I am going to relocate my washer /dryer to the basement below where it currently is located. The current drain is a 2" pvc which I plan on teeing off for the basement drain, keeping the existing location intact in case it needs to be returned to use. My question is, do I need to put an "s" trap in the drain down stairs? I'm sure for gas purposes it should but I wasn't certain of the requirements. If I should, what would be the recommended connections? I guess I mean should I use a T or would a wye be a better way to go? There is also the possibility that I might install a work sink to the left of the washer as well. The vertical drain pipe is going to go down the right side of the washer.
Thanks for any insight.
Don