Why Adding More Fiberglass Won’t Fix a Hot Attic: The Radiant Barrier Missing Link.
If you have 15 inches of fiberglass and your house is still hot, adding 15 more inches won't fix it. Here’s why: Fiberglass is designed to stop conductive heat (heat that moves through touch), but it is almost invisible to radiant heat (heat from the sun).
The "Sponge" Effect Think of fiberglass like a big sponge. In the Texas sun, your roof shingles get up to 160°F. That heat radiates onto your fiberglass, which soaks it up until it can’t hold any more. Then, it "bleeds" that heat right through your ceiling.
The Solution: The Shield + The Blanket To truly fix a Texas attic, you need two things:
A Radiant Barrier (The Shield): To bounce the sun's rays back out the roof.
Fiberglass (The Blanket): To keep the air inside your house from escaping. By using both, you create a complete thermal break that fiberglass alone can never achieve.
