Prodex insulation

[CC1221]

Wondering if anyone has any first hand experience with this or with insulation for less (www.insulation4less.com)? It's a foil, bubble, foil insulation that I'm considering using it to insulate the interior walls of my pole barn. A similar insulation was used for the roof of the building when it was constructed and seems to work quite well. Though I'm skeptical about the R value claims (R16 for a single layer and R21 for two), the effectiveness of the installed roof insulation almost has me sold!! I know that spray foam would be the best way to go, but I can't afford that at this point. If my math is correct, I should be able to accomplish all walls and slider door for around $800 --- which I CAN afford!!

 

[Ohmthis]

I looked into this as well, If you read the fine print to get that R value you have to do some pretty extraneous things. I think it is probably at least as good as what you have on the roof. It is considered foil-foam-foil though. Good luck with your search!

 

[rsa]

Prodex has been discussed here before. Easy to find with a search.

You can't get any more plain spoken than this quote from greenbuildingadvisor.com,

Prodex is a scam, and Insulation4Less is in violation of the federal R-value Rule.

They advertise that Prodex, a product that is 5 mm thick (a little more than 3/16 inch), has an R-value of R-15.67. This is a lie. It violates the laws of physics.

Don't send them your money.

Answered by Martin Holladay, GBA Advisor
Posted Tue, 12/27/2011 - 06:19

Radiant barriers aren't all snake oil. From GBA's Radiant Barriers: A Solution in Search of a Problem,

Radiant barriers make sense for uninsulated barns

The effect of a radiant barrier on a building assembly's R-value may be significant or insignificant, depending on whether the assembly is well insulated or poorly insulated. Radiant barriers do not significantly benefit well-insulated assemblies.

For example, consider drywall installed on a SIP wall. If the SIP has an R-value of R-30, the emissivity of the drywall hardly matters. Since the drywall is at room temperature, it's at thermal equilibrium with the other objects in the room, so radiant heat transfer isn’t a significant heat-transfer mechanism for people or objects in the room. (Radiant heat transfer only becomes significant when a radiating surface is at a significantly higher temperature than surfaces in the room or air space which it faces.)

A poorly insulated assembly, however, will benefit from a radiant barrier. For example, consider an uninsulated barn with galvanized steel panels for roofing and siding. On a hot sunny day, the steel panels are warmer than the interior of the barn, so they radiate a lot of heat. If a radiant barrier is installed on the interior of the wall, it cuts down on the transfer of radiant heat from the steel panels to the interior surfaces.

So if all you're not going to insulate any further, a radiant barrier is a good choice. If you fully insulate later, installing a radiant barrier is an interim solution, not something to build upon later. Why not just install a radiant-barrier-only product at 13¢ a square foot (plus shipping) from a place like atticfoil.com? Sure, you lose the R0.6 foam insulation value of the Prodex, but it's also 2.5 times cheaper. Note: I don't have any personal experience with atticfoil.com, but they're members of the BBB and explain nicely the unrealistic R-Value claims for bubble wrap.

Robert Riversong, a creditable source, recommends,

...plain old builder's foil, which is a kraft paper backed aluminum foil and is very inexpensive. The shiny side has to be facing down.
Answered by Riversong
Posted Fri, 11/12/2010 - 21:28

I couldn't find a price for it, but one source is Superior Radiant Insulation.

 

[CC1221]

Ohmthis/Rsa - thanks for the input. I don't know why I didn't think about searching before I asked (lesson learned!)..

I'm still undecided about how I'm going to go about this, but I may have to forgo wall insulation completely right now since the new slab is going to eat away almost all the cash I have saved up !.

I plan to install PEX and under slab insulation prior to the pour of the slab for radiant heat in the future. Looks like I'll have to keep my cold weather gear in good working order (for now!). Thanks again.

 

[Highbeam]

Save your money and do it right when you can afford to. No, this doesn't mean spray foam necessarily but it does mean to use an actual non-snake oil product.

My shop is unheated this year. I'm taking my time to do it right.