I am remodeling a 100-year-old house, adding plumbing for a washing machine and condensing dryer. I'm installing the washing machine and dryer in the basement. In the location where I want it to go, there is a 1 1/2" brass waste pipe coming up vertically from the basement floor, about 3 inches or so. The main waste stack is about 2.75 feet away.
I believe I need to install a tee fitting, connect a waste arm to it, connect a p trap to the waste arm and a standpipe to the p trap … similar to the below picture (except with a standpipe connected to the p trap and not a sink).
Questions
How do I connect the tee fitting to the brass drain pipe? Is a rubber reducing fitting OK?
Is my methodology correct?
The p trap needs to be 2" as per code, is it OK that the brass pipe is only 1 1/2" ?
Best Answer
Based on you answer in the comments my answer would be.
Presumably if it was a sink then its vent was provided by the nearby main stack so you should be able to put a san-tee on it and p-trap into the san-tee. BUT it could have had a vent coming of the original san-tee and connecting elsewhere to the stack ?
You want the san-tee low so that you have room enough to put a tall vertical pipe on top of the P-trap so the washing machine discharge does not splash back.
I would, since you do not know for sure if it is vented to the main, stack run pipe up off of the top of the san-tee as high as you can ( at least a foot or more if you can above the top of the top of the washing machine drain pipe ) and put an air admittance valve on top of that.