Hey Guys.
I was asked a question today, on a second floor building that has been converted to 3 different offices, the filing system is where the old washer was (converted hall closet 90 y/o building). The pipes are still there and not going to be used.
The question was if it should be capped if not in use.
IMO, I think it should be to prevent sewer gases from getting in if the traps dry out, which it more than likely is. But before I gave any advice I thought I would throw it out there to you guys.
As a contractor soon to transition to inspecting I agree with capping any and all open drain lines. I’ve worked in homes recently partially remodeled and found unused drains stuffed with fiberglass insulation. Told homeowner and included capping it in my different work, charged only for the part. Cost a wopping $1.35. Worst I ever came across was an old toile drain stuffed with bread bags. Homeowner couldn’t understand why recent bathroom reno stunk all the time.