Radiant Barrier Attic Rafters

Attics heat up when the sun s radiant energy heats the shingles and the heat is transferred to the interior attic space through the roofing materials via conduction.

Radiant barrier attic rafters.

A radiant barrier under the rafters will keep more heat in the roofing and hence somewhat reduce the lifespan of the shingles and it will limit drying to the interior should there be a roof leak that saturates the sheathing unless the rafters are vented from bottom to top. This combines both of the standard installation methods and the benefits that each of those methods offer. The results were very telling. When a good radiant barrier is employed under the attic rafters directly before the sheathing decking new construction or along the bottom of the rafters preexisting construction a majority of the heat is reflected back through the roof and never enters the attic at all.

A radiant barrier works best when it is perpendicular to the radiant energy striking it. The heat escaping in the winter will be blocked at the insulation level while heat radiating down in the summer will still be blocked from reaching the living space. So you would order 2 500 sq ft of atticfoil to cover an area this size. The hot roof material then radiates its gained heat energy onto the cooler attic surfaces including the air ducts and the attic floor.

Radiant barriers are utilized to reduce summer heat gain in attics. A radiant barrier combo installs radiant barrier on the attic rafters attic floor over your existing insulation and or attic floor plywood decking exterior facing vertical walls and interior facing vertical walls. A control study was published in 2013 showing the radiant barrier effectiveness of paint foil backed sheathing and foil that was stapled onto the rafters. Radiant barrier applied either under the roof rafters or under the roof sheathing is probably the most common application of a radiant barrier but many homeowners shy away from it because they don t fully understand what radiant barrier is or how it works.

For really high roofs you should consider doing a flat top installation for radiant barrier for tall attics. A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic. Radiantguard radiant barrier foil insulation installed in an attics can reduce attic temperatures by up to 30 degrees when stapled with a staple gun to the underside of roof rafters by reflecting up to 97 of the radiant heat that strikes its surface thereby reducing heat. Radiant barrier installation attic radiant barrier installation most of the heat entering a home comes through the roof.