# Bathroom Exhaust (PVC ???)



## mc handyman

Had a new client give me a call today. They recently (2years ago) had their basement finished and a addition put on. The issue is in regards to the newly finished basement bathroom. 

It seems that the bathrom exhaust line runs though all the trusses through a 3 cut circular hole. The thing I dont get is that the contractor ran the line from an exterior wall bathroom all the way to the other side of the home and then up through the exterior wall and into the addic that has no access.

To the point, one of the couplings where the 2" schd 40 PVC is spliced is leaking and for some reason, there is moisture in the line and it has now dripped and stained the sheet rock in the basement bedroom that it passes through.

Here are my questions:

1) I have never seen schedule 40 PVC or PVC of any kind used for an ehaust line. Is that standard? Code?

2) Why is there moisture? From the shower steam? Condensation when the warm air meet the cold attic enviroment? I doubt is is insulated around the line.

3) Are you about to teach me a valuable lesson?

Thanks Guys!:thumbsup:


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## JonM

You should have an insulated pipe running out...the warm air running inside the pipe and the cold air outside the pipe are causing the condensation.Either insulate the outside of the existing pipe or get some flex pipe that already has insulation around it...I would also try to shorten the distance between the fan and the exit. Seems a long way and the fan may not be large enough to push all that air. You could get water dripping back into the fan and cause a fire.


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## charlesmd

Pvc can (and should be used and sloped).They are fart fans but people use them for removing the steam. I hard pipe them whenever I can.


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## mics_54

I always use pvc...not sched 40 though. I use F810 PVC is cheaper with fewer joints to seal, water proof, easier to install, less friction. 
In your case the vent was installed poorly. Bath or any exhaust duct should be insulated and installed so as to drain to the exterior.


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## Aframe

not being a smart A**, Are you sure it is not a plumbing vent? 
Most exhaust fans have either a 3" or 4" outlet. If they did run the exhaust fan into 2" PVC, you will not get the air movement you need.

You will get condensation build up from steam/moist air when the pipe runs through a colder area. Also on a long run, especially vertical, you are bound to have problems like you have now. Leaking at a joint shows they did not do a good job on joining the pipe. 

A proper plumbing vent will also have condensation, but that will have pitch back to the drain.


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## mics_54

Oh hell I didn't even see the 2" part ...wtf


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