I have a pipe cut into the wall in my laundry room between the washer and dryer. My home is 3 years old, and I want to add a sink to the laundry. Is it possible that this pipe is a drain that was plumbed in by the builder? What else could it be? It's about 18 inches off the floor, 2 inches in diameter, right between the washer and dryer. Can I tie my sink drain into this?

Sounds like a washer stand pipe. Do this. Place a rod or broom handle all the way to the bottom. If the end comes back with a few inches of water on it there's a trap down there. You can ot double trap a fixture so you can't drain a laundry sink into it. I would put a coupling on that line and bring it up to 36" off then floor and use it as a washer station.
What you can do is open up the wall, cut a sanitary tee into the washer vent and arm out to pick up a laundry sink. This way the sink eill be vented and the washer wet vented. Sound like a plan? Good luck Tom

Thanks. I should have mentioned that this laundry room is on the second floor. Why would that pipe be cut into the wall with a cap on it rather that just inside the wall?

Why would that pipe be cut into the wall with a cap on it rather that just inside the wall? This pipe is located out side the wall , yes? Where are you draining your washer at the present time? The pipe's capped so debris do bot fall down into it. Let me know if the stick came back with water on it. Regards, Tom

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