I bought this house recently with a renovated master bath. Only after I bought it did I realize that the shower drain isn’t connected to the plumbing. When I went to Home Depot to look for pieces to install a p trap to the existing shower drain, I realized that the previous contractor used a no caulk drain that was meant to be used ONLY with a shower pan and NOT a tile shower which this is. This also explains why I didn’t see the protrusion of any waterproof membrane into the drain space, because this type of drain setup isn’t meant to be used with a membrane.
Needless to say, this is all extremely sketchy.
Is there any way to additionally waterproof this shower now that the tile has been laid?
Should I just connect the p trap, start using it, and hope for the best?