| Hi Andrew,
If this were a basement project I would say that I can find no fault with your idea. Just break the cement up, install a floor drain and slope to it. However, your last sentence .( "Oh I'm also on the second floor so it all needs to be water tight.") put the kabosh on that.
Being on the second floor will require you to install flange type shower drain,(see image) and a shower pan before cementing. The reason for this is that some water is bound to seep past the drain no mater how much water proof paint you slap on it. With just a concrete base and a drain this water has no place to go but down through your ceiling. The shower pan will catch this leakage and the weep holes in the flange type drain will divert the seepage back into the drain line. Do you need instructions on how to pan out your shower? Regards, Tom |