# Insulating tight space under low slope roof



## jamieofansa (Feb 25, 2010)

My master bedroom is part of an addition and I'm having troubles coming up with a game plan to insulate it. I'm in northern NJ.

I had the leaky roof replaced with a few portions of drywall ripped off due to water damage and a removed skylight. The roof is a slope roof that comes off the back of the original A frame roof. As I expected the addition was done unprofessionally and thus has no insulation, randomly spaced 2x4's (between 10" and 18"), and there is unsecured wiring laying across the wood. The space is 3' at the tallest tapering down to 1' or less.

I think the best option will be to use blown in insulation via the existing openings in the drywall ceiling. I imagine shimmying up there and insulating from the edges back to the access hole. I'll build up a wood barrier there to keep the blown in from coming down then hop down use fiberglass batt for access section. Then drywall it shut and never worry about it again.

If you have a better idea that's not unaffordable sprayfoam please share.

Questions:
1) Do I need to worry about a vapor barrier under the blown-in? 
2) If I blow in all the way up to the roof on the shallow ends, will I have problems with ice damming, condensation, or anything else? I don't believe there is any ventilation.
3) I know blown in settles, what height/R value should I get it to before sealing it up forever?
4) What, if anything, should I do with the wires while I'm up there? There's lot of slack, they just installed the electrical and everything as is.


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## joecaption (Nov 30, 2011)

Can you post a picture.
That roof is a mess. Not likly to hold up for long built like that and that low a slope.
Look up SIP roofing panels on the net.


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## jamieofansa (Feb 25, 2010)

Can't imagine how a picture would help illustrate to be honest.

As far as not holding up, I recently had it reroofed by a well respected contractor and they had no problems with the angle, structure, etc. There are many roofs with the similar angles or completely flat as is common in urban areas.

I think you may have misunderstood in my assessment of randomly spaced 2x4's due to my own vagueness. It looks like the roof structure and walls were done correctly and are spaced as expected. It is the ceiling framing and electrical that are not as expected.


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## Windows on Wash (Aug 30, 2011)

Anything that narrows to 1" is really tough.

If you dense pack the area, you will at least eliminate air movement but it will not account for the terribly inadequate R-Value in that assembly.

Is it vented at all?


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## jamieofansa (Feb 25, 2010)

Hi, it goes down to about 1', not 1". There is no venting.


Still really not sure about vapor barriers, do I need to get one down before I lay the blown in?


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## Windows on Wash (Aug 30, 2011)

Which part are you in...?

http://energycode.pnl.gov/EnergyCodeReqs/?state=New Jersey


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## jamieofansa (Feb 25, 2010)

I am in climate zone 5


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## Gary in WA (Mar 11, 2009)

I believe any wires on the joists within 6' of the AA have to be covered against someone stepping on. Cellulose or f.g. without ventilation in a low attic or cathedral is risky; http://www.buildingscience.com/docu...archterm=attic+fiberglass+batts+in+flat+attic

Gary


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