I live in a coop apartment and am remodeling my kitchen. The plumber tells me that the current plumbing is not up to code (nyc) because the kitchen sink does not have its own vent. I checked behind the wall and the sink drain connects to the main stack at a distance of less than 2 feet. Might there be a limit on the number of fixtures connected to the main stack. Currently 2 bathrooms and the kithen sink drain/vent to the main stack. All runs are less than 5 feet as the bathrooms and kitchen are placed contiguosly in the apartment.
I don't understand why the kitchen sink would need its own vent. Thanks.