Vent Through Roof Or Soffit

I have gotten mixed opinions on whether to vent the new fan through the roof or through the soffit eave.

Vent through roof or soffit.

They are usually easy to remove and cut holes through. Turbine or rotary vents are often seen in industrial buildings commercial spots or restaurants. Vents through walls have to terminate at least 10 feet above the ground or adjacent surface but cannot be below a vented soffit. One of the most used or popular roof vents is a turbine vent that has spinning tops.

If an exhaust vent is too close to an intake some of that moist warm air is headed in to the attic. The roof contractor recommends the soffit to minimize protrusions through the roof. Not a good thing. A soffit vent is a type of roof vent.

Steve is on to something importent there. A vent through the roof must terminate a minimum of 6 inches above the roof surface or 6 inches above any anticipated snow accumulation. Mark holes for soffit venting. However in order to make the turns necessary to penetrate the ceiling enter the attic and then descend through the soffit ductwork must make some tortuous bends.

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. Why not run vents through the soffit. For most homes the most popular and a better looking roof vent option is a soffit vent. Butt a cardboard template against the fascia and mark your soffit hole locations to begin soffit vent installation.

I am getting a new roof installed and tear off and likely a lot of plywood and am simultaneously getting a new bath vent fan. When a vent terminates directly below a window door or air intake it must be. This reduces the efficiency of the vent and may trap heat or moisture in the elbows. Make the vent hole 1 2 in.

Add soffit venting first.