Referring to the attached sketch, The existing sink drain has a vent that serves both it and the tub. When I relocate my sink, it adds about 4 more feet of length to the distance between the sink/tub vent and the main waste vent. This effectively makes it 10 feet. I believe this is likely too far for code and\or effective performance.

I am afraid that I might have to provide a separate vent for both the tub and the sink which would mean 2 new openings in the roof. Do you see an alternative? I am on the top floor so it is readily doable but I want to avoid/minimize new holes in the roof to the extent possible.

From an operational standpoint, if I were to place new vertical vent pipes for the tub and sink and extend them into the ventilated attic space above the ceiling but not punch through the roof, would that work?


Thanks

Has there been a permit pulled and will this job be inspected? If you're running a 2" vent why not talk the new lavatory vent up and revent back to the existing lavatory vent up in the attic.That way you could do away with the proposed vent. A tub vent can go up in the attic where it can revent back to the lavatory vent and if the original lavatory vent didn't go through the roof it can revent back to a existing roof vent. No extra holes will have to be put through the roof that way. Good luck, Tom