Can you guys double check my drainage?

[hj]

quote;

Why do folks think that floor joists are optional?

Probably because onc the floor is put down, nobody will see it.
Saying it is "not load bearing" ignores the fact that the tub's apron will be sitting almost directly over that "compromised" joist. I am not sure what that "stuff" is. It could be lead wool which I have never been able to use and not prevent a leak, or some sort of "plastic lead" putty. I doubt that it is a "poured" lead joint since that would have melted the PVC pipe.