According to the Berkeley Fire Department checklist vent opening in houses removes excess moisture and reduce roof and attic temperatures. Many types of vents are located in soffits, which are the undersides of a part of a building such as an arch, overhang or beam. Vents are also located in roofs ("eyebrow" vents), on tops of roofs (ridge vents), on top ends of walls (gable vents) and in crawl space. Soffit vents are most vulnerable to fire.
We recommend the following for soffit vents:
Do not block these vents without adding adequate vents. Building code requires minimum venting and this is barely adequate for most houses. Reduced venting can lead to serious decay damage from accumulation of condensation in the attic.
Consider advice from a contractor about your options. If you are considering replacing your roofing material, then the roof type vents should be seriously considered. Garble vents are also a good retrofit option for some walls.
Do not have large plants at the ground line directly below soffit vents. A poorly maintained bush about 3' high can burn with flames high enough to reach your soffits and go through the vents.
To prevent sparks from entering your home through vents, cover exterior vents with wire screening no larger than an 8 mesh. Make sure under-eave and soffit vents are as close as possible to the roof line.
