Attic Mold Soffit Vents

The photograph at left shows severe mold on the underside of roof sheathing in a 1920 s cape cod attic where there was no under roof ventilation.

Attic mold soffit vents.

Blocked soffit vents invites attic or roof cavity moisture condensation mold the photograph at page top shows an attic whose intake venting is blocked by fiberglass insulation. Vents come in various styles. Almost all homes are fitted with some kind of roof vents at the peak of the roofline be it individual roof vents hip roof ventilation and many homes have gable vents as well. Nope venting an attic is actually pretty hard here s how ventilation is supposed to work.

Few areas of mold growth are more mysterious and confusing than soffit mold growth. Plus roofing and attic ventilation systems can protect homes from the expensive roof and structural damage caused by trapped heat ice dams moisture and mold. If you see dampness or frost you need better roof ventilation and some attic vents. Moreover if you have asphalt shingles on the roof attic.

Attics usually have a passive ventilation system in which outside air comes in through the soffit eave vents at the bottom warms up in the attic and escapes through the can or ridge vents at the top because hot air rises. Attic ventilation is a two part process. First air enters through the soffit vents. For the best results place roof ventilation near the roof s peak and soffit vents in the eaves.

Yet many attics with ventilation far superior to the code requirements suffer from mold issues. A soffit vent is simply a vent installed into the underside of your home s eaves called the soffit that permits fresh outside air to be drawn up into the attic. One house can suffer from major mold growth while the neighbor s home is spotless. The most common cause of attic mold by far is blocked or insufficient ventilation of the attic space.

How to check attic ventilation. And many homes with terrible attic ventilation are completely mold free. Unlike growth in other areas of a home soffit growth does not appear to follow any reliable pattern. A home s ventilation system consists of everything from roof vents to the best attic fans without the right roofing and attic ventilation system your home can become uncomfortable and cost more to cool or heat.

To avoid rotting wood clumping insulation and mold your attic needs to be properly ventilated. As a certified licensed home inspector it is not correct to say too much ventilation is bad for an attic unless rain moisture is getting in. Grab a flashlight and inspect your attic during the winter. Air flows in through the soffit vents and out through the roof vents.