Exhaust Into Attic

Small diameter ducts could trap grease creating a fire hazard.

Exhaust into attic.

When we got into the attic i quickly noticed the smell moisture and what i could see as mold on the roof rafters above each bathroom. Cover the hole that you are not using for exhaust and secure the hood to its. Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside. The reason you don t vent into the attic is because when the attic is colder than the vent air moisture will condense inside the attic space causing mold and other problems.

The duct for your exhaust fan needs to be run to the outside of the house to remove the chance of a fire hazard. Surprisingly bathroom fans are not required by some building codes. First you ll partially block your roof vent with the piping reducing the flow of cooling air through your attic. Options for venting a bathroom exhaust fan include best to worst.

The duct should be smooth and straight with as few bends as possible. Bathroom exhaust fans perform an important function by removing excess moisture from your home. Hot air exhaust vents located at the peak of the roof allow hot air to escape. 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.

This can be a serious problem in cold weather if the living space is not properly sealed off from the attic. Step 2 run the ducts. In either case do not vent into the wall or the attic. Duct already wrapped in insulation at home centers.

After further inspection it was evident the current home owners vented their bathroom exhaust fans directly into the open attic space and not to the outside. All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans. If you re tempted to vent your exhaust fan through an existing roof vent or even vent it into the attic don t do it. Your vent hood will have places available for either attic or wall exhaust.

The kitchen vent fan must exhaust directly to the outside not into an attic crawlspace or a space between floors. It may also violate a shingle warranty. The fan s installation instructions should specify the diameter of the duct.