How to Install a Gable Vent Fan

Looking down the length of a long, dark attic.
  • 2 hours
  • Intermediate
  • 200-400
What You'll Need
Gable vent fan
2x4 studs

Installing a gable vent fan is a great way of keeping your attic cool during the heat of summer. You will also save on air conditioning bills. Even during the cooler months, the fan can prevent the build-up of humidity caused by heating systems. You could have an expert install your gable fan for you, but if you are willing to try it yourself, it is not too difficult.

Prepare the Attic

Decide where you want the gable vent fan to go and mark out the area using a pencil or piece of chalk. Make sure that the electricity to the attic is turned off. Take your saw and make the hole where the fan will go. Make sure it is only just large enough to fit the vent.

Prepare the Wiring

If you have electrical outlets in your attic already, you will not need to do more than connect the fan to the power supply. Otherwise, you will need to run electricity to your attic first. Using the nearest junction box, run a suitable electric wire through the walls and up to your attic, near where the vent will go. Strip back any wires that come into the attic and add a socket box. Screw all of these pieces together.

Fit the Vent

Place your 2x4 studs against the hole in a horizontal position. Screw them to the existing studs in your attic wall so that they form a brace. Put the vent outside your gable and then screw it tightly in place with a screwdriver. Make sure that it is tightly secured and then caulk around the outside using weatherproof caulk.

Fit the Fan

Take your gable vent fan and brace it against the studs you installed previously. Screw the fan into place from the inside, making sure that all of the hardware inside the fan is properly assembled. You may have to remove elastic bands from the blades of the fan before starting it up, for instance. Follow your manufacturer's guidelines. Make sure that the fan is properly wired and then plug it into your outlet.

Finishing Up

With the fan in place, apply a layer of caulk around the inside wall, making sure all the holes are completely sealed. This will prevent hot air from escaping back into the room. When you have finished, turn your circuit breaker back on and check that the fan is working properly. Allow it to run for about an hour and then check the seal around the fan and the vent. If necessary, apply more caulk to the outside edges.