I wanted to know if anyone had any experiences using the bubble wrap w/ the double sided radiant barrier.

I had a weird experience thanks to a fire pit, my Brother-in-Law, and a few beers.  My Brother-in-Law made a make shift pot holder looking glove and held it about 8" away from a pile of extremely hot embers.  After nearly a minute the glove started to smoke because the exterior nearest the fire was starting to melt.  Despite this, he said the inside never got that hot.

What I am figuring is that, if this material works this well with such extreme temperatures, why wouldn't it be useful in a knee wall area?  It would be a lot easier to install than rigid foam board and much easier to squeeze through a small access hole.

 

What do you guys think?  Do you have experience using this material? (Keep in mind I live in Atlanta, GA, not New England).  Thanks!

Tags: Insulation, bubble, heat, knee, transfer, walls, wrap

Views: 991

Reply to This

Replies to This Discussion

Remember, a radiant barrier only reflects radiant heat.  The fire test your brother in law did was the ideal test for that material, since essentially all the heat was radiant, but in an attic situation that's not the case.  For the radiant barrier to work, there has to be an air space between the barrier and any other objects (to rule out conduction), and its surface has to remain clean and shiny (no dust collection).  So would it help in a kneewall area?  Maybe a little, but not as a replacement for insulation.
I get your point, but I am talking about using it in addition to the existing insulation.  The most common treatment here for knee wall problems is to seal the penetrations from the attic side of the wall, push the batts (usually R-13 here) back into place and then attach Thermax sheathing with a radiant barrier to the studs over the batts and seal the seams. Sometimes the construction, access, and penetrations make using a rigid foam board product very difficult to use. The bubble wrap radiant barrier seems to be a good alternative.

Installed in that location -- over the fiberglass batts -- I would be concerned about condensation on the bottom surface wicking into the fiberglass and creating mold habitat.  I'd also be concerned that dust would accumulate on the top surface and make the radiant properties useless. 

Has this stuff been in use long enough to be able to check in on an installation that's 5 or 10 years old to see how it's holding up?

Jon,

 

  I'm guessing that the foil/bubble wrap will provide a real good air seal if installed properly (like every other air seal material) but will be much more costly than poly wrap and not provide anywhere near the insulation of EPS or XPS board.  I've seen no independent testing of these products to verify their claimed "R" values.  Knee walls are always a pain; almost makes you want to rip out the walls to re-do everything.

You can say that again.
We see Reflectix used behind knee walls all the time.  It is the air barrier to prevent windwashing, and meets code for fiberglass batt covering.

You should put a link to Reflectix in your post. I haven't heard of it.

RSS

Videos

  • Add Videos
  • View All

Twitter

Latest Activity

Chris Laumer-Giddens posted a blog post

Building with Rocks, Rocks. Check out the Drying Potential

Building with Rocks, Rocks! Check out the Drying Potential.Check this out! This 24" x 48" x 2"…See More
1 hour ago
Evan Mills's blog post was featured

Looking Back and Looking Forward: Home Energy Pros at 5 and 5000

Over the past five years, the Home Energy Pros social network has grown from a twinkle in our eyes…See More
7 hours ago
Profile IconJACK and Noah Ray Sanders joined Home Energy Pros
7 hours ago
Eve Dunham joined Diane Chojnowski's group
Thumbnail

News & Announcements

Share your news and announcements with the community in this group.To post news or an announcement,…See More
8 hours ago
Eve Dunham joined Tom White's group
Thumbnail

Weatherization

Share your concerns and successes as a weatherization professional, or information for this…See More
8 hours ago
Eve Dunham 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
8 hours ago
Eve Dunham joined James Sayers's group
Thumbnail

Marketing Energy Efficiency

Sharing ideas, tools and examples of promoting energy efficiency to consumersSee More
8 hours ago
Eve Dunham joined A. Tamasin Sterner's group
Thumbnail

Dear Occupant:

What conditions were present when a customer had an Aha moment?  What made the communication…See More
8 hours ago

© 2016   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service