the basement rough-in was completed with a shower/tub rough-in. I want to convert it to a shower. I bought an alcove left drain fiberglass tub. The shower does have a p-trap and everything should be vented already. To install the shower drain, do I just need to cut the tub rough-in below the contract and add two 45 street elbows to where the permanent shower drain will be?
That pipe that is pictured above the floor may be the beginning of a vent pipe. Yes it does look like there is a trap below the floor, from what I can see, a little more dirt removed would have been good, but it looks like it is there. If the tubs bottom is high enough, you will not need to remove more concrete, the drain of the tub can set above the concrete floor, most tubs do not allow that. Most likely you will need to break out about 8-12" more under the tub to set the drain. Typically the trap is glued in last so the pipe from the overflow and tub drain is a straight shot down into the J bend of the trap. With the way it is assembled now, you will need to add a few otherwise unnecessary elbows to get it to connect. If you leave it that way add a clean out real close in case it clogs. More elbows equals easier clogs.