How to Install a Bathroom Exhaust Fan
- How to
- November 17, 2019
When it comes to home ventilation, a bathroom vent is a crucial addition. Bathroom exhaust fans help remove odors, moisture-laden air and heat from the bathroom. In houses with multiple bathrooms, none of the bathrooms should share a vent no matter how close they are to each other. It’s best if each bathroom has their own exhaust fan. Mold growth, steamy mirrors, foggy windows, and other moisture-related problems can all be prevented with proper bathroom ventilation. For a bathroom with a size around 79 square feet, a small bathroom exhaust fan should provide adequate ventilation. Medium bathroom fans are adequate for bathrooms up to 100 square feet.
Here are the steps you should take when installing an exhaust fan in your bathroom.
Create the Hole
Cutting a hole based on the size of the fan you’re installing is the first step you should take when installing a bathroom exhaust fan. It is best if the bathroom exhaust fan is placed above the toilet. Avoid placing it directly above the bathtub or shower. You should start by inserting a 16-inch roofing nail into the drywall of each corner where the fan will be installed to mark the location. The length of the nails should protrude into the attic, where you will continue installation. From the attic, find the location of the nails and outline the location with a pencil. Drill a hole in the drywall large enough to accept a saw blade, then cut out the plaster or drywall with a jigsaw or reciprocating saw. If the roof is inaccessible or there is no attic, locate a joist from the bathroom by using a stud sensor and use the fan enclosure as a guide while you cut the opening from below. Remember, never vent into the attic or a subfloor because the moist air you’re exhausting can create an environment perfect for mold growth.
Attach Fan Enclosure
Now it’s time to attach the fan enclosure to the joint with screws. Start by pushing back or cutting the insulation. There should be a 6-inch gap between the unit and insulation. Block the fan off from the insulation by cutting the pieces of a 2-foot x 4-foot board to fit between the joists then attach the pieces of wood with screws.
Make a Hole in the Roof
If you’re installing a bathroom fan side vent this won’t apply, otherwise keep reading! On the underside of the roof trace a circle large enough for the tailpipe and roof vent. Drill a hole through the roof using the traced circle for reference, then cut the circle out with the reciprocating saw. Next, cut the shingles on the roof from around the hole without damaging the roof paper underneath.
Roof Vent Installation
Slide the top flange of the roof vent under the shingles above it and let the bottom flange rest on the shingles below it. Seal the roof vent by applying roofing adhesive to the underside of the flanges. Use roofing nails to secure the vent flanges and seal the sides of the roof vent by installing shingles.
Connect the Fan
Once back inside, attach the flexible duct to the duct connector and slide clamps over the roof cap and fan and also the tail of the roof vent and fan. Tighten the clamps securely and wrap the joints with HVAC tape.
Wire the Fan and Switch
First make sure you cut off power at the circuit breaker. After shutting off the power, if no wiring is present then run wire cable from the switch to the fan. Use the manufacturer’s instructions to help you connect the wiring, then plug the fan motor into the built-in receptacle. If the fan and light switch has existing wiring, splice the white “neutral” wires and connect the grounds with wire connectors. Always take safety precautions such as using tools with rubber grips and wearing shoes with rubber soles when connecting wires. Next, connect power to both of the switches via two pigtails spliced to the feed wire. Connect the red and black wire to t heir switch terminals. Refer to the manufacturer’s instructions for testing and operating your bathroom fan.