Insulate your attic access door hatch with weatherstripping and foamboard to r10.
Bathroom fan insulation attic.
The building code requires a bathroom exhaust fan to vent outside the building so installation of a new bathroom fan necessarily involves installation of ductwork.
Caulk foam seal all penetrations into the attic space ie duct chases plumbing chases wiring electrical boxes from lights down below.
This is much easier to do if you have attic access because if you don t you usually have to remove some ceiling drywall and run the ducts along a joist.
The first step is to head to the attic.
Bathroom vent fan ductwork insulation.
Bathroom exhaust fans perform an important function by removing excess moisture from your home.
If you see that your duct isn t insulated at all pick up duct insulation at the home center.
If bath fan ducting isn t properly insulated the moist air from your house will condense inside the duct.
While insulating you can make some mistakes.
When venting a bathroom exhaust fan make sure to vent the air to the outside rather than into your attic where it can cause mold and mildew to form.
Before you rush to the attic or go the roof to check for any leaks make sure the exhaust fan duct is properly insulated and run the fan more frequently for a prolonged period.
You may find that the insulation simply needs to be refastened.
Seal off the chimney chase with sheet metal and or non combustible caulk.
To avoid mistakes not running it at all consider installing switches with built in timers.