Using Double Sanitary Tee arms for drain and vent

[ccarrasc]

I am having to re-plumb my bathroom, and am trying to follow IPC 2018 as best I can (I live in Vermont).

The current Stack Vent, which exits the roof, is 3" copper and currently only vents the toilet. As I am now replacing the toilet, and remodeling the bathroom, I figured it was a good time to open the wall and tee off the stack so the other fixtures can be vented. This is a single story home with a basement.

The part I am having difficulty with is where the sink drain is entering one side of the Double Sanitary Tee, and the toilet vent on the other side. Is this a correct way of venting? If so, what vent type would this be considered? I thought it resembled a "Common Vent", but I am not sure if the toilet vent side is considered wet when the sink drain is at the same level...

The design is rough, where the pipe lengths are for illustration purposes only. But the fittings should be according to the IPC (I hope). Here is a link to the design: https://make.craftyamigo.com/design/XhYmlsfUlTO7OuIhAAuxL5gISfq1/boyC6AeRJbU9ap56pBVb

From another angle:

Any thoughts or observations would be appreciated.

 

[Jeff H Young]

dont need the vent for w/c the lav will be its vent. vent from the tub works PROVIDING the vent rises vertically aprox 42 inches (6 inches high above sink top) minimum befor going horizontal or connecting with another vent.

 

[Sponsor]

 

[ccarrasc]

dont need the vent for w/c the lav will be its vent. vent from the tub works PROVIDING the vent rises vertically aprox 42 inches (6 inches high above sink top) minimum befor going horizontal or connecting with another vent.

That would simplify things

If I understand correctly, the sink would be 2 dfu, and 1.5" pipe allows for 3 dfu, so I should not have to size up the portion that is wet vented to 2", right?

The tub vent would run about 55" above the sink before going horizontal.

 

[ccarrasc]

That would simplify things

If I understand correctly, the sink would be 2 dfu, and 1.5" pipe allows for 3 dfu, so I should not have to size up the portion that is wet vented to 2", right?

The tub vent would run about 55" above the sink before going horizontal.

View attachment 99808

Ah, I found the reference to the wet vent size in 912.3 - it should be 2".

 

[Jeff H Young]

Ah, I found the reference to the wet vent size in 912.3 - it should be 2".

Ah, I found the reference to the wet vent size in 912.3 - it should be 2".

Actually the tub vent can be only 6 inches above rim of bath tub and rise verticaly anywhere to the 55 inches you mentioned at the tie in point justthe way you have it drawn looks like you want to keep it low

 

[wwhitney]

If I understand correctly, the sink would be 2 dfu,

A lav is 1 DFU. The IPC would allow the diagram below (ignore the white pipes), where the lav first wet vents the tub, and then the combined drain wet vents the WC. Green is 1.5", blue is 2", red is 3".

[For jurisdictions using the UPC, the same diagram would work if the green excluding the trap arms is upsized to 2", and the length of the piping from the closet flange to the 3x3x2 wye is 6' or less.]

Cheers, Wayne

 

[Jeff H Young]

A lav is 1 DFU. The IPC would allow the diagram below (ignore the white pipes), where the lav first wet vents the tub, and then the combined drain wet vents the WC. Green is 1.5", blue is 2", red is 3".

[For jurisdictions using the UPC, the same diagram would work if the green excluding the trap arms is upsized to 2", and the length of the piping from the closet flange to the 3x3x2 wye is 6' or less.]

Cheers, Wayne

View attachment 99849

That saves a few fittings and work. Seems a bit cheezy all 1 1/2 pipe but works IPC as far as I can tell!

 

[ccarrasc]

Actually the tub vent can be only 6 inches above rim of bath tub and rise verticaly anywhere to the 55 inches you mentioned at the tie in point justthe way you have it drawn looks like you want to keep it low

I misread your original comment. You are correct - I messed up and should have the vent for the tub much much higher than illustrated.

 

[ccarrasc]

A lav is 1 DFU. The IPC would allow the diagram below (ignore the white pipes), where the lav first wet vents the tub, and then the combined drain wet vents the WC. Green is 1.5", blue is 2", red is 3".

[For jurisdictions using the UPC, the same diagram would work if the green excluding the trap arms is upsized to 2", and the length of the piping from the closet flange to the 3x3x2 wye is 6' or less.]

Cheers, Wayne

View attachment 99849

That is a pretty clever alternative. Thanks!