In my roof attic I have a 2" kitchen vent just inside the attic on one side of the house, the main 3" stack which vents out through the roof is on the opposite side of the house. They are about 24 feet apart.
Can I connect them or is there a restriction on a vent pipe distance to a stack?
Best Answer
The only things that should limit you are number of fixture units being vented (dfu), and the required slope of horizontal vent pipes (1/4" per foot for 2" pipe).
Drain Fixture Units
If too many fixtures are being vented by this vent, the size of the vent will have to be increased.
Since it sounds like you're venting a residential kitchen, there's likely only a sink. So you'll probably not have a problem with this.
Grade
Vent pipes must be graded and connected, so that they drain back to the drainage pipe by gravity. Which means, any horizontal sections of the 2" pipe will have to have a slope of 1/4" per foot toward the fixture drain.
This could be a problem depending on the surrounding structure, since the pipe will be 6" higher at the stack end.
1/4" * 24' = 6"