# cheap great stuff foam insulation powers?



## Mike Finley (Apr 28, 2004)

I hate to do it, but I have to have run a hand sprayer line to the exterior wall of a shower, the interior wall just won't have any room, so the only choice is putting in on an exterior wall.

The mixing valve will be on the interior wall and just a single pipe will run to the hand sprayer shower el. Probably no more than 20-30 inches of line in this exterior wall. Besides insulating it (2x6 wall) with batts, I was wondering if there was any benefit to incasing it in some great stuff or similar expanding foam out of a can? I guess I could read the side of a can and see if they say it has any insulating powers or not, but figured I'd ask here first see what everybody else thinks.

Couldn't hurt, won't do a damn thing, should help a lot?


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## Snobnd (Jul 1, 2008)

Can you run it thru the ceiling?? another inside side wall? If no other option do you like using Pex? JMO


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## Kent Whitten (Mar 24, 2006)

A piece of rigid insulation board should work. Cut it about 1/4" shy and spray foam the crack.


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## rex (Jul 2, 2007)

is it under full pressure all the time?

meh forget it...id let your plumber finger that one out...tell your plumber to have the HO sign a waiver

why dosent your plumber (if possible) and not under constant pressure run it thru the attic with pitch so it drains out

thats what I as a plumber do with rain heads or handhelds...

can you fir the wall out a bit so your plumber can rough it in there?


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## KillerToiletSpider (May 27, 2007)

Make sure you pitch the line towards the hand shower to allow as much water as possible to drain out when it is not in use.


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## SLSTech (Sep 13, 2008)

Insulate that section with rigid foam like Kent said & spray the cracks - that will give you more insulation and eliminate any air infiltration issues which is the biggest cause of freezing lines. Pex is also a good choice do to its ability to handle the expansion better if it starts freezing.


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## Mike Finley (Apr 28, 2004)

I was just curious and looking for anybodies expeiences with this stuff used this way.

I looked into it more last night, seems that great stuff is polystyrene, the same thing as ridgid insulation like EPS or XPS. So the R-value should theoretically be the same.

I was hoping that this stuff had much higher R-values, more like polyurethane like whats used in some SIP panels with R-values 20% higher then rigid foam.

The Dow site doesn't recommend doing any of this, they state curing issues with too thick of applications.

I like the idea of using gravity on your side to drain the line as much as possible, very good thinking right there! :thumbsup:

We shouldn't have to run it through the ceiling, should be able to run it up higher in the interior wall with slope to the corner and continue the slope in the exterior wall to the EL right? The interior wall is 120 inches tall and then I don't believe there is attic above this space, just a cathedral insulated ceiling.


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## TimelessQuality (Sep 23, 2007)

I'd use that great stuffrolleyes to insulate the wall cavity from the sheathing to the pipe. 

Then leave the piping exposed in an air pocket to the warm side...:thumbsup:


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## wyoming 1 (May 7, 2008)

Mike we have had good luck placing a piece of foil bubble insullation between the pipe and the regular insullation.


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## Mike's Plumbing (Jul 19, 2010)

I had a job once where one lavatory line was on an outside wall. It kept freezing but not bursting. I drilled a 2" hole in the floor plate on the wall so warm air would work it's way in. That was 3 years ago and I know the family very well, it hasn't froze since. We even joke about it every time we talk plumbing because they have insulated the piss out of it and the hole is what ended up working. Check it out and see if that's possible. All you need is a little warm air to mix and will never freeze.

I haven't seen you on the forum in a while Mike, hope all is well with you.

Mike


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## JohnFRWhipple (Oct 20, 2009)

*Spray Foam for shower feeds*

Mike we have done this before. The feed to the shower head is not under constant pressure and will be fine if it's sealed off from the air draft. We make up a box out of rigid insulation to contain the spray foam and then shoot away.

The only pipes I have seen freeze on an exterior wall have done so because of air drafts. Wrapping the pipe with a foam sleeve and covering it with foam stops any condensation on the pipe and elimates the chance of air flow over the pipe.

You may create air flow issues by solid blocking the stud bay an may need to keep the rigid insulation off the back side of the sheathing some.

JW


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## Plumbing Zombie (Jun 11, 2011)

Wow the things you guys get away with lol! The ahjs around here would never let that fly no matter what. Maybe you could install a vacuum breaker in line on the interior wall with an anti-siphon and drain to basement laundry tub? Then there would be no chance of any water in the line at all and no chance of back siphoning from the vacuum break drain. Of course you could always tap a heat run and build a ductboard cavity around it. Fyi I'm Buffalo, NY area.


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