Originally Posted by JeffHerr
I'm no engineer, but is 800 lbs all that much? It's like 4 average men standing close together, right?
I know there's the concern about constant pressure over time, but it won't fall through the floor, right?
The best thing to do is find the carrier beam in the basement, or an outside wall with joists running perpendicular and set the tank up over several joists. That will spread the weight. My 150 runs with the joist and the right end is 6 ft in on the middle of a 12 foot span, the worst possible situation.
I put a 20,000 lb. jack post under the joist on the right end. Over a period of about a week I leveled about a 1/4" of sag out of the joist and now there are no worries!