Retired master plumber toilet venting design question/problems.

[cacher_chick]

Neither the sanitary tee or the vent take-off can be horizontal.

You can use a wye and 45 or a combo on the trap arm to bring the vent up vertically. The term vertical allows anything between 45 and 90 degrees from level.

[patma]

I think I could. Confused a bit, would not the vent take off in the picture, if turned up 90 work. (I guess not b/c the T is still horizontal.)

If I did use the wye and 45, would the vent be upstream of the wye. In essence, the drain would 180 back to the soil stack?

Pardon the confusion. Tx

[cacher_chick]

It is more a matter of what fittings are appropriate for what use. A sanitary tee is only for use when transitioning from a horizontal drain to a vertical drain. The sweep in the tee must flow vertically downward. It could also be used when combining dry vents on the horizontal, but only above the flood rim of the highest fixture served by the vent.

Here is a picture showing how a wye and 45 or combo fitting is used for a vent take-off. The vent is required to be vertical to ensure that it is not ever likely to become clogged.

[patma]

Thanks for your help. I think I get it now. Per my recent picture, I can replace the S tee w/ a combo wye and turn it up into the wall for dry vent. This should put the 2ft arm below the floor and good clearance.

S trap issue? There is a 3 foot section that is steeper than 1/4 in drop. If I have a vent b-4 this section, that would eliminate the risk of S trap?

The setup: Ptrap>>>2' arm>>>Wye/Combo vent turned up>>>>>>long 90>>>>>4' (steep drop)>>>>Long 90 turned down into stack......

The 2" dry vent upstream from the steep 4 foot section of drain should eliminate the risk of S trap?

Thanks in advance. I truly appreciate your time and help.

[cacher_chick]

You can do whatever you need to in terms of pitch/drop once you are downstream of the vent. The vertical vent only need be 1-1/2".

You are going to need an accessible clean out anyplace your turn exceeds 135 degrees in total.

[patma]

Thank you for your time. I'll add the clean out.