DWV Venting Question

[Ntcarson]

I'm working on a project house, circa 1950, and decided that I'm going to do a full plumbing replacement. While I have a solid understanding of most plumbing code, I have a (probably) stupid question:

As long as the proper number of units are served and the vent origination is within spec, can multiple vent pipes be brought together to the main vent stack in the attic? Motivation - avoid adding more penetrations to the roof, mostly; take advantage of the close proximity of the additional bathroom.

If yes - why is this not done more often?

Thanks!
Neil

 

[John Gayewski]

Yes you can attach a lot of vents together. It's not done usually when there's a reason it can't be done easily. Why would you run another hundred feet of pipe if you can just poke up out of the roof? Especially since roof pennatrations are not a big deal, there's not much reason to run pipe across a building when you don't need to.

 

[Sponsor]

 

[Ntcarson]

Yes you can attach a lot of vents together. It's not done usually when there's a reason it can't be done easily. Why would you run another hundred feet of pipe if you can just poke up out of the roof? Especially since roof pennatrations are not a big deal, there's not much reason to run pipe across a building when you don't need to.

Thanks John - that's what I thought; I appreciate it! In this case, they are just vents from 3 bathrooms in very close proximity. For me, a couple extra feet of pipe and a couple joints in the attic are much more convenient than another hole in the roof.

 

[John Gayewski]

Usualy the kitchen isn't that close to a bathroom so a kitchen will have it's own pennatration. People are building more bathrooms than bedrooms nowadays so they can be really spread out. It used to be people would design to have the all of plumbing near each other but the designs are getting more based on god knows what.

 

[Ntcarson]

Usualy the kitchen isn't that close to a bathroom so a kitchen will have it's own pennatration. People are building more bathrooms than bedrooms nowadays so they can be really spread out. It used to be people would design to have the all of plumbing near each other but the designs are getting more based on god knows what.

Agreed! Unfortunately, for this kitchen, I'm going to have to use AAV due to sink in island...

BTW, where are you in IA? I grew up in Sioux City and did undergrad at UIowa.

 

[John Gayewski]

Agreed! Unfortunately, for this kitchen, I'm going to have to use AAV due to sink in island...

BTW, where are you in IA? I grew up in Sioux City and did undergrad at UIowa.

Burlinton an hour away from u of I.