Installing a Vent Hood on the Roof
Start in the attic and drill a hole through the
roof in the desired vent location. Try to keep it close to the fan location. Leave the drill bit sticking through the roof so you
can find the hole. From up on the roof, use a jigsaw or reciprocating saw to cut a 4-in. round hole. Next, measure out a square slightly larger than the protruding part of the
vent. Remove the asphalt shingles with a hook blade fitted into a utility knife. Gently pry up the shingles around the hole, making room for the vent to slide under the first course.
Apply a bead of asphalt roof cement on the bottom of the vent. Slide the vent under the shingles so they cover
the top half of the vent flange. The lower half of the flange sits on top of the shingles.
Nail the lower corners with roofing nails and tar the heads.