I have a utility sink in my walk-out basement - that sink's 1.5 inch drain connection is approx. 18" above the floor, into a two inch horizontal run. This 2 inch horizontal PVC runs about 3 feet, then connects to a main 3" DWV. I would like to add a bar sink, set into a standard height (36") countertop, into this basement area. The stub-out for this sink would be about 8 feet from the utility sink drain connection point (further away from the main DWV stack).

Two questions - 1) Considering a 1/4'-per-foot fall on this new 8 foot extension, my stub-out for the new bar sink will be at about 20" above finished floor. Is this low enough? And 2) Can I simply install a 2x1.5x1.5 "T" at the utility sink stub-out and extend 1.5 inch pipe eight feet to accomplish this - without adding another vent line connection?

Hey Don,
"Two questions - 1) Considering a 1/4'-per-foot fall on this new 8 foot extension, my stub-out for the new bar sink will be at about 20" above finished floor. Is this low enough? And 2) Can I simply install a 2x1.5x1.5 "T" at the utility sink stub-out and extend 1.5 inch pipe eight feet to accomplish this - without adding another vent line connection?
(1) It would be a little tight but still doable. Figure about a 8" drop from the 36" countertop leaves 28" from the floor. At 20" to the center of the stubout to the floor leaves you 8" of "wiggle room".
(2) Nice try but no cigar! The farthest you may extend a 1 1/2" drain line from trap to vent is 3 1/2'. At 8' out you'll have to revent back into the utility sinks vent. Good luck, Tom

Thanks for the response, speedball. Hopefully that "wiggle room" will give me enough space for the drain connection. Sad to hear about the revent, though... more work for me - but I'll do it right to forego future problems.