EcoFoil Floor Joist Insulation is constructed of a double layer of polyethylene bubble insulation bonded to two radiant barrier metalized sheets. This (1/4" to 5/16") thick insulation provides superior protection against radiant heat transfer and also provides an effective vapor barrier, preventing condensation which can cause mold. Bubble insulation is rated by its high reflectivity of 96%, and low emissivity of 4%. This means only 4% of radiant heat passes through the insulation. Simply put the insulation is not trying to slow the way heat passes through it, the insulation is trying to eliminate heat from passing through it.

This insulation is designed to fit in between either a studded wall or floor joists that are 24" on center. The 24" wide insulation is lightweight and includes a 3/4" flat staple tab on each side for easy installation.

R-Value Of Radiant Barriers

Rather than rating by R-value, all radiant barrier products are measured by their reflective and emissive properties. EcoFoil double bubble insulation is 96% reflective and 4% emissive, meaning the product only allows 4% of radiant heat to pass through. 

There are some companies out there posting big R-Value numbers for their radiant barriers, but those numbers are rating the entirety of the system—including the product, air gap, and other building materials. In reality, most radiant barriers by themselves have little to no R-Value. If you need to satisfy a building code of a specified R-Value, we recommend the use of a traditional insulation in conjunction with our radiant barrier in order to meet code. For more information on R-values, see our  page or contact a member of our friendly service team via chat, by calling (888) 349-3645, or using the form .