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: 4322

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

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Alfie Davis posted a blog post
4 hours ago
Steve Last commented on Tom White's blog post Moving Forward with Home Performance
"Hopefully politicians seeking quick wins for the US economy will see home insulation improvements…"
15 hours ago
Steve Last posted a photo
16 hours ago
Judy Rachel replied to Dean Kirkland 's discussion Im looking for a blower door / duct blaster / manometer rental in So Cal
"You can borrow the equipment from the Tool Lending Library maintained by SoCalEdison.  This is…"
yesterday
Profile IconSteve Last, Paul J Anzalone Jr, Jon Traudt and 1 more joined Home Energy Pros
yesterday
Jamie Medlin replied to angela stanzione's discussion Used Weatherization and auditing equipment for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Please let me know if the flowhood  still for sale. jmedlin@archonenergysolutions.com"
Friday
Jamie Medlin joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
Friday
Laurie DiDonato posted an event
Thumbnail

HERS Rater Training Discount: Register by 1/6/17 and Get $100 Off! at Energize CT Center, North Haven, CT

January 23, 2017 to February 3, 2017
Become a HERS Rater with the NEHERS Alliance!Online Component: January 23rd-February 3rd, 2017 -…See More
Friday

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service