The next best location for a bath fan cap is a wall that s at least three to five feet from a roof overhang.
Install bathroom exhaust fan roof.
A single exhaust exits through the roof figure a.
This system is quiet too.
Start in the attic and drill a hole through the roof in the desired vent location.
You can use the existing switch wires and ductwork.
Attach the bathroom fan to the joist.
Use an extra long 3 8 inch diameter spade bit to bore a reference hole through the ceiling and into the attic.
Use the information below to select a fan.
You mount a switch in each bathroom.
The installation is easiest if you re replacing an existing fan.
Access the attic and bring your light cordless drill screws and bathroom fan housing.
Leave the drill bit sticking through the roof so you can find the hole.
Try to keep it close to the fan location.
You will need a partner for this step as you cannot see the ceiling from this position.
Draw a mark on the bathroom ceiling where you d like to install the vent fan.
Climb into the attic and clear away any insulation from around the hole.
Secure the vent flanges with roofing nails before installing the shingles.
Most roof overhangs today have continuous soffit ventilation strips.
Make sure to check my other vide.
A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan.
Place the fan in the cut out hole so that the bottom edge of the fan is flush with the bottom of the ceiling drywall.
From up on the roof use a jigsaw or reciprocating saw to cut a 4 in.
Also it helps to get a fan that s the same size as your existing fan so you won t have to adjust the size of the ceiling hole.
Apply roofing adhesive on the underside of the flanges to seal.
This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.