step by step how to install a bigger bath fan
Steps // How to Upgrade to a Bigger Bath Fan
1 ×

Remove The Old Fan

 
Step One // How to Upgrade to a Bigger Bath Fan

Remove The Old Fan

step by step how to install a bigger bathroom fan remove old fan
Photo by Wendell T. Webber

Turn off power to the fan at the circuit breaker, and lay down a drop cloth to collect debris. Pop off the fan's cover and remove the screws holding the fan's housing to the ceiling. (With a fan that's screwed directly to a joist, you may need to trim back the drywall to access the screws.) Pull down the motor housing and disconnect the wires.

 
2 ×

Prep The Opening

 
Step Two // How to Upgrade to a Bigger Bath Fan

Prep The Opening

step by step how to install a bigger bathroom prep opening for bigger fan
Photo by Wendell T. Webber

Compare the size of the existing opening to the size of the new fan's housing by placing the housing against the ceiling. If the opening is smaller or has a different shape than the new housing, as was the case here, trace the outline of the housing on the ceiling, then cut along the line with a jab saw. If the hole is bigger than the new housing, you'll need to fill in around it.

 
3 ×

Insert The Fan

 
Step Three // How to Upgrade to a Bigger Bath Fan

Insert The Fan

step by step how to install a bigger bathroom fan insert fan into opening
Photo by Wendell T. Webber

Tilt the fan into the opening, and screw one lip of the housing to the bottom edge of a joist. If there isn't a joist in the right spot, get a helper to hold the fan from below while you attach brackets to the faces of two joists from above (see Step 4). If you can't access the fan from above, enlarge the ceiling hole enough for you to reach in and attach the brackets from below.

 
4 ×

Fasten The Brackets

 
Step Four // How to Upgrade to a Bigger Bath Fan

Fasten The Brackets

step by step how to install a bigger bathroom fan fasten brackets for fan in attic
Photo by Wendell T. Webber

Up in the attic, extend the two support brackets to the facing joist, and screw each one in place, as shown.

 
5 ×

Connect The Wires

 
Step Five // How to Upgrade to a Bigger Bath Fan

Connect The Wires

step by step how to install a bigger bathroom fan connect wires in attic
Photo by Wendell T. Webber

Thread the electric cable from the bathroom through a cable connector and into the junction box. Remove the box cover. Using wire nuts and electrical tape, connect the fan's wires to the cable's—black to black, white to white, green to bare copper—as illustrated in the fan's instructions. Replace the cover.

 
6 ×

Attach The Duct

 
Step Six // How to Upgrade to a Bigger Bath Fan

Attach The Duct

step by step how to install a bigger bathroom fan attach the duct
Photo by Wendell T. Webber

By code, a bath fan must vent moisture to the outside, ideally through a duct to the roof or, as shown here, through a gable wall. In cold climates, use insulated duct (above) to guard against condensation in the duct. Zip-tie the duct to the fan's exhaust port and to the exhaust vent, then seal the connections with foil tape.

 
 

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.