Assuming that your fan is already installed the first thing you need to do is access the fan from above in your attic.
Once you locate the fan you want to look at any obstacles around the fan that may impede venting. If you are close to an exterior wall you can actually vent out this wall. However if your bath fan is in the middle of the house away from exterior walls you’ll have to vent through your roof.
If you’re going to vent through your roof you need to purchase the bath roof venting kit.If you’re going to vent through the wall then the wall venting kit will be required.These kits are readily available at your local DIY store like Lowes or Home Depot. If one of these handy stores is not in your area you can always turn to the internet and have one shipped to you. These kits aren’t very heavy so the shipping charges should be very nominal.If venting through the wall you’ll need to find a good location to cut a hole in the wall. The size of the hole will be the size of the small inlet the cover vent has protruding about two inches or so. If you mark a hole this size and drill a starter hole and then use your reciprocating saw, you should easily be able to cut through wood walls. If you have vinyl siding you’ll need to cut the circle of siding away first, this is easily done with a utility knife.If venting through the roof the procedure is the same only you’ll be cutting through your shingles first.The kit pictured is the wall venting kit.
Okay now you have a hole. You should attach the exterior vent cover around the whole. The wall cover has four screws and resembles a dryer vent cover. The roof vent looks very different and a has a protruding straight edge that you need to slide carefully under the shingles that are uphill from your hole. By uphill I mean if you’re looking up towards the peak of the roof.
Once you get the vent covers installed you need to locate the protruding pipe section on the fan itself. This is a metal section resembling pipe that protrudes about 3 inches from the fan. You need to take your vent which is similar to your dryer vent and slide it over the pipe end on the fan. Take one of the included zip ties and secure the vent to the fan pipe. Repeat this step at the exterior vent cover. Then you should test to see if the fan is venting properly. If you discover any air leaks you can use metal conduit tape to seal them.