Toilet Drain

[Arky217]

Which of these is the best configuration for a toilet drain ?

Going to assume that C is incorrect because of no immediate vent pipe; that leaves A or B.
Which one would be the best configuration ?

Thanks,
Arky

[flyingvan]

'B' is, at least around here, typical

[Redoverfarm]

Generally "B" but "A" would IMO be better because there is less chance for clogs which would block your vent stack.  I guess we don't have a resident plumber.  Is there other fixtures in the bathroom that also need vents.  So maybe in tieing those your thoughts might change.

[alex trent]

Found this site...a training course.

Has some simple and useful explanations and readable diagrams on the basics.

http://www.gpta.net/Classes/Venting/Venting.pdf

[metolent]

At first I thought I did both A and B in my build, but after looking back through some pics, it was only two of the B configurations.  But then I don't have a "main" stack that is 3" all the way to the roof either.  That's what I originally planned and when the inspector and I walked through what I planned to do before I started the plumbing, he indicated that was no longer necessary.  So, one of my toilets has a 1 1/2" vent (the minimum for a toilet by code) which is later tied together with the other vents from the bathroom.  The other toilet has a 3" drain as well, but I necked that down 2" vent - a bit larger to handle the laundry as well.  They make a sweep 90 with a heel for venting that I used in both cases.

So for reference, I have a total of 3 vents going out my roof.  One 1.5" vent for the kitchen sink (separate only because it's some distance from the bathrooms), one 1.5" vent that picks up the toilet, bath sink, and shower for the downstairs bath, and one 2" vent that picks up the upstairs bath (shower, toilet, 2 sinks, and laundry).

Figuring out the right way to do the DWV plumbing was one of my biggest mental exercises.  Hope that helps. 

matt

[Arky217]

In the following picture, assuming that the 'other drainage' pipe cannot be moved, which would be the better arrangement, A or B ?

Thanks,
Arky

[flyingvan]

AS long as 'other drainage' isn't another toilet, I'd go with 'A'.  Shorter run for the big volume for one.  You're wet venting only liquids, two.  It'll be easier to snake a clog from the toilet, three.

[Arky217]

One last time on the toilet drain.
Because of obstructions and space limitations, I need to have the toilet drain into the
stack lower than the tub and sink.
Would there be any potential problems with this arrangement, that is, having the sink and tub drain into the stack about a foot above the toilet inlet ?



Thanks,
Arky