Tank placement question - Any engineers out there?


New member
I live in a townhouse and have a question regarding tank placement on the second floor. Hopefully I can explain this without a drawing.

Tank is 72" x 24" x 18" tall (water level is more like 16.5"). Sump holds about 35-40 gallons so that puts the tank at around 150 G total.

The place is open concept so the second floor is basically a large rectangle (roughly 40' x 20')and the floor joists are parallel to the 40' wall. Underneath the side of the room that will have the tank is the garage and about 11' into the length of the garage there is a beam running across the 20' width which I think is made from 4 - 2x10's. Then roughly another 10' is the interior garage wall which I believe to be load bearing. So the floor joists are supported by a beam and a load bearing wall.

I hope that makes sense.

I want to put the tank across as many beams as possible but I can't put it on one of the outside load bearing walls because they are all windows. The best spot is against a partition wall which is directly over the beam in the garage. So the tank would be near that beam and over about 4 floor joists. I am wondering if this is a good idea?


New member
I was in a similar situation and the only place to put my tank was along a loadbearing wall right on top of another loadbearing wall. Still, it was scary, especially with the very real possibility of an earthquake striking at any time.
After we moved I set up my tanks in the garage... and added an additional wall of six 40Bs.

Your tank is going to weigh in at roughly 2/3 of a metric ton plus the people that might be standing in front of it. So best is to assume at least a full ton. An otherwise unsupported beam may not be enough for such a mass. You will either have to find a different spot, add support column(s) for the beam(s), or scale down the tank.
One additional option would also be to place the sump next to the tank instead of underneath it. That way you could spread out the weight a bit more.
Your best option would probably be putting the tank in the garage as I did... far from ideal but also less restrictive.

If you are really going to put the tank on the second floor I would definitely consult with an expert to make sure your floor can handle the additional weight of the tank on top of everything else.


New member
i think i understand the description but maybe a picture would be better. It sounds like thats fine.

There will be more than a ton for sure, dont under estimate that.
1 251.81 pounds of water weight alone.
consider, sand, stand, pumps, tank.... it adds up very quick.

engineers will most likely be WAY conservative so take that into consideration. If you can see how many joists your tank can span that would help too. Making sure you take full advantage of it.

Personally i worried WAY too much about it and just ended up doing it. Mine is perpendicular to the joists, against the load bearing center wall which directly underneath (the load wall) is the steal beam. (if that makes sense)