R-49 attic insulation is recommended for this climate, and I spec R-60 for most attic floors because cellulose is cheap.  Yet my own unconditioned attic has an effective R-value of only about 20.  There is a typically settled loose-fill cellulose job from the early 80s under the floorboards.  I decided to relocate the thermal boundary to the top of the loose tongue-and-groove attic floorboards and to the perimeter of the attic floor plane, creating in effect an inverted, insulated box over the living space. I added 2” of extruded polystyrene board and covered it with OSB.  There is no condensing surface inside my inverted box.

 

      I paid special attention to the exterior top plates and (perhaps most importantly) I personally attended to or oversaw every detail.  This led me back to the inescapable truth is that attention to workmanship is the key to building performance

 

 

Views: 95

Comment

You need to be a member of Home Energy Pros to add comments!

Join Home Energy Pros

Comment by Joseph J. Ilacqua on February 23, 2011 at 9:12am
Geez, I wonder who insulated the walls on that house, Chris is taking credit for the attic, my memory isn't quite as sharp as it used to be, i can't remember

Groups

Latest Activity

Gregory Cisco replied to Gregory Cisco's discussion Abandoning under-slab HVAC ductwork which fills with groundwater seasonally.
"We looked into this. Quite expensive and the applicator would not make any guarantees. Looking…"
20 hours ago
Gregory Cisco replied to Gregory Cisco's discussion Abandoning under-slab HVAC ductwork which fills with groundwater seasonally.
"That is what I was thinking. Looking into Flo Fill. Probably using two pours - the first would…"
20 hours ago
Gregory Cisco posted a discussion

Abandoning under-slab HVAC ductwork which fills with groundwater seasonally.

Our company is building a custom home in Wyoming on a site with high ground water. The client…See More
Sep 13
Home Energy Magazine's blog post was featured
Sep 13
Gregory Cisco is now a member of Home Energy Pros
Sep 13
Home Energy Magazine posted a blog post
Sep 12
Building Performance Institute added a discussion to the group Building Performance Institute (BPI)
Sep 12
Sonja Persram replied to Sonja Persram's discussion Energy Savings Guarantee for single family dwellings in cold climate??
"Thanks so much, Andy. Much appreciated. Will em any questions. Best, Sonja"
Sep 11

Photos

Loading…
  • Add Photos
  • View All

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service