The truth about attic bathroom venting.
Bathroom fan vent exhausts into attic.
Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof.
This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.
Surprisingly bathroom fans are not required by some building codes.
In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover.
Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.
We explain how to install bathroom exhaust fans or vents the vent ducting.
Bath vent fan installation building codes bath vent fan troubleshooting bath vent fan repair.
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.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.
Options for venting a bathroom exhaust fan include best to worst.
But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms.
How to install a bathroom vent fan.
You should never exhaust the bathroom fan directly into the attic.
It eliminates the need for routing ductwork through the house and these fans usually dry the bathroom more quickly.
All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans.
Bathroom code does address the issue of moving odor and moisture laden air from the bathroom to the outside.
You d often blow air from one bathroom into the other and local building inspectors wouldn t approve it.
I would by lying if i told you that it will cause problems it may be totally fine.
The lowdown on venting your bath fan into an attic is that it can be done but it should terminate on the outside.
This article series explains why bathroom vent fans are needed and describes good bath vent fan choices necessary fan capacity and good bath vent fan and vent duct installation details.
In fact i have seen numerous houses that haven t yet had signs of mold with the bath fan venting incorrectly.
Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside.
No you cannot vent your bathroom exhaust fan 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.
