Putting a laundry room on the main floor of a ranch that has a basement. Vertical Vent/soil stack is in the corner of the house. New laundry room is in the center of the house. Distance from washer to stack is 18'. First, do I need to vent the washer drain or is the washer stand pipe providing adequate venting? If it does need a vent, how far from the p trap does it need to be? Second, can I run a 2" drain pipe from the pipe stand of the washer to the vent/stack that is 18 feet away? I've read that the slope cannot exceed the diameter of the pipe and 18 feet at 1/4 inch per foot would be 4.5 inches in slope which is more than twice the diameter of the 2 inch drain pipe. I have master plumbers telling me that it's ok to run this distance and slope with the washer drain pipe. Much of what I've read says otherwise.

Your vent can be 4 inches away from the trap which is 2 pipe diameter s from the trap. In Ma we can go 6 ft max from trap to vent not exceeding 1/4 " per foot. you cant use the stack to vent the washer if there is fixtures dumping from above.

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Thank you! This confirms what I've read about slope and distance.



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