Replies

1. 
   rdesigns | Jan 05, 2010 03:37pm | #1

   no

2. 
   calvin | Jan 05, 2010 04:29pm | #2

   I'm about to install a
   I'm about to install a one-piece shower unit in my master bath. Exterior walls have been spray-foam insulated. Do I need to install anything between the unit and the studs?

   No, but you may have to pack out the studs around the unit to compensate for the flanges. If they're real thin, you might be able to backcut the drywall or "float it" over the flanges.

   Strips of cardbd, 1/4''ply or wood lath work.

1. 
   Matt | Jan 05, 2010 06:16pm | #3

   Calvin:

   The way we do it here is end the drywall just short of the flange. This results in a pretty good sized gap over the flange that they will with durabond or another brand of setting compound. It seems to work pretty well. Been doing it like that for about 5 years. The only caveat is that you need to be sure there are nailers around the flanges for attaching the drywall to Which isn't a big deal. I just have the framers turn a (straight) stud flat-wise to catch both the tub and the edge of the drywall.

1. 
   calvin | Jan 05, 2010 06:57pm | #5

   Submitted by Matt on Tue, 01/05/2010 - 18:16.

   Matt, I've done that b/4 and to be honest......didn't mention it because tho it works, it was a bit of dicking around. The mud sags even when applied pretty stiff, Then you have to flat tape it. Not for a novice for sure.

   But it does work and eliminates furring a whole wall out away from the surround.

   Thank you for keeping me honest.

1. 
   Matt | Jan 05, 2010 09:57pm | #6

   Cal - yea, and when they put the mud on that thick ti takes forever to dry - even when using - say 30 min - durabond.

   We used to do it the other way where the sheetrock was (supposed to be) back cut for the flange, but it never seemed to happen right and then other problems resulted. You are right - furring out the surrounding wall would be a fool proof method for a novise (sp?).

   BTW - I like using moisture and/or mold resistant drywall at this location. The upcharge is minimal.

1. 
   calvin | Jan 05, 2010 10:21pm | #7

   If it was easy............

   Speaking of easy, It shows I didn't read any of these 6 or 7 posts in this thread either.

   Man, wasted my time with this carpentry. Should have packed up all those punched cards back in 64 and did something with myself.

3. 
   Matt | Jan 05, 2010 06:25pm | #4

   Bill:

   It sounds like you have it covered, but when you have a gap behind the tub like that it is very important to be sure there is no air leakage from outside to in. The reason being that if there is exterior air leakage then the whole tub will be cold and your pipes could be subject to freezing.

   Others reading this are probably thinking - WTF - there is always a big gap behind one piece shower or tub-shower units. When building Energy Star they have us cover the insulated wall with a substraight before installing the tub/shower unit. The substraight might be something like thermaply (cardboard sheathing) or similar and tape/caulk the joints and edges to prevent leaking cold air from circulating around the tub. Another material I have used for this is a product called Ramboard which is a roll cardboard that is meant to be used as a floor covering. Again though, the foam should take care of any air leakage.

4. 
   PatchogPhil | Jan 06, 2010 12:51am | #8

   If you have any interior walls behind the 3 sides of the one piece unit, consider stuffing some soundproofing insulation like Roxul rockwool behind and under it. Drastically cuts down on the drumming sounds from the water hitting the walls/floor.