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: 1823

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

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Home Energy Magazine's blog post was featured
13 hours ago
Hannah Finch posted a blog post
13 hours ago
Profile Iconpank and Carrie Sturrock joined Home Energy Pros
13 hours ago
tedkidd commented on Amber Vignieri's blog post Chicago Winter No Match for Retrofitted Logan Square Building
"This case study is an example of how hard it is simply to do a compelling case study. Everyone has…"
15 hours ago
B. M. Lubin posted an event
Thumbnail

GPRO Construction Management Class at USGBC-LI headquarters in Hauppauge, NY at USGBC-LI Headquarters

September 19, 2016 at 9am to September 20, 2016 at 2pm
Taught by industry experts using real-life classroom exercises, GPRO CM gives experienced building…See More
19 hours ago
B. M. Lubin is now a member of Home Energy Pros
yesterday
Eric Kjelshus replied to tedkidd's discussion Dear DOE, PACE sucks - please fix or make it go away...
"Most HVAC system upgrade - change outs and attic seals-R-49 end up $20-30K   Most house -…"
yesterday
Brennan Less replied to Rob Madden, Solar Home Broker's discussion Indoor Air Quality Monitors and Meters
"Anyone interested in this realm should check out the EPA-funded project at the South Coast Air…"
yesterday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service