Exhaust Into Attic

Venting into the attic sends excess moisture to that space which can cause mold and other problems.

Exhaust into attic.

Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside. You can find 4 in. Intake vents located at the lowest part of the roof under the eaves allow cool. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood.

It may also violate a shingle warranty. Because what happens is when the insulation gets moist from all that moisture that s being dumped into the attic it completely cuts down on the r value of the insulation. We ve also seen homeowners have to replace all their roof decking because it became rotted from the excess moisture. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Dumping bathroom exhaust into an attic or under roof space invites costly mold contamination frost under the roof in freezing climates moisture damage to roof sheathing possibly even plywood delamination or rot roof failures and shorter roof shingle life. Duct already wrapped in insulation at home centers. No you cannot vent your bathroom exhaust fan into the attic. And many building codes require discharging exhaust to the building s exterior so it s just a good rule of thumb.