Thank-you for this forum. We are considering plans to move our laundry appliances from the first-floor to the basement. Currently there is a utility sink in the basement that could potentially be used for the washing machine disharge hose, however, we would like to re-locate it. Can we use the existing DWV configuration on the current utility sink for the same sink that will be located approximately 12' from the main 3" DWV stack? We would have to run a section of new PVC pipe from the re-loacted sink to the 3" main stack. Photos of the utility sink trap and the 3" main DWV attached.
You will have to raise the sink a little higher to maintain 1/4" per foot slope. Drum trap should be replaced with a P trap.
Biggest problem...I don't think you have a vent at all. I suspect that 4" vertical pipe is a waste stack.
Thanks..hammer..... very nice drawing and table.
Last edited by Terry; 04-22-2012 at 11:24 AM.
Correct..the current sink configuration does not have a vent other than the 3" main DWV stack (wet). I would have to add a vent line (1 1/2") to the 2" waste line for the re-located sink and washer drain stack. Not an easy task as the closest dry vent line (1 1/2") that I can tie into would require an approximate 26' horizontal run along the basement ceiling before making it's vertical run through the first and second floors. Would this be a problem? Is there a required pitch for a horizontal vent line? Also, I would consider adding another sanitary tee below the exisitng tee (picture in original post) that would accomodate the trap line from the re-located sink and drain stack. This would get me the required 1/4" per foot of slope without having to raise the sink.
You can't wet vent between floors. The waste develops too much speed down the pipe for that to work.
Wet venting is for bathroom sets, on the same floor. You don't drop toilet waste over anything. That's called siphoning the p-trap, not venting.
Install an AAV on the trap arm, at the least.
I would not use the 3" main DWV line (pictured in original post) as a vent line for the re-located laundry sink and drain stack. I have access to a 1 1/2" dry vent (currently the vent line for the laundry drain stack on the first floor) in the basement ceiling, however, I would need to make an approximate 26' horizontal run along the basement ceiling, from the re-located sink and laundry drain stack to the exisiting 1 1/2" dry vent line. Would this vent pipe horizontal run be a problem?