I am convinced that a client of mine is the victim of a shoddy crawl space ceiling insulation job, and that he should have it done right. He too in convinced.

So, the question is how best to address it. 

The crawl space is only 200 sf, located below a single-room addition, with ducts in the floor. There are plenty of penetration through the floor and the sill boxes. Air is the least of our worries (it's the darn critters he wants to keep out, and reduced leakage is a bonus). The existing faced fiberglass batts (R-19) are showed into between the joists, with the kraft facing in the wrong direction. The batt insulation is only 5 years old, and it's condition has not been compromised. 

The following is my proposed approach to the problem. Remove the existing batt insulation, apply a flash coat of closed-cell spray foam, cut batts to fit properly, install wire supports to keep batts flush with floor, and install a layer of house wrap to underside of joists to protect batt insulation. Sound like a winner to you pros?

Thanks in advance!

Views: 666

Reply to This

Replies to This Discussion

For the cellulose and rigid I wouldn't worry about the foaming of penetrations unless they are big enough to have a blow out in the living space.

 

For the fiberglass and rigid, I think foaming the perimeter to seal off any leaks would be good, but probably nothing other than that.

Good luck out there.

Thanks, and thank you for your input Cory!

Housewrap as your blowing barrier makes a lot of sense, though it's like wall papering a ceiling getting it in place!!

I dunno about the foam board. Where I come from (cold climate) that might work with unfaced EPS board. But If you use foil-faced Thermax, that leaves you with a vapor retarder on the cold side of the assembly, doesn't it?? Great idea in an A/C-dominant climate. But that's a really bad idea here in Wisconsin.

Don you raise a couple of good points.
As to your points about the rigid foam, the foil facing would be on the cold side, but with Thermax you have foil facing on both sides. Also, I always do all within my power to achieve an effective air seal, which has eliminated any condensation-related issues in the past. Nevertheless, I am going to think further about the points you have raised.
Patrick

RSS

Forum Discussions

Investigating 3257KWH monthly usage issue.

Started by Brent Shapiro in General Forum. Last reply by Joe Konopacki 17 hours ago. 7 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
9 hours ago
Home Energy Magazine's blog post was featured

The Results Are In: These Are The Most Energy-Efficient Utilities in the US

Our first-ever scorecard of US utilities, released today, reveals striking regional differences and…See More
16 hours ago
Joe Konopacki replied to Brent Shapiro's discussion Investigating 3257KWH monthly usage issue.
"Brent, Using an ammeter, I would measure each 'hot' conductor leaving the fuses. (Find an…"
17 hours ago
Chris Allen is now a member of Home Energy Pros
17 hours ago

Photos

Loading…
  • Add Photos
  • View All

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service