Is there a strong argument for using a bubble insulation or foil product on trusses instead of just a radiant barrier to reduce attic temps?

Asked by Justin Brooks
Kernersville, NC

The house is average construction, built in 2008, with a very inefficient and arguably undersized HVAC system. I am trying to limit attic losses as much as practicable. I have a vaulted ceiling and am wrapping the existing framing/batt insulation with a double bubble-foil insulation. My current plan is to use the simple radiant barrier to cover the trusses and additional framing elsewhere in the attic. I have 12 inches (R-30) of CertainTeed blown-in insulation everywhere except for the cathedral ceiling framing. I am trying to conserve costs, but if I can expect noticeable results with the more expensive bubble barrier throughout I will do so.


Danny Kelly

Answered by Danny Kelly

Charlotte, NC

Kelly McArdle Construction

August 24, 2010

A standard radiant barrier will perform just as well as the bubble-wrap radiant barrier. I would install this on the bottom of the rafter in a stick-framed roof or on the bottom of the top chord of the truss if you have a truss roof.

Prior to installing a radiant barrier, you should do the following:

  1. Air seal the ceiling
  2. Duct seal the HVAC ducts
  3. Bring insulation up to R-38.

These are cheaper and will give you a better payback than a radiant barrier.

For more information:

Check our best attic insulation Q&A to see what other homeowners and contractors are saying about foam insulation, duct sealing, radiant barriers, etc.

Tagged In: attic insulation, radiant barrier

Do you have a question about greening your home? GreenHomeGuide invites you to Ask A Pro. Let our network of experienced green building professionals – architects, designers, contractors, electricians, energy experts, landscapers, tile & stone specialists, and more – help you find the right solution.