||12-25-2007 12:14 PM
DWV in 2x8 ceiling joists
Does anyone know if it is ok to run 2 2" pvc DWV (outside diameter 2 3/8") across 10' of ceiling joists that are 2x8? Someone told me that it is ok if it is within 4' of the end of the joist and is in the upper portion of the joist, but I have 2 2" pipes, one from a sink and the other from a sewage ejection basin. I rather keep them separate until I get to 4" DWV to prevent any potential sewage back-up in the sink. I know I can probably use a check valve on the sink, but would like to avoid that if I can.