My bathroom exhaust fan is vented into the attic above. During the winter, the fan collects condensation that leaks onto the floor below. How can I stop this?
Tim Stockton, Via Email, None
Contributing editor Martin Holladay replies: You have one clear problem, and perhaps a second. First, your bath fan should not be ducted to the attic but to the exterior. Second, your fan and its ductwork may be poorly insulated.
All bath exhaust fans should be ducted with rigid galvanized ductwork to the exterior, ideally to the nearest gable wall. The duct first should rise vertically to an elbow; from the elbow, the duct should slope downward to the gable termination. (Sloping the duct toward the exterior allows condensation to drain away.) Support the duct with duct hangers or stiff wire to prevent sagging.
All duct joints should be secured with sheet-metal screws. It’s not necessary to seal…