venting toilets

I am a licensed plumber in California where we go by the 1997 UPC. When I install a typical residential drainage system in a crawl space before subfloor is laid, I usually vent the toilets as follows: the 3" line desends vertically from the toilet to a 3" combo @the building drain or branch thereof. Just downstream or upstream of the combo I install a 3x2 sanitee for venting with the branch vertical or rolled no more than 45 degrees. I have used this method for many years and been inspected by many inspectors, but now an inspector has called out for all the sanitees (3 for toilets and 2 for showers) that are used in this manner be replaced with combos or other drainage fittings. I have talked with 3 other inspectors in other towns and they all agree with me and say it's common practice. The UPC doesn't say I can't use this method, but doesn't directly say I can. The UPC Illustrated Training Manual does not have a picture exactly like this method but I did find one in the 1982 manual. I am 99% sure I'm right and am looking for more proof or advice on how to proceed.

Emm Let Me Think. Bingo

You must have Dan shea on your project in S.F.

Not sure if I'm following what you're saying but around here the rule is that a sanitary tee can not be used on it's back....must use a combination and a drain rolled on it's side can not be more than 60 degrees on it's side. We were doing a 6" cast iron drain where the inspector insisted that we pull out two 45's and put 18" between the gland packs connecting them. Everyone on the job thought the two 45's would be fine just like a "long sweep".

The only pertinent paragraph I find in the 2001 California Plumbing Code ( based on 2000 UPC ) is 905.2, and I don't see that it prohibits connecting a VENT in the manner you described:

905.2 Where vents connect to a horizontal drainage pipe, each vent shall have its invert taken off above the drainage centerline of such pipe downstream of the trap being served.

vents



I cannot imagine an inspector approving a vent installed like you describe, because it seems to be venting the horizontal run, and only vents the toilet as an incidental thing. The rule we go by is that any fitting below the flood rim of a fixture has to conform to the requirement for a liquid drain, which means no sanitary tees in a horizontal run, or short turn 90's, etc, below that level.

I think hj is right that they seem to automatically fail a san tee on its back, even though in this case, it is not draining a fixture, the take off is vertical, and logic does not indicate why this woudn't work. Oh, well, that's why I don't get to be the inspector!


A combo fitting to vent on the horizotal