Bathroom Exhaust Fans Into Attic

Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.

Bathroom exhaust fans into attic.

In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover. This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space. Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems. For optimum performance locate it between the shower and the toilet.

Vent your bath and kitchen exhaust fans through the roof through a special roof hood. Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out. The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. Each bathroom has its own exhaust fan.

Climb into the attic and clear away any insulation from around the hole. The model building codes adopted by most jurisdictions typically require bathroom ventilation to be provided either by an operable window 3 sq. Each fan vents separately out the roof. Surprisingly bathroom fans are not required by some building codes.

Bathroom ventilation requirements summary. 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. Use an extra long 3 8 inch diameter spade bit to bore a reference hole through the ceiling and into the attic. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons.

When venting a bathroom exhaust fan make sure to vent the air to the outside rather than into your attic where it can cause mold and mildew to form. 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. Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside. One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms.

Or greater or by mechanical means a bathroom vent fan 20 continuous or 50 cfm intermittent vented to the building exterior. Bathroom exhaust fans perform an important function by removing excess moisture from your home. The problem with this approach is that all of the moisture in the air goes onto the wood sheathing insulation wood rafters and wood ceiling joists which can lead to mold growth and rot. Draw a mark on the bathroom ceiling where you d like to install the vent fan.