A few years ago, radiant barriers were the new hot thing. Now in most parts of California, they are the new required thing.
As of June 2001, homes in most of California’s populated areas are required to have radiant-barrier roof sheathing to meet the state’s Title 24 energy code as modified under Assembly Bill 970. And in many building practices and regulations, where California goes, there goes the nation.
Radiant barriers are thin sheets of tin foil-type material laminated to sheets of oriented strand board. The sheets are laid metal side down and are designed to reflect the hot rays of the sun back into the sky instead of letting them penetrate into and heat the attic. Hotter attics create hotter homes, which create a need for larger cooling systems.
TechShield is one such radiant barrier, made by Louisiana-Pacific. The California Energy Commission cites an LP comparative study of two modular homes, one with TechShield and one with standard roof sheathing. During a month when the average daytime temperature was 87 degrees, the air conditioner in the home with TechShield used 16% less energy to keep the house cool than the home without the radiant barrier.
According to the CEC, radiant barriers are popular with building and remodeling clients because while utility bills can be cut from 10% to 30%, there is virtually no maintenance or even awareness the barrier is there. Moisture buildup is avoided by perforations over the surface of the mate-rial, and little tears and holes in that surface will not significantly diminish the sun-reflecting benefits.