Floor strong enough?

[Joe M]

Hey guys. I just wanted to throw this out for discussion before i bought the 125 i found for a great deal on craigslist.

I live in an old, sturdy house. The support beams for my second floor are huge 12x6 or similar sized solid wood beams, hard as rock, about 18 inches apart. I have a 55 upstairs now, against an interior wall, parallel to the beams and only actually making contact with one beam with no issues.

My plan was to have a 125 with a 30 or so gallon sump against an exterior, load-bearing wall, perpendicular with the beams, making contact with 3 or 4 of them.

Now keeping in mind that im not expecting expert, water tight advice, what do you guys think? I think it will be fine for even double or triple that, and just wanted a few outside opinions. I wont sue you or anything, just want your thoughts. Thanks.

 

[Joe M]

C'mon! Nobody want to make me feel better, or worse, about this?

 

[GodofWar]

When i got my 150g I wanted it upstairs in my living room, but then i remembered how heavy it would be... so i did a little research and learned that even if I put the tank there and it held, over time the wood beams would slowly bend, and it would be very expensive to fix, so i decided to put my tank in the basement, and i dont think the cement will bend anytime soon lol

 

[Illbuyourcatfish]

I bought my 180 carried it upstairs filled it, and never ever thought about weight...

That was 8 months ago and not a single problem, upgrading to a 250...I might look into the weight haha.

 

[Joe M]

Yeah I'm not worried too much, especially with it being 6 inches from the main load-bearing wall in my house. I don't worry about the flexing of the beams either for the same reason. Thanks for the input guys. I guess i just wanted somebody else to say it would be ok too to reassure me a bit. Im confident it will hold now, and my uncle and dad have both been saying its fine too. I just gotta start building my stand now.

 

[bluehighways]

It should be fine. In a sturdy house, up close to a load bearing wall, AND running perpendicular to the floor joists you should have no problems at all, provided the tank sits on a nice solid stand with an adequate footprint.

The weight of water is around 8.33 pounds per gallon. So...

8.33 x 125g+30g(sump) = 1291 pounds of water. Add the tank weight and you should come in around 1400lbs gross.

Now, lets arbitrarily say your whole filled setup weighs in at 1500 pounds. Distribute this across 3 joists and you have a static load of 500lbs per joist, right up against a load bearing wall.

Across 4 joists the static load is only 375lbs per joist.

An even better way to estimate static load is to calculate per tank footprint in square feet. An average 125g has a base of 72" x 18". This is a footprint of 9 square feet.

1500lbs (to err on the side of caution) divided into 9 square feet is a static load of.....wait for it.........only 166.66 pounds per square foot.

This is not much of a working load for a well built house considering the gross weight is only 1500lbs, if you're obeying extra structural precautions like running perpendicular to floor joists, and staying within one foot of a load bearing wall you should have no problems. You cannot sue me if you do, however. Sorry.

Further, the actual load of the tank in practice will be distributed further out than just the supporting joists it sits on. The floorboards themselves will help spread the load to other structural members of the house, especially if you put a sheet of plywood under the perimeter of your tank stand. I would stay away from cement board, it is not flexible enough to accommodate any flexing or unevenness without cracking. Just use a piece of 3/4" plywood cut to slightly larger than the tank stand perimeter, cover it with one or two coats of Thompson's water seal and it will work just dandy. As long as it's not submerged or wet 24/7 it will hold up fine. It will handle the spills of water changes without any degradation. Be sure to coat the edges generously.

Good luck!

 

[12 Volt Man]

An even better way to estimate static load is to calculate per tank footprint in square feet. An average 125g has a base of 72" x 18". This is a footprint of 9 square feet.

1500lbs (to err on the side of caution) divided into 9 square feet is a static load of.....wait for it.........only 166.66 pounds per square foot.

careful here.

the tank weight of 1500 pounds is NOT distributed over the 9 square feet of surface area of the tank.

it is only distributed on the contact area of the tank stand to the floor only.

so the weight per square foot is significant.

if your stand has 4 legs for example, like many tube steel stands, the weight per cubic inch (or square foot but the figure for this will be small since the legs are typically 1"x1" or 1.5" by 1.5") is huge and will punch through most sub floors. my 150g for example, is on a tube stand with 4 legs such as this, but I am on a concrete slab ground level, so its a non issue. but it would be an issue in an upstairs living room, for example.

if your stand has a perimeter type stand like most LFS stands, with a 1" perimeter, the weight is again much more in terms of weight per cubic foot or per square inch.

not saying that the tank will necessarily be a problem, just pointing out flaws in the logic used for the math here.

we need to be careful with stuff like this because someone could make a similar mistake with a 300g tank for example and do real damage to their floor or house if the floor sagged causing the tank to stress a seam and leak.

 

[Joe M]

Oh yeah i realized this. The stand is going to be built by me and will maximize the contact between the stand and floor to better distribute the weight. I would never dream of using one of the steel stands on anything other than my concrete basement floor.

 

[CornBread]

I would fill it while empty and see how the floor settles, and then I would make my final decision I know plenty of people with 100 and 120 s upstairs but it does raise? In long term to me

 

[Joe M]

I would fill it while empty and see how the floor settles, and then I would make my final decision I know plenty of people with 100 and 120 s upstairs but it does raise? In long term to me

I'm sorry but I don't quite understand what you are saying. Could you clarify a bit for me?