Is it legal to connect a bathroom vent fan to a plumbing exhaust pipe?

This doesn't seem like a great idea but the second floor bathroom ceiling vent fan has never been vented to the outside and it would have to go through the soffit or roof at best, not near gable either.

Public Comments

1. No. Vent it out the roof, or straight out the wall with a dryer vent flap.
2. I am not sure what u are calling legal? it is vented to the outside which it is doing. check you local code within your city.
3. The plumbing exhaust pipe is not to be used for anything but its intended purpose. It is used to reliefve the negative pressure in the waste removal system. I know it is difficult but you must find a way to route the exhaust vent independant of other systems. Maybe through the roof.
4. No. If you did the odor might come back thru the fan when it is not running. Vent it to a roof louver or out a gable or soffit.
5. No, it is not legal to connect a bathroom vent fan to a plumbing exhaust pipe. If it is done that way, sewer gases will enter the house through the exhaust fan when the fan is not on.
6. Bad idea, and no it is not to code. The plumbing vent is for PLUMBING.
7. you can buy a roof vent kit at a home depot, lowes etc.. its very easy to install.. just need to cut a hole in your roof.. put the cap flange under some shingles.. apply some roof cement.. its not too bad a job.. i just did one myself for a bathroom that never had a vent fan before..
8. no
9. No, do not connect it to the plumbing vent. Take the exhaust duct from the ceiling fan and vent it separately - they make termination kits to go through a soffit, sidewall, or roof.
10. You really don't want to go this way. Vent it directly out at the wall if you have to.