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· Registered
1 Posts
Discussion Starter · #1 ·
Hi everyone,

I live in a modern stucco sided two story house with an attic. Both of the bathrooms upstairs have windows with no exhaust fans. I'm starting to notice small mold spots in the master bathroom so its time to install exhaust fans in both bathrooms.

I'm ok with the fan installation, electrical and switches but Im fuzzy on the fan exhaust strategy.

One fan with be 6 inch duct and the other 4, Im assuming insulated flex is the way to go. Each bath room is close to a gable vent at each end of the attic, with one of the gables holding a gable fan.

Im assuming the best route here is to cut a hole in the wall of the house near the gable vent and through the stucco and install a wall cap to the outside. Whats the right way to connect the cap to the ducting? Im visualizing the duct work coming to the inside of the wall, the cap on the outside, and with the wall being a couple inches thick of stucco and wood Im not sure how to connect everything up the right way to keep mouisture out of the walls.

Whats the right way to route the ducting from these exhaust fans?

Thanks for all the comments.


· GC/Master Plumber/Mech
1,517 Posts
It's as easy as using dryer vent flex duct and installing a dryer vent for each fan.

You don't need insulated flex duct. Really simple

· 30 year tech
427 Posts
If you don't use insulated flex you will get condensation dripping. Also the moisture your trying to exaust could build up in the pipe.

The cap should come with a peice of round pipe to hood to it. Hook the flex duct to that and make sure to pull the insulation all the way over the pipe. Caulk the cap and skrew or tap con into the stucko.

Good venting.:thumbsup:
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