Venting question.

[ROBERT V. YOUNG]

Obvious but tired.
3.5 bathrooms and i vent stack.
Attachment 47501
What makes it worse is 2" inch ( master bath ) PVC is taped into a 2" PVC off tyhe main 3rd floor bath, then expanded into one 4" PCC 12 inches before the exit through the roof deck.
Washer dry , powder room with shower cabinet.
1/2 bath on first floor.
Kitchen with island and double sink.
Attachment 47502
here is the 4" enlarged PVC fitting and exit.
Attachment 47503

[Roy D. Cooke, Sr]

Not proper and not allowed you can end up with a bath exhaust discharge circling in the home and none of the moisture vented to the out side .

All require there own discharge to the out side .

The 2 inch is just another incorrect concern .

Roy

[ROBERT V. YOUNG]

Originally Posted by rcooke

Not proper and not allowed you can end up with a bath exhaust discharge circling in the home and none of the moisture vented to the out side .

All require there own discharge to the out side .

The 2 inch is just another incorrect concern .

Roy

http://www.3dplumbing.net/ontplumbing/vent_stack.htm
Take a look.
Engineered vent stacking.
Attachment 47511

[Roy D. Cooke, Sr]

Sorry I was still a sleep I thought you where talking about Bath room and Kitchen power exhaust vents .

[Marcel Gratton]

Robert,

The black pipe is ABS and increase to 4 inches in unconditioned area to prevent frost closure.

[ROBERT V. YOUNG]

Originally Posted by mgratton

Robert,

The black pipe is ABS and increase to 4 inches in unconditioned area to prevent frost closure.

They covered the ABS stack with galvanized as it exited the roof.
Metal will conduct cold faster than ABS.
No main waste ( wet stack ) in the attic. Only venting.
The main wet stack can not be seen Marcel.

That is the only venting exiting the roof.
I thought the main waste or wet stack must continue through the unit exiting the building through the roof, not the wall.
Link please.

[Robert J. OConnor]

Individual fixture vents need to be at least 1-1/4", branch vents need to be at least 1/2 the corresponding branch drain size and sized for the drainage fixture units (typically 2" pipe), there needs to be at least one vent thru the roof, and the size of the vent on the exterior needs to be at least 3", where subject to freezing, with that transition at least 12" below the room. See IRC Chapter 31 or Code Check for an HI's POV. Your local mileage may vary ...