Do ALL drains need venting?

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krosspen

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I'm putting in bathroom #2 upstairs. A freind who knows plumbing better than I tells me I don't need to vent a shower with a 2" drain. Is that so?
 

Terry

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I'm putting in bathroom #2 upstairs. A freind who knows plumbing better than I tells me I don't need to vent a shower with a 2" drain. Is that so?

That is not correct. The shower needs venting.

dwv_traps.jpg
 
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Jadnashua

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To amplify what Terry said, each fixture needs a trap and a vent, but there's sometimes a lot more than one way to accomplish it. In a bathroom group, if you do it right, you can do what is called 'wet venting'. If it is done right, each trap still is getting vented, but there may not be an individual vent line one each of them. THe order, distances, pipe sizes, all play into whether that is possible, but the best way is often to just vent each individually for maximum flexibility later on if you should decide to move things around.
 

krosspen

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Thanks guys, very much. Since we don't know all the factors that allow us not to have a dedicated vent, Im opting to vent the sink and shower (in one) . The fella I'm hiring who is unfamiliar with it must have had all the other things factored in to the plans back when he was doing plumbing.... ten years ago. ONE MORE question.... I see a lot of toilets not vented. We're about 7 or 8 feet from the stack. I'd love to NOT vent the toilet, any advise?
 

Jadnashua

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A toilet can work without a vent. The toilet's trap is IN the toilet, and that is open to the room on top. It gets more complicated when the trap of something else in below the floor or doesn't have its own vent. IF there is anything else on that line before a vented fixture, though, it can cause problems.
 

hj

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There are so many variables when it comes to drains, vents, and traps, that each situation has to be addressed individually. And, you CANNOT "put a bathroom on the second floor" just because that is where the downstairs pipe is.
 

Tom Sawyer

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Whether you vent the toilet or not depends on who's code you are required to follow. Though the IPC lists water closet to vent distance as unlimited, there still needs to be a vent on the system somewhere. You can never use vents from floors below to receive the discharge from fixtures above.
 
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