Installing A Bathroom Exhaust Fan

Whenever I'm renovating a bath, I recommend installing a bathroom exhaust fan if there isn't one already. It's a fairly simple installation, depending on where you can vent the fan to.

The fan itself will range from $12, for the most basic unit, up to $160 or so for one that's quiet with a light. In addition to the fan, you'll need a venting kit to actually get the humid air outside. The roof venting kit is around $20 and the wall venting kit is closer to $15.

For the Inglewood bathroom I've been working on, the roof above was a very flat rubber roof. It was in great condition and I wanted to avoid punching any holes in it that might develop into a leak later. For this reason, we decided to mount the fan on the outside wall. This proved to be much easier. Here's the process:

1. Decide where you want the vent (roof or wall), and cut the hole. (Always think this through first!) Usually a jig saw or reciprocal saw will do the trick, depending how much access you have to the space. The fan kit includes a template so you can make sure the hole is the right size.

2. Next, trim the sheet metal that will be the tube that will attach to the flexible duct and the outside vent. For my installation, I only needed a few inches. This is similar to a dryer vent installation.

3. The sheet metal tube will 'snap' onto the exterior vent. With this in place you can slide it through the hole from the outside and the screw the vent to the exterior wall. It's a good idea to caulk around this with some silicone caulk to avoid any water entry at this point.

4. Attach the flexible duct to the vent with the plastic cinch clamps that are included in the kit. These will make sure the flexible duct is tight.

5. Depending on how accessible it is, you can hang the fan first, but I did it after the vent was installed so I could get to everything. Make sure to hang the box so that it will end up flush with the drywall. They usually have fold over tabs that are the right depth for 1/2" drywall. The fan itself will come out of the box, giving you access to the wiring panel. After making the electrical connections you can put the fan back in place.

6. That's it! After drywalling and paint you can put the fan cover in place and try it out!

-Peter

www.CarpentryGuy.com