I believe that you are correct, Allan. Usually apartments use truss style floor joists. Not very many houses use those. It also depends on the placement of the tank. If you have it against an outside wall vs. standing alone. Typically you can count on finding the shortest run of a room's joists as load bearing. I put a 55 upstairs and sold my 125 because the way my joists were. I would've possibly overloaded the joists past a structural design factor meaning they might've not collapsed but would've shorten the expected life of such.


- Ben -