The vent goes through the ceiling in the bathroom and vents out through the exterior wall . The vent should not stop in the attic, must vent outside, (moisture) cannot be vented inside the house.

Out through the soffit if not by a window.

Fred S, yes that way also.

Not sure where you are, but here venting a bathroom fan out through the soffit is not allowed (per building code) as moist air will just enter back in to the attic via soffit vents. Also need to be away from windows ... Sometimes through roof is the only option left.

It is not the most ideal way in a continuously vented soffit, but it is done quite often in areas where heavy snow would cover the roof. There is nothing prohibiting it in the International Residential Code (IRC). This is what a proper soffit vent outlet would look like.

A continuously vented soffit needs to have no venting or blocked vents three feet in both directions from the bath exhaust.


M1506.2 Exhaust openings.

Air exhaust openings shall terminate not less than 3 feet (914 mm) from property lines; 3 feet (914 mm) from operable and nonoperable openings into the building and 10 feet (3048 mm) from mechanical air intakes except where the opening is located 3 feet (914 mm) above the air intake. Openings shall comply with Sections R303.5.2 and R303.6.

Two more for you.

R303.5.2 Exhaust openings.
Exhaust air shall not be directed onto walkways.


R303.6 Outside opening protection.
Air exhaust and intake openings that terminate outdoors shall be protected with corrosion-resistant screens, louvers or grilles having a minimum opening size of 1/4 inch (6 mm) and a maximum opening size of 1/2 inch (13 mm), in any dimension. Openings shall be protected against local weather conditions. Outdoor air exhaust and intake openings shall meet the provisions for exterior wall opening protectives in accordance with this code.

I live in Tennessee. Not sure about the codes here. Nonetheless, the installer broke my carnal rule of thumb: don't direct moist air into an enclosed space. Fred S.: Thank you for your advice. I'll have to check the location of my soffit vents before proceeding. I have windows everywhere so I may have to go through the roof.

Yes, the standard code says don't vent bath fan into attic, but I didn't post that one here because you already knew that :)

Sometimes going through a gable wall is another option, less prone to roof leaks down the road. Obviously depends on roof layout, presence of windows on that gable wall etc as well.

I hadn't considered using the gable vent idea. Thanks for another option!

If you don't vent through the roof it will put moisture in the attic and could make mold. To do it right you need to vent through the roof.