Wet venting a toilet

[branimal]

I am running a horizontal toilet line and I don't have enough height in the joist bay to attach the closet elbow to a santee to dry vent. I'm able to vent the adjacent lavatory with a 2" vent pipe. Can I connect the lav drain line to the toilet line (3x2 wye) to create a wet vent?

Here's a diagram:

 

[Twowaxhack]

I am running a horizontal toilet line and I don't have enough height in the joist bay to attach the closet elbow to a santee to dry vent. I'm able to vent the adjacent lavatory with a 2" vent pipe. Can I connect the lav drain line to the toilet line (3x2 wye) to create a wet vent?

Here's a diagram:

That’s what I would do.

 

[branimal]

That’s what I would do.

Thanks.

I've got a couple more questions:

1. I have the same question for a bathtub and kitchen sink. Can the bathtub be wet vented as per my diagram below?
2. How do you support horizontal runs of drain on the parallel joists? I am working from so I can't screw into the flooring above. See pic.

Btw, I ordered the hub and spigot 4x3 closet bend you recommended. I'm test fitting with the 4x3 street closet for now.

 

[Twowaxhack]

I wouldn’t wet vent a bathtub with a Ksink.

For support install some blocking. You can also get plastic strap made for securing piping.

 

[branimal]

I wouldn’t wet vent a bathtub with a Ksink.

For support install some blocking. You can also get plastic strap made for securing piping.

Is the water flow from a kitchen sink (dishwasher) too much for the bathtub to vent properly? I never really understood when wet venting is allowed and when its not.

This is a 3-bedroom apartment with potentially 3 strangers living together. It's possible that someone is bathing and another person decides to run the dishwasher.

 

[Twowaxhack]

It’s determined by fixture units assigned to the fixture and the type fixture.

I call it a major fixture over a minor fixture. Can’t do that……

 

[branimal]

It’s determined by fixture units assigned to the fixture and the type fixture.

I call it a major fixture over a minor fixture. Can’t do that……

Ok I sort of understand the concept now. The amount of water being drained from the lavatory is less than what the toilets vent size (2") can handle. Hence no siphoning action. Lav fixture units (1) < Water closet 1.6gpf (3).

But when a bathtub's vent (fixture unit =2 ) is draining a kitchen sink (fixture unit =2 ) OR a dishwasher (fixture unit =2 ) this is a no go b/c 2=2.

Is my interpretation somewhat accurate?

Here are the charts I found.