I'm not trying to slam you here, but are you a licensed master plumber, or at least a journeyman? I would guess not (since you were painting signs later?) so what were you doing working on plumbing? I am a licensed master plumber, and for a building of this size, how did you get to work on anything with a domestic water connection? I'm guessing no inspectors were involved!
Again, not trying to be snippy to you, but that's a total apprentice mistake. Oh well, at least it worked out. Glad the building didn't flood or a fitting blow apart as I'll bet your insurance wouldn't cover it if y