I am venting a kitchen island sink. Is there a limit to how far you can run horizontal to connect to the main vent stack after you have run your loop vent under the island?
I may have answered my own question.
It seems the max. horizontal run after the loop vent is 6 ft for a 2 in pipe. Does this sound about right?
"I may have answered my own question.
It seems the max. horizontal run after the loop vent is 6 ft for a 2 in pipe. Does this sound about right?"
No. It doesn't sound right. There should be no limit at all for the length of a horizontal run or 'foot vent' that gets connected to a main stack.
The only limit in most cases would be on the horizontal length of the trap arm between the sink trap and the island vent itself...which is limited to 8 feet for 2" pipe.
See the links below for how Code compliant Island vents should be installed under most codes:
If your kitchen island vent doesn't look like the above diagrams, you're not installing the island vent properly.