Vent Bathroom Fan Through Soffit Or Roof

There is no definitive answer in the codes that pertain to where the air must vent out of the house.

Vent bathroom fan through soffit or roof. Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot. So then the argument is that your humid bathroom exhaust comes out and is sucked back into the attic by the soffit vents built into most roof attic systems. If you are also amongst the people who are interested in avoiding making a hole in the roof and get the deed done using a soffit you have come to the right place. However natural air flow from the outside will bring the moist air back into the attic through the soffit vents kind of like a vacuum.

To vent a bath fan through the roof you must first prepare a ductwork connecting the roof top to the bathroom. When a bathroom exhaust duct terminates in a soffit it drips. Vent your bath and kitchen exhaust fans through the roof through a special roof hood. If there are bends or dips then that means the moisture in the air can accumulate in those low parts from condensation.

But if you have a vent several feet away 10 feet is required for noxious exhaust but bathroom exhaust is not considered dangerous and not subject to this you do not have a problem code wise or not. As the warm moist air leaves the bathroom through a soffit it leaves in a downward motion. Then drill a hole on the roof top. And the closer the termination is to the soffit vents that supply ventilation air to the attic the more likely that moisture from the bathroom will be drawn into the attic.

Airflow is best conducted when it has fewer bends all across the hose. A down through soffit exhaust vent design by leaving warm air in the exhaust duct when the fan is off creates a heat trap that reduces heat loss out of the bathroom through the exhaust fan duct when the fan is off in comparison with up routed vents or even horizontal vents through a gable end wall. In cold weather it forms icicles. I have gotten mixed opinions on whether to vent the new fan through the roof or through the soffit eave.

The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood. The good majority of bathroom fans are vented through the roof while some people are choosing to soffit vent them as an alternate. And while both a roof vent and an overhang vent perform this task there is one big difference. This one right here is a vent from the bathroom fan and it should never be in a vented soffit since t s causing the homeowners a lot of problems.

That s why wall terminations are preferable to soffit terminations. The roof contractor recommends the soffit to minimize protrusions through the roof.