Eaves and Soffits

What it is.

The eave is the part of your roof that overhangs the wall. Look up underneath it from outside. If you can see the angled rafter tails and open framing, your eaves are open. If you see a flat finished surface running from the wall out to the roof edge, they are enclosed. That flat surface is the soffit.

Why it matters.

Fire and hot gas move upward. When a fire burns near the wall, heat and embers rise and get caught in the pocket an open eave creates, held against bare structural wood with nothing between them and the attic. An enclosed soffit removes the pocket and gives the embers no place to rest.

What good looks like.

Eaves fully enclosed with a noncombustible or ignition-resistant soffit, with no gaps at the wall junction or at the roof edge.

How it is judged.

California requires eave and soffit assemblies to resist flame penetration under direct exposure. The two accepted test methods are SFM 12-7A-3, which applies a 300 kilowatt flame for ten minutes, and ASTM E2957, which runs for forty minutes. The 300 kilowatt exposure is the most severe in the SFM series, because the underside of a roof overhang is the worst place on a house for trapping heat.

What we will ask you.

"Stand outside and look up under your roof overhang. Do you see exposed rafters and open framing, or a flat finished surface?"

Back to what we look at