STEP 5: PREPARE EXTERIOR VENT HOLE
Homes with smooth siding create an ideal work surface for attaching a vent cap. Make sure your vent cap is long enough to connect to the range hood, then apply caulk to the inner lip of the vent cap and position it inside the hole. Screw the vent cap securely in place and caulk again around the exterior to create a tighter seal.
If your home has lap siding or an uneven exterior, cut out a square of the siding around the vent hole and place a square piece of PVC trim—with an appropriately sized vent hole—in its spot. Attach the vent cap to the hole in the trim, then caulk and screw the vent cap securely to the trim.