How do you install a gable vent?   A vinyl gable vent is
designed to ventilate stale air from the attic during the summer
and prevent rain and snow from dripping through. Gable vents
reduce heating and cooling costs.  Before installing the gable
vent, remove any insulation that may be in the way with a
utility knife.  Next, install the vent frame. Use boards to
build a 2-by-4 square frame. Place the frame between the studs
and the gable ends, and secure it with screws or nails. Factor
in a 1 1/8 inch gap around the entire frame. When you are
finished constructing the frame, drill 3/8-inch holes into the
vent corners. These holes connect to the exterior of the house.
Mark the position of all of the holes with a pencil or piece of
chalk on the roof, and connect the marks. This outline
represents the vent opening. Saw along this line to cut out the
opening.  Once the vent opening has been cut, see how the vent
fits. If the vent fits straight, draw an outline for a flange.
Use a circular saw to cut through the s