Is critical distance measurement based on the literal distance from a trap to the vent stack, or the total length pipe from the trap to the vent? In other words, if the trap is 4 feet from the vent, but the drain pipe from the trap to the branch that has the vent connected to it is 10 feet, is the distance from trap to vent 4 feet or 10 feet?

Thanks.

Hey Dave,

The distance between trap and vent is the total "developed length" so the distance would be 10 feet. Section 1409.3 in the Standard Plumbing code Book addresses this. Would you like the different measures between trap and vent or do you have them? Regards, tom

I thought so, but was wishing for the other. Thanks!