Basement Rough In- how much re-work?

We recently purchased a home that was built in 2006. The former homeowner was in the process of finishing his basement. I want to continue where he left off but I'm puzzled by the bathroom setup he has. In the picture there's a 2 inch pipe coming from the floor that has water roughed in above it. To the right is a boxed in hole in the cement with another pipe about 8 inches down.



Not in the picture is a rough in for the toilet and behind that a rough in for the sink. (Water and waste.) Since it was roughed in during construction and built only in 2006 I would think that it is already wet vented thru the lav. However, the 2 inch pipe that the guy has setup as a bath tub drain gives me pause- is that really a tub drain or is it the vent that needs to be hooked up? Based on the walls he has, it's built for a tub/shower unit. If the 2 inch pipe really is a drain (It's 23 inches from the back wall) then I'll need to build a wall to shorten up the distance...not a big deal. However, if it's a vent then I've got a lot more work to do.

Any thoughts?

Tub or shower, either way, the construction is wrong, because EITHER one should be installed before the sheetrock, and that is the wrong wall material for either one anyway. If it is the drain, then there will be a trap under the floor with water in it. WE would also need to see that pipe in the "box" to get some idea of what it COULD be and why it has a box over it.

Thanks- updated rough in picture

HJ- thanks for replying. I dug up the sand and found another 2 inch pipe about 6 inches down. I also broke the cap on the 2 inch pipe sticking out. There wasn't any water but when I poured water down it I could hear it pool at the bottom. I also looked down with a flashlight to confirm that the water was staying.



So it sounds like I need to remove the sheetrock for starters. Since the drain pipe is 23 inches from the wall I would either need to build another wall closer in or move the roughed in tub shower faucet to the other side of the wall to utilize the rough in that is boxed into the cement?

Pull the cap off the 2" riser, and pour some water in it... maybe you have a trap there, maybe not.

Personally I think it is crazy to bury a trap in concrete.

Also, in some multi-family homes drywall behind the tub would be required for fire-rating...

Go shopping for a tub/shower/pan whatever it is you're after, and you can decide how to modify the rough in based on the dimensions of what you choose.