DIY Home Improvement Forum banner

insulating attic walls

2K views 5 replies 5 participants last post by  Gary in WA 
#1 ·
I could use some help please. I insulated my attic walls with faced insulation. I was told it was ok to cover the insulation with plastic. I live in North Carolina and worry about moisture under the plastic and onto the insulation. what I am asking is, is it ok to cover the insulation either faced or unfaced with plastic in the hot attic??? I hope someone could give me an accuate answer...Thank you
 
#2 ·
If you installed plastic over a faced insulation you would have 2 vapor barriers. You should never have 2 vapor barriers.
Ron
 
#6 ·
No, do not use plastic yet. We need to know if the wall is an interior with a roof behind or an exterior wall with siding. The siding, sheathing, and wall thickness all pertain.

2nd title here: http://www.ecohomemagazine.com/energy-efficient-design/a-close-look-at-common-energy-claims.aspx

B.S.I. says: http://www.buildingscience.com/docu...sheet-310-vapor-control-layer-recommendations

Vapor retarder or vapor barrier: http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11810

Ask your local B.D. for their ruling. If this area will not be heated and stay an attic, no plastic. If an inside wall with an attic behind it, no plastic but install some house wrap to prevent wind-washing of the wall insulation on the attic side. If the location was South, the vapor barrier would go on the unconditioned side (outside) to keep the humid air out of the wall cavity.

Be safe, Gary
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top