MIA vents Question

[Anonymous]

Under good plumbing practices a vent should be located with in 24″ of the trap and the trap within 24″ of the fixture horizontally and 48″ vertically.

Considering most toilets have an integral trap the closer to the fixture the vent is located the better. Good luck and it was a great question.

[GuestParticipant]

Syvlan–Thank you for your answer. I really appreciate your taking the time to write and I’ve enjoyed reading your responses to other posters as well.

Given your answer, I probably can’t count on going in through the closet floor, but I think I can do it through the floor under the vanity so it won’t show.
I hope you don’t mind answering two more questions.

The toilet is the only trap on that 3″ drainpipe. I know I need 3″ of ventpipe, but I don’t want to run 3″ pipe through my 2×4 wall if I can help it. Can I vent the same trap twice (once with 2″ pipe and once with 1-1/2″) and join them to a three inch pipe in the attic…

Also, I know each fixture is supposed to have an individual vent….if only some are vented, do you at least get some benefit, or does it make the problem worse??

P.S. Figured you’d be happy to know that the Studor vent is illegal in my area.

[SylvanLMPParticipant]

quote:

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Originally posted by HelpMe:
Syvlan–Thank you for your answer. I really appreciate your taking the time to write and I’ve enjoyed reading your responses to other posters as well.

Given your answer, I probably can’t count on going in through the closet floor, but I think I can do it through the floor under the vanity so it won’t show.
I hope you don’t mind answering two more questions.

The toilet is the only trap on that 3″ drainpipe. I know I need 3″ of ventpipe, but I don’t want to run 3″ pipe through my 2×4 wall if I can help it. Can I vent the same trap twice (once with 2″ pipe and once with 1-1/2″) and join them to a three inch pipe in the attic…

Also, I know each fixture is supposed to have an individual vent….if only some are vented, do you at least get some benefit, or does it make the problem worse??

P.S. Figured you’d be happy to know that the Studor vent is illegal in my area.

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Fantastic finally real professional NON graft taking inspectors or building officials IMHO AMAZING

You do not need a 3″ vent pipe for a 3″ soil line.

Your venting should be sized by developed length and fixture units connected

For example if I used a 4″ soil line for a toilet I would need a 2″ vent BUT considering I can legally use a 3″ line the code will permit me to use an 11/2″ line depending on the developed length of pipe and fittings.

Check your local code book.

Also most of the better codes do require ONE VENT STACK full 4″ diameter to pass through the roof BUT there are some provisions where if you run a 2″ vent line just below the roof you can increase it to 4″ to prevent “Hoar Frost.”

Check your local code and most of the time by using these piping arrangements you are exceeding the local requirememts.

You just may have to explain to the inspector WHY you increased the vent piping as not all code officials are created equal..

[Author]

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