the board, Im sort of concerned.
He installed a membrane colled "compu" somethingorother. looks like a blue sheet membrane. Installed about 10 inches up the green board in one piece. It is installed on the clean plywood then put in a mortar floor pretty thick maybe 3"-4" thick with a slope. the membrane is is caulked and screwed to a drain with a seperate place for the membrane and a screw in drain.

Question
1- is the membrane supossed to have mortar under it for a slope?
2- he says use wonderboard on the walls and ceiling and dont use screws below 6 inches .
3- am I supossed to tape and seal the wonderboard before tileing.
Maybe a few more ?'s
Thanks Bert

1)There sould be a preslope about 1/4" per foot under the membrane to allow water to drain over to the weep holes in your drain assembly, providing he didn't block them up with his mortar bed, otherwise, water will just sit in the pan and not be dirested to the drain.
2)Wonder board over green board? You should have brought the pan liner up over the studs with a moisture barrier overlapping the liner and installed 1/2" wonder board to the studs. Cement boards do not water proof, they just provide more stable backing and donot deteriorate when exposed to water. Water can reach the green board through the cement board and start to break it down, especcially wher the surface has been breached by screws.
3)Fill the gaps between boards as you tile with modified thinset and embed alkalie resistant mesh tape over the seams as you tile to prevent a lippage causing bulge wher the seam was taped.
4)You didn't ask a 4, but yes, I'd address the no preslope issue and green borad issue before you proceed the ensure a problem free shower.

"Saving the world from premixed thinset one customer at a time"

[Jason_Butler]

Unregistered is correct on all points. I have attached the link to the membrane you mentioned. It is an acceptable liner when done correctly. The drain is usually where the membrane is comprosmised. Was it leak tested before the setting bed was poured?

http://www.compotite.com/compgold.html

Jason

Wow, look at all my spelling errors. I should proof read in the future. I wasn't trying to write in Texan.

"Saving the world from premixed thinset one customer at a time"

[Bert]

"Wow, look at all my spelling errors"
I dont think I have room to talk.


So are you saying this will not work and I should start over before I screw up the whole project. I didnt watch him but dont believe he did anything to keep weep holes free. I know that the drain is screwed to the floor and there is at least a 1/8 inch rise of the membrane to get to the drain?

"Wonder board over green board? You should have brought the pan liner up over the studs with a moisture barrier overlapping the liner and installed 1/2" wonder board to the studs."
I should take the greenboard off, bring the membrane up the studs a few inches line the walls with plastic down over the membrane then use wonderboard? also a vapor barrier on the ceiling? I plan on tileing that also.
Thank you
Bert

[John Bridge]

Hey, hey! Watch those Texan remarks. We spel jus find around here.

And get registered or get logged in. We need to know who you are.

Hi Bert,

I have to go along with the rest here. You could break the mortar out of the floor right now and if you're careful you won't damage the liner. But even if you do it can be repaired.

It IS okay to have the green board on the walls, though. It should be cut up to where the pan ends, and the pan should go back to the studs and backing blocks. You can then intall a vapor barrier over the greenrock and then the cement board. There is little chance of the greenboard getting wet if installed in this manner.

[Bert]

is plastic sheething ok for a vaper barrier and should I do the ceiling also?
Thank you and thank you for all the response
Bert

[John Bridge]

4 mil or 6 mil plastic sheeting is fine. There will be nail holes through it, but they are insignificant. Don't put anything on the ceiling. The ceiling tiles can be set directly to the drywall. No water ever gets up there.

[cx]

Yep, what John said about cutting the greenboard away to the top of the pan liner, hanging a moisture barrier and CBU. That's the way we been doing mud showers for lots of years. I'd be sure to pewt big ol' dollops of thinset or even some fat mud behind that CBU at the bottom because you'll have such a big gap there. Not a problem with mud walls, but you ain't got no mud walls, eh?

Also what John said about our friend "Unregistered" gettin' him/herownself registered. I've mentioned it twice before, which I think should be sufficient. We welcome the help, but we need to know who's dispensing advice here in the DIY forum. Thanks.

[Bert]

What's a CBU? Concrete wallboard. and how do I keep the membrane up between the studs?

30000 posts! WOW

Bert