I'm wondering if anyone out there has come across specific language for the attachment of fiberglass insulation over an unconditioned crawl space.  I realize there are various ways to accomplish proper installation where the insulation material makes contact with the floor diaphragm.  Personally I prefer to see the use of nylon twine as a means of attachment and I'm wondering if anyone happens to know of any recommended spacing guidelines for the attachment points of a zig zag pattern of twine when used for support of floor insulation.

Views: 4514

Replies are closed for this discussion.

Replies to This Discussion

That all makes sense. Having spent the last 20 years building and remodeling homes and only the last 4 concentrating on building science and weatherization, I am still trying to figure out what many of you veterans have already learned. I thank you for the responses and your time.

See section 3.2 of the ENERGY STAR TERC guidelines

From the "Retrofit Workforce Guidelines" (which are still in critical care & unavailable at the moment - but from my review)

7.36 Accessible Floors (between conditioned & unconditioned space) – personally not the best choice down south, but that’s for another day

  • 7.36.1: Sealing the floor system will be completed before installing – very nicely stated
  • 7.36.2: Insulation will be installed in contact with subfloor without gaps, voids, compressions, misalignments, or wind intrusions & If kraft-faced batts are used, they will be installed with kraft facing to subfloor  - also very nicely stated (though kraft is worse thing you can use)
  • 7.36.3: Batts will be secured with physical fasteners TO ensure insulation remains in contact with subfloor – the only issue is that they also need to minimize compression while still keeping it from sagging

I assume you're aware of the latest Building Science rant from Dr. Joe in which he argues against the requirement that insulation be in contact with subfloor (I excerpt it here at http://homeenergypros.lbl.gov/forum/topics/another-irreverent-whine...), and will try to get this changed in the next IRC code revision.

But why do you say that Kraft facing is a problem? It meets the IRC guideline for a 1 perm vapor retarder.

Thanks Robert & yes I am but that doesn't apply to the here, now or the question posed. 

As for the question about the kraft - no matter where you are at, if one is going to use such a product the last thing you want is water being trapped against it & the subfloor whether it is from moisture in the air, over active cleaners, plumbing leaks, or water splashed from tubs, showers, or sinks. Maybe you guys have less issues up north, but down here unfaced FG is bad enough & the kraft style seemingly just makes it worse

RSS

Forum Discussions

Latest Activity

John Hatfield replied to David Butler's discussion How would you insulate this roof?
"David I think the finish edge application is critical but several un-knows exist. Such as how far…"
8 hours ago
David Butler replied to David Butler's discussion How would you insulate this roof?
"@Kevin, that article is behind a pay wall. Here's the original posted on Allison's…"
9 hours ago
Kevin Miller replied to David Butler's discussion How would you insulate this roof?
"Good question.  I don't know the answer.   I'd love to know whether there…"
9 hours ago
David Butler replied to David Butler's discussion How would you insulate this roof?
"Hi John, thanks for pointing out my faux pas: I made clear in my original post that rainwater…"
9 hours ago
John Hatfield replied to David Butler's discussion How would you insulate this roof?
"Kevin, Is the "Kool Seal" product certified for potable water collection?"
10 hours ago
Mike Berg joined Tom White's group
Thumbnail

Weatherization

Share your concerns and successes as a weatherization professional, or information for this…See More
10 hours ago
Profile IconBlake Reid, James Barras, Kathleen ODonnell and 5 more joined Home Energy Pros Forum
10 hours ago
Jon Finewood joined Diane Chojnowski's group
Thumbnail

Job Board

This group is for posting jobs related to all aspects of the home performance industry including…See More
10 hours ago

Photos

Loading…
  • Add Photos
  • View All

© 2017   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service