How To Install Radiant Barrier In A Cathedral Ceiling

[CrazyTexan]

Nice method if you want to compress the batt insulation reducing its r-value and in addition sandwich the radiant barrier making it completely ineffective. Radiant barrier in a cathedral ceiling is not a good idea. Properly insulating is all you need.

[AtticFoil]

@CrazyTexan I mention in the video, by using 3/4" foam strips you are only compressing the insulation 3/4 of an inch. In a typical 2x6 or 2x8 rafter, this is not a huge deal. However, getting a radiant barrier as the first line of defense (even with compressing the insulation slightly) will cause LESS heat to get through the cathedral than with insulation alone. The best description is that you want to make a refrigerator and wrap it with foil. This will slow both radiant & conductive heat.