In all cases the ducting needs to conduct the exhaust to the building exterior and needs to terminate in an animal proof vent cover.
Bathroom ventilation through attic vent.
Climb into the attic and clear away any insulation from around the hole.
Draw a mark on the bathroom ceiling where you d like to install the vent fan.
Try to keep it close to the fan location.
An enclosed toilet would require its own exhaust fan exhaust fans approved for installation in wet areas would need to be located over or near the shower or tub bathroom doors should have at clearance to the floor.
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.
Get an instant vendor neutral estimate of bathroom ventilation options and costs in your zip code our cost guide has been updated for 2020 to reflect current fair wages and material option costs for bathroom vent.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
Start in the attic and drill a hole through the roof in the desired vent location.
It cannot move air to a crawlspace or attic.
Options for venting a bathroom exhaust fan include best to worst.
There are several other factors to consider for proper ventilation such as.
This section notes that air exhausted from the bathroom must be sent outdoors not indoors to the same residence or indoors to any other dwelling unit.
Up through roof down through floor or crawl area.
Bath vent fan duct routing.
Leave the drill bit sticking through the roof so you can find the hole.
Both bathrooms are vented by a single in line fan that has one exhaust vent running through the roof.
Through the roof or an exterior gable wall.
Each fan vents separately out the roof.
From up on the roof use a jigsaw or reciprocating saw to cut a 4 in.
At bathroom ventilation codes specs home.
One in line centrifugal fan can be mounted in the attic to exhaust the moisture from two bathrooms.
Use an extra long 3 8 inch diameter spade bit to bore a reference hole through the ceiling and into the attic.
The model ventilation codes building codes mechanical codes plumbing codes do not generally discuss exhaust vent duct direction and routing such as up or down through attics or crawl areas but all of the model codes require that the vent fan must exhaust to the building exterior.
While this may seem obvious homeowners may out of convenience direct the vent into either of these locations.