Aquarium weight question

[txaggies07]

How safe would a 120g with a 40g sump be on the second floor of an apartment?

[YBeNormal]

You will get lots of opinions but no one here can really answer that question. It depends on where you are planning on placing the tank, how the weight is distributed, whether the floor joists in that are run parallel or perpendicular to the wall, width/thickness/spacing and age of the floor joists, other weight being supported by the floor joists, span of the joists, total weight of the aquarium and equipment, etc.

 

Someone posted a link last year to an article that explained all of the variables that must be considered when placing a larger tank on an above ground floor of a house or apartment. I don't remember who posted it or which forum it was posted in though.

 

 

Edit: Ah hah! Here is the thread I was thinking about and here is a direct link to the article that Tim (extreme_tooth_decay) linked to in the thread.

[Brian Ward]

Figure 10lbs/gal of water. That's about 1600 lbs in your case. Read the other article. I can show you the elementary statics math if you're interested but for the most part as long as the floor joists run perpendicular to the tank you should be fine. The load ends up being no more than a 200 or 300 lb person. All modern buildings will hold much more.

[Highland Reefer]

A lot of the Apartment buildings have concrete floors. If your apt has one then you don't have to worry at all. You really shouldn't have to worry about it, unless the building you are in is antique and not built to fairly modern codes, even then I have seen a lot worse out there and it stood up fine. One time I had a customer who had a 300 gallon system setting on a floor where all the joists had been eaten buy termites beneath it, half the subflooring was gone, the band boards were gone, the sill plate was gone. I scratched my head & wondered why it had not given way. We fixed it and it is still there, 15 years later.

 

[jason the filter freak]

Depends on the arcitecture, thats a lot of weight

[ErikS]

Do the math - compare the load of a 250lb person vs a tank............anyone guess which puts more load on the floor?

 

Yes, it's a lot of weight....................it's also spread out over a large area.

[zobey]

I am a structural engineer (PE, PhD) and I performed these computations myself before placing my 120g in my living room. Quite honestly, unless you are a trained engineer, I would trust nothing until I either had an engineer look at it or knew how to figure this out myself. Especially in an apartment where you don't own the building.

 

Its not a difficult as long as you know something about construction and how to determine loads and resistances of floor systems, but you need to know about the construction of the floor before anything.

 

I do agree with one statement I saw - the joists must run perpendicular to where the tank is to be placed - otherwise only a couple of joists will resist the weight of the tank! My tank is actually at an angle to the direction of the joists, but I made sure that enough of the joists were resisting the load of the tank!

 

Call me if you want me to evaluate - I do this type of consulting work all the time.

 

Rob Zobel

(703) 850-8831 cell

[Rascal]

How safe would a 120g with a 40g sump be on the second floor of an apartment?

 

It'll be perfectly safe as long as it remains on the second floor.

 

It's when it falls through and lands on the first floor that you'll have problems. :

 

Just kidding. Perpendicular to the joists and along a load bearing wall and you should be OK.

 

From what I've read when problems do occur it is usually sagging, not catastrophic failure, so be sure you check the tank's level when you set it up and then periodically every so often thereafter.

 

FWIW: I have a 150 running parallel to 2 joists above a crawl space. I supported the joists with 4 floor jacks on cinder blocks. It has held up fine after 18+ months but I am pretty sure the floor jacks are supporting some of the load. I have a remote sump so the total load on my floor is probably slightly less than you are talking about and with a slightly bigger footprint (5x2). Based on my experience, I would not put a tank that size parallel to the joists without being able to provide additional support.

 

One last thing to consider has to do with stand construction and placement. Assuming your floor joists are 16" apart and your tank is 48" long, the length and placement of your stand could make a big difference in how well your tank is supported. For example, if your stand distributes the weight across 48" and you put each end 1/2 way between two joists, your tank would be evenly supported by 3 joists. But if your stand distributes the weight across 50-52" and you placed it so that each end rested right on top of a joist, it would be fully supported by 4 joists.

 

[edit: my primitive diagrams didn't work, so you'll just have to picture it. )

 

If you've ever lifted a heavy object (like a tank) with three other guys and then had one of them let go, you have an idea of how much of a difference this can make.

Edited March 11, 2008 by Rascal

[txaggies07]

Thanks for the input. I am an engineer (Aerospace with a lot of structures in school), but don't have a feel for how much joists can hold. I can do the calculations, just need to know what the weight per joist would have to be. When I posted...I was hoping yall would just say...yeah...totally fine. I guess I will have to look into it more.

Edited March 11, 2008 by txaggies07

[SteveD]

You'll be fine as long as the above advice is followed in regards to placement, but don't sue me when it falls through . However, you might be violating a lease agreement if you're renting your apartment.

 

Thanks for the input. I am an engineer (Aerospace with a lot of structures in school), but don't have a feel for how much joists can hold. I can do the calculations, just need to know what the weight per joist would have to be. When I posted...I was hoping yall would just say...yeah...totally fine. I guess I will have to look into it more.

[Rascal]

Thanks for the input. I am an engineer (Aerospace with a lot of structures in school), but don't have a feel for how much joists can hold. I can do the calculations, just need to know what the weight per joist would have to be. When I posted...I was hoping yall would just say...yeah...totally fine. I guess I will have to look into it more.

 

 

O.K.

 

Yeah, . . . totally fine. Probably.

 

If you are looking for data and calculations, you can probably make more sense out of something like this than I ever could: http://www.fpl.fs.fed.us/documnts/fplrp/fplrp445.pdf

 

I started trying to figure it out once, got a headache, then gave up and just went to home depot and bought more floor jacks.