Vent your bath and kitchen exhaust fans through the roof through a special roof hood. Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.
By the DIY experts of The Family Handyman Magazine:March 2002
The best exhaust fan venting is through smooth, rigid ducts with taped joints and screwed to a special vent hood. Insulate the duct to prevent condensation.
If you’re tempted to vent your exhaust fan through an existing roof vent, or even vent it into the attic, don’t do it. First, you’ll partially block your roof vent with the piping, reducing the flow of cooling air through your attic. Second, during cold winters, you’ll be blowing warm, moist air onto a cold surface (the roof vent and roof plywood). The water will condense and drip into the insulation below and perhaps into the house. Special bathroom fan roof vents, available at home centers, don’t take long to install and send moist air outdoors.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.
