Insulating flat roof with 7" cavity with roof tear-off

Hot-dry climate. Roofer removing all sheathing. Insulating from above while cavity is open. Plan for 5.5" open cell foam to the drywall and also covering dropped soffit area that houses ducts. There will be a minimum air gap of 1.5" (7"-5.5") between the foam and the deck at normal ceiling heights, about 1 ft over dropped ceilings.

Any concerns with this installation? electrical, mechanicals. performance etc?

Views: 1413

Reply to This

Replies to This Discussion

whoa didn't see all the comments until after i posted. sounds like you are on top of things. The OCF is an effective air barrier and will stop most all convective sources of moisture, and I don't believe you need to worry about vapor diffusion in that climate... So leaving the air gap sounds good to me. I'm a cold climate guy so I'd like a second opinion as well. Where's David Butler when you need him?

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Ethan Bukowiec replied to Ethan Bukowiec's discussion Thoughts on energy startup's new propane smart meter
"Anyone interested in learning more about this device should check out the Kickstarter…"
6 hours ago
Linda Wigington replied to Linda Wigington's discussion Low-cost electricity monitoring: Accuracy & Applications in the group 1000 Home Challenge
"Here is a response from Frank Bergamachi (Thousand Home Challenge project #4) I’ve looked…"
12 hours ago
Linda Wigington replied to Linda Wigington's discussion Low-cost electricity monitoring: Accuracy & Applications in the group 1000 Home Challenge
"Here is a response from Larry Kinney A few years ago someone had a gee whiz calibrated watt and…"
12 hours ago
Dale@EnergyWright replied to Linda Wigington's discussion Low-cost electricity monitoring: Accuracy & Applications in the group 1000 Home Challenge
"I've used the efergy Elite whole house energy monitor to evaluate 240V HPWHs. I found the…"
13 hours ago
Profile IconDale@EnergyWright and Maria Lacey joined David Eggleton's group
Thumbnail

1000 Home Challenge

Linda Wigington distinguished between deep retrofits & deep energy reductions, thus expanding…See More
14 hours ago
Profile IconAdam Swain, Cynthia Sandherr, James Skeldon and 2 more joined Home Energy Pros
14 hours ago
Tom White posted videos
22 hours ago
Maria Lacey replied to Linda Wigington's discussion Low-cost electricity monitoring: Accuracy & Applications in the group 1000 Home Challenge
"I attempted to use an AZTech device. I have used the Watt Stopper, Watts Up Pro, Kill-A-Watt…"
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service