What Is Air Sealing — and Why It Matters More Than You Think

Insulation and air sealing solve two different problems. Insulation slows heat from conducting through your ceiling. Air sealing stops conditioned air from physically leaking out of your house through gaps and cracks. You need both — and the order matters.

Think of insulation like a sweater and air sealing like a windbreaker. A thick sweater does little in the wind. In a Central Valley summer, hot attic air pushes through every unsealed top plate, wire penetration, recessed light, and plumbing chase — and your cooled air escapes the same way.

That's why we air seal before we insulate. We seal top plates, penetrations, and gaps with fire-rated foam and caulk, then blow insulation over a tight envelope. Insulating over unsealed leaks buries the problem and wastes a chunk of what you paid for.

Air sealing is also the cheapest part of the job relative to its impact. Dollar for dollar, it's the highest-return step in most insulation projects — and it's the step budget contractors skip.

If a quote doesn't mention air sealing, ask why. Ours always does.