# Water pipes behind basement insulation



## ariapn (Mar 29, 2010)

Hi, I'm a complete newbie trying to finish my basement. I'm attaching a picture of my basement wall. I don't know what to do with the water pipes running in the middle of the wall. If I move the frame and insulation forward, putting the pipes behind, do I risk having the water freeze during the winter? I live in central Illinois.
Thank you.


----------



## Snav (Aug 20, 2009)

Ok, what exactly are you doing? Are you building a wood wall over top of your brick and then actually finishing the wall off with drywall? Or are you just putting up insulation?

Insulation should always go behind pipes if the pipe is within a wall for a few reasons - #1, if the pipe ruptures you don't want it hiding behind insulation which would slow down a speedy repair or even hide a leak, which would invite a lot of water damage. #2, PVC sometimes becomes more brittle with cold - it's rare, though, that drain pipes burst because the water inside isn't under pressure (and this is a drain pipe - see the cleanout cap on the right? That's so you can clear out of a clog from the line). Water-lines (hot and cold) burst when the water inside freezes and the pipe cannot expand with the ice - and it ruptures.
There should be some type of access to the pipe (at least the area of the pipe that has the cleanout cap) so you can maintain as is necessary. If you're putting up drywall you can buy an access-door for this purpose, just be sure there is enough room for someone to actually get access to the cleanout cap through the entry.


----------



## Scuba_Dave (Jan 16, 2009)

I would put 1/2" rigid foam against the brick if possible
Then re-attach the pipe hangers
Then build the wall to encase the pipes
Put insulation in but not in front of the pipes
As stated make sure you put in an access panel for the cleanout

Is your basement damp ?
Has there ever been water in there due to heavy rains or floods ?
IE - the past 20 years ?
Recent heavy rains here many people have had water in their basements that never had it before

Our basement will only be finished with material that can't be damaged by water


----------



## ariapn (Mar 29, 2010)

Ideally, if I don't have the pipes, I would like to put up frame directly against the wall and then install insulation.
The house is about 5 years old with no history of water in the basement. The basement is pretty dry.
Is rigid foam enough insulation or do I need more?
So the sequence should be concrete wall - rigid foam - pipes - frame + insulation - dry wall? I'll have access to the clean out cap.
Thanks.


----------



## Scuba_Dave (Jan 16, 2009)

Reg wood & fiberglass can't be in contact with cement walls
Water Vaper can still come thru & can lead to problems

2" rigid will be about R10 which may be enough
But usually energy guides require R13 ?

Rigid then the pipes ..not sure how big the pipes are, pic not showing up now
So possibly build the wall above & below the pipes so that the drywall will cover the pipes
Then insulate w/R13 above & blow the pipes
But not in front of the pipes - towards the warm room


----------



## bjbatlanta (Jul 16, 2008)

I'm with Snav, though I'm not an expert in this area (might try posting on the plumbing forum). It's highly unlikely a drain line (especially a large one) would freeze up as there's not standing water in it, provided the slope is correct. And from the looks of your egress window, the line is actually below grade. so even less likely to freeze.


----------



## Gary in WA (Mar 11, 2009)

I'd move the pipe out from the wall by cutting in two places- one on the ceiling horizontal just before the elbow 90*, and one on the vertical section to lift the long horizontal for proper pitch (judging from the horizontal panel grout lines), use Furncos if you don't like glue. Also research this: http://www.buildingscience.com/docu...rol-for-new-residential-buildings?full_view=1

And change your rim insulation: http://www.rd.com/57548/article57548.html


Hope you have egress by another larger window to meet minimum safety code: http://docs.google.com/viewer?a=v&q...y1T18k&sig=AHIEtbSRVIXJq_EANqct01YzyGnQ8v_t9g


Be safe, Gary


----------

