Attic fans are usually installed under the gable roof. Basically, it should be away from anything that is protruding in the airspace or your crawlspace.
For example, if the studs are 2 feet (0. 61 m) apart, you’d need a piece of plywood that’s at least 2 feet (0. 61 m) wide.
Check the box your attic fan came in to see if the manufacturer included a pre-cut circle that’s the same size as the fan’s body. If they did, you can trace that instead.
Install the fan in the specific direction indicated on the box.
It might be helpful to have someone holding the fan while you hammer in the plywood.
Wear a hard hat and boots with good traction when you’re up on the roof. Ask someone to be there with you when you get on the roof in case you need help for any reason. Don’t get on your roof if it’s wet or you could slip.
Just loosen the 2 corners closest to the hole on each shingle. Don’t take the shingles all the way off.
The open vent on the fan should be facing down into your attic, and the closed off top of the fan should be facing up.
You can also apply a dab of roofing adhesive over the screws on the flange to protect them from water damage. You can find a roofing adhesive online or at your local home improvement center.
