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: 1890

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

Forum Discussions

Investigating 3257KWH monthly usage issue.

Started by Brent Shapiro in General Forum. Last reply by Jason Raddenbach 6 hours ago. 4 Replies

Earn 2 BPI CEUs by Blogging for BPI

Started by Quinn Korzeniecki in General Forum on Monday. 0 Replies

What made this chimney fall down?

Started by Eric Kjelshus in General Forum. Last reply by Eric Kjelshus Jun 15. 5 Replies

Studies on Home Energy Audit Energy Savings Potential?

Started by Julie Saporito in General Forum. Last reply by Danielle Sass Byrnett Jun 15. 5 Replies

Latest Activity

Green ID posted blog posts
14 minutes ago
Rob Buchanan posted a discussion

Building envelope and mechanical interactive effects

Good afternoon everyone,I was reviewing some of the old BPI newsletters and noticed a…See More
3 hours ago
Jason Raddenbach replied to Brent Shapiro's discussion Investigating 3257KWH monthly usage issue.
"Brent, The fridge would be easy to isolate. You can borrow a Kill A Watt Meter from your local…"
6 hours ago
Mick Lane replied to Brent Shapiro's discussion Investigating 3257KWH monthly usage issue.
"My inclination would be to start with the water heater and the refrigerators.  You are looking…"
6 hours ago

Photos

Loading…
  • Add Photos
  • View All

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service