Options for venting a bathroom exhaust fan include best to worst.
How to vent bathroom exhaust fan in attic.
The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood.
Drill a reference hole draw a mark on the bathroom ceiling where you d like to install the vent fan.
Through the roof or an exterior gable wall.
You should never exhaust the bathroom fan directly into the attic.
No you cannot vent your bathroom exhaust fan into the attic.
Take a look at the installation manual for your fan brand and model.
The correct way to vent a bathroom fan through an attic is to terminate the vent either to the roof or to the gable wall.
The manufacturer will give guidance on the total duct length permitted.
In general you can try venting a bath vent fan down but the combination of down direction elbows and total run length may mean that it s ineffective.
Measure the vent fan.
Either way the vent will have to go directly to the outside and installed with a vent hood cover.
Use an extra long 3 8 inch diameter spade bit to bore a reference hole through the ceiling and into the attic.
For optimum performance locate it between.
Duct already wrapped in insulation at home centers.
You can find 4 in.