basement bathtub install - morter patch

I am finishing my basement, and will be installing a two or three piece tub / shower. My basement has been roughed in. There is a 2 inch pipe sticking out of the cement floor for the tub drain. Should there be a morter patch that I need to chip out in order to properly install the drain and overflow?

Also, do I need to install aqua board behind the tub and shower, or can the 3 piece shower simply be attached directly to the studs?

thanks

2" line is required for a shower. 1-1/2" line for a tub. So, it may have been plumbed for a shower instead of a tub. Not a big problem, but yes, you need to probably tear out a little bit to see what's there, and you'll need a fitting to make the sizes match up. It would be rare that the pipe was exactly where you wanted it, so tearing out a little will allow you to accommodate the tub drain. You need to verify there's a trap in there, and after you get things checked out, you might go with a 1-1/2" trap - it might give you a little more leaway verses the bigger one.

No need for anything on the walls although you may want to put up a vapor barrier. Most of those that I've seen are designed to bring the drywall down over the flange of the enclosure.

2" is a minimum pipe size under grade. It could be either a tub or, a shower drain. Size would not be an indicator here. Placement would be! Is the placement where a tub drain would land or, a shower drain?