Venting two bathroom exhaust fans through one roof duct won t work sorry to say.
Install bathroom exhaust fan duct through roof.
The bathroom exhaust ventilation fan disperses air through an opening in the fan housing which is usually 3 inches in diameter and ideally faces in the direction of the ventilation system outlet.
The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood.
A 3 or 4 inch duct connects to the outlet on the fan housing and runs to a side wall or to the roof and connects to a vent cap that allows the.
To vent a bath fan through the roof you must first prepare a ductwork connecting the roof top to the bathroom.
Vent your bath and kitchen exhaust fans through the roof through a special roof hood.
Pass the opposite end of the duct through the hole in roof.
Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.
In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover.
Secure the fitting with foil duct tape.
If it is actually rain water coming in through the duct from the roof confirm that is there a cap on the duct if not install one.
By the diy experts of the family handyman magazine.
Use a nylon zip tie to securely hold the insulation to each end of the duct.
But you can install one fan in your attic for both bathrooms and make your bathroom quieter too.
Typically an exhaust fan that is vented through the roof has a roof hood or roof cap which allows air to exhaust but provides protection from wind blown rain.
How to properly duct an exhaust fan through a roof.
The master bathroom and the 2nd bathroom vent through the roof and through the same opening.
I prefer to run my exhaust vents downward and out through the basement because there is no condensation inside the ducting but if you must go up.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
Then drill a hole on the roof top.
Over there mount the vent hood using tri polymeric locking seal paste and put the nails to strengthen it.
Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.
Next use aviation snips to cut slits into the sheet metal sleeve.
The 2nd bathroom vent drips on the floor and is ruining the ceiling.
The 2 pipes one a 4 master and the other a 3 2nd do not go through the ceiling but into a common box that goes through the roof.