I am building a custom shower in my basement. The plumbing rough out for a basement bathroom was done during original construction. My question is this... Do you need a P-Trap for the shower drain? What I have right now for plumbing is a 2" PVC stubbed out and capped in a hole cut into the concrete with gravel in the hole and around the PVC. Is it appropriate to use a 90 instead of a P-Trap?

I am building a custom shower in my basement. The plumbing rough out for a basement bathroom was done during original construction. My question is this... Do you need a P-Trap for the shower drain? What I have right now for plumbing is a 2" PVC stubbed out and capped in a hole cut into the concrete with gravel in the hole and around the PVC. Is it appropriate to use a 90 instead of a P-Trap?

What you have is a tub dap out. If there is just a horizontal drain line with a cap in the hole you will have to cutthe cap off and install a 2" "P" trap and a raiser that will extend about 3 inches above the floor line. Will this be a custom tile shower or a plastic/fiberglass shower base? Let me know before you do anything. Regards, tom

Thanks for responding. This will be a custom tile shower.

Thanks for responding. This will be a custom tile shower.

That's good. Then you won't have to position the drain to accept a shower base. Cut the cap off and prime and glue on a 2""P" trap making very sure it's level. Now install a raiser from the trap to 2 or 3" above the floor line.
Now fill and cement the tub dap out. You may now frame out the shower and threshold and then set the flange type shower drain, (see image).
Let me know if you need help with the rest of it. Tom

Thanks Tom-

Now I need to ask you a follow-up question. I have the flange type drain you pictured. I intend to put down the waterproof membrane directly on the basement slab. Should the flange be flush with the basement slab and the part that screws into the flange is my space for tile width? I was a little confused by your suggestion that the riser extend 2-3 inches above the floor line.

"I was a little confused by your suggestion that the riser extend 2-3 inches above the floor line"

I just wanted to make sure that the raiser had enough stock to glue the flange type drain to. Set the flange over the raiser and mark and cut it.
The flange will set on the floor and yes, you will set the drain to the slope you wish and mortar and tile level with it. You will pan out using Blue Compaseal Plastic with seamless corners and with the walls of the pan ran up 8". Good luck, Tom