Hello All...

Looking for comments on these two schematics for a plumbing layout that cuts into a cast iron 4" sewer line out to a septic system. The reason for the change is a VERY small bathroom is being expanded (12" from toilet bowl to tub!).

You'll note that despite a very small space (still)...I'm planning on three vents (1.5" for a 3" toilet, 2" common vent for kitchen sink/shower, and 3" as lav sink/main stack vent).

There is an offset in this system that is greater than 45 degrees but doesn't appear to be a problem for the fixture values of the proposed load (about 15 FUs).

The reason for a separate vent for the toilet is my concern about running close to 8ft to the now offset main stack and a risk of siphoning from the tie-in with the shower. That is why the venting overkill.

The 1.5" and 2" vents would tie-in to the 3" vent via a vent header in the attic and then exit the roof via that 3" vent.

Lastly....remember that Massachusetts doesn't follow IPC or UPC but has it's own code...248 CRM 10.

The schematics SHOULD be compliant with those requirements, but I'd appreciate thoughts from those well versed in this code. For instance, note the kitchen sink (while a dedicated drain per code) feeds into the main stack BELOW the toilet and shares a common vent. I'm assuming all that is OK. Please note that also per code, that tie-in is within 10" center to center of the piping above it.

OK, hopefully these drawings make sense (and will load correctly. Not used to a non-GUI interface for image uploads). Thanks for comments, thoughts, and critiques.

Ryan.

[i.imgur.com]

Packy will probably chime in, but normally the toilet would need a 2" vent, you do NOT show how the shower will tie in to the "common vent", and it should all be immaterial, because in MA you CANNOT do your own plumbing, so whoever you hire to do it will do it HIS way, regardless of any drawings you create.

Good luck with the work, man.

Looks pretty good. I'm not a Mass guy, so I don't know all of the specifics there...



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You REALLY like the shower connecting to the toilet discharge without any vent indicated?

you do realize you can not do your own plumbing in MA???
anyway..
if the toilet is within 7 ft of the stack it does not need an individual vent.
if the shower is within 6 feet of the stack it too can be drained into a side inlet sanitary tee and no vent needed. it and the toilet will be stack vented.
the kitchen does need a vent but will have to tie into the stack not the toilet pipe. the lav as shown is correct.
BUT.. without a side view with specific distances all my advice is just guesswork..

Thanks Packy. Appreciated.



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