Overview
A radiant barrier is a reflective foil (usually aluminum) stapled to the underside of roof rafters in an attic. It blocks radiant heat — the invisible infrared energy that transfers from a hot roof deck to your insulation — before it ever reaches the insulation.
In DFW, where attics regularly hit 130°F+ in summer, radiant barriers reduce attic temperatures by 20–30°F and can cut cooling costs 5–15% on top of existing insulation. It's a complement to, not a replacement for, insulation.
