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: 1072

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

Featured Forum Discussions

Too many BTU's. Too much horsepower?

Started by Steve in General Forum. Last reply by Eric Kjelshus 9 hours ago. 4 Replies

Stack/wind pressure and flow networks.

Started by Daniel James Grundy in Training. Last reply by Daniel James Grundy yesterday. 5 Replies

BDT with vermiculite in hollow CMU walls?

Started by Brad Cook in General Forum. Last reply by John Nicholas yesterday. 2 Replies

Strange IR Image

Started by Larry Nissman in General Forum. Last reply by Brad Cook Mar 9. 7 Replies

Videos

  • Add Videos
  • View All

Latest Activity

Eric Kjelshus replied to Steve's discussion Too many BTU's. Too much horsepower?
"Its more about run time with high RH removing, than to large over sized AC unit, in houses.  …"
9 hours ago
Sarah OConnell posted a blog post

Crowdsourcing for Innovation

Share Your Ideas!Novel Building Envelope Design for Increased Thermal PerformanceIn 2014, more than…See More
22 hours ago
Colin de Paor is now a member of Home Energy Pros
yesterday
Walter Ahlgrim replied to Steve's discussion Too many BTU's. Too much horsepower?
"The 5 ton system you have is not 500 hp racecar engines they are 500 hp truck engines. The duct…"
yesterday
Daniel James Grundy replied to Daniel James Grundy's discussion Stack/wind pressure and flow networks.
"So I wanted to start with a basic who can help then go into more detail later. But yes find…"
yesterday
Daniel James Grundy replied to Daniel James Grundy's discussion Stack/wind pressure and flow networks.
"My tutor got back to me and while areas don't quite feel right a little to much assumptions…"
yesterday
Brennan Less replied to Daniel James Grundy's discussion Stack/wind pressure and flow networks.
"Daniel, I'm assuming you're trying to predict the airflows through the different openings…"
yesterday
Martin Newmark 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
yesterday

Home Energy Pros

Welcome to Home Energy Pros – the unique digital community by and for those who work in the home energy performance arena.

Home Energy Pros was founded by the developers of Home Energy Saver Pro (supported by the U.S. Department of Energy) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network. Please honor our Guidelines

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service