Does a Laundry Tub Addition Require a Vent Line?
I'm adding a laundry tub next to the W&D but don't see how I can tie into the existing vent system for the washer.
It appears the existing washer drains through the laundry room/garage wall into a 3 inch DWV line coming from the upstairs bath (the 3 inch line is exposed on the back of the garage/laundry room wall). That 3 inch line serves the upstairs toilet and shower. Near the floor of the garage it turns and runs down into the crawl space below the family room where it eventually ties into the main drain.
I thought I read here once that if the fixture arm for an appliance drains into a larger diameter line... then no additional vent is required.
So... could I just use a 1-1/2 inch fixture arm and drain line and run that down into the crawl space and merge it with the previously mentioned 3 inch line that's running sloped horizontal at that point?