Tap Next on the drawing. It stays in view while you read.
Understand your roof
Bath fans that vent outside
Ask your roofer
- Are any bathroom fans venting into my attic?
- Will you run them out through the roof, and is the vent metal or plastic?
Ask them to put the answer in writing.
Why it matters
A bath fan that dumps into the attic fills it with moisture, which rots wood and grows mold.
How it should be built
Tap Next on the drawing to see it go together, layer by layer.
- An insulated duct runs from the fan to a damper vent (bathroom vent) on the roof.
- The vent’s flange slides under the shingles above and over the ones below.
- Choose a metal vent. Plastic vents get brittle and crack in the sun.