Tank on 3rd floor condo

[Mr31415]

Just remember that whatever the weight the floor was designed to carry - it is assumed it is being spread evenly across the whole floor. A tank is a huge weight on a very small footprint, which increases the pressure dramatically.

In South Africa a second level floor is almost always a 20-30cm thick cement slab. This slab is designed to hold anywhere between 150kg/m^2 to 300kg/m^2. Obviously the safety margin is something huge like 3-4 times that, however you never want to go in to that margin as it depends on the building contractor exactly how much that margin is. You will never know for sure.

So if I were to put a 500l (approx 135g) tank on that floor, the tank will have an approximate weight of 666kg/m^2 (assuming stand etc. weighs 150kg). That is already outside the spec.

I did however find if you place your tank against a load bearing wall you can make this work... But it is only exact science if you can get the info from the contractor who build your floor.

 

[madmike]

I have requested the blueprints from the builder in my offer to purchase so hopefully I will be able to get a professional opinion once I have them in hand.

I was planning on placing my pool table in the loft as it is a pretty large room, but i think that all of this weight just might come crashing down on me,lol.

 

[kingnai]

the 2000 lb is per square inch... it will hold no problem

 

[specialkb]

^^^ yeah should be no problem at all.

 

[Mr31415]

kingnai - are you sure? It sounds excessive - 900kg per square inch.... My 22cm thick concrete floor is spec-ed at 300kg / sq. meter...

 

[clsanchez77]

If the building was constructed recently, a good approximate rule of thumb for the floor design should have been 100 pounds per square foot, typical for multi-family, unless the area is designated as a bedroom or sleeping area, then it could be less. However the reduced loading are generally not allowed in apartment buidlings. And then the design is deflection controlled, not stress controlled, so you can exceed it but it needs to be evaluated. There is no way to know withou finding the plans and/or the designer.

Another way to look at it is a full size sofa with three people could be upward of 900 pounds.

Finding out who the designer was is a good start, if you can. Also, you have a structural engineer assessment should not be that much $250-$450. You do not need the entire buidling evaluated, just the loft. We spend several $,$$$ on the tanks so why not.

I suspect you are good for anything normally stocked sized.

I just estimated my 90g as 1300 pounds (250 for the setup, 770 in water and 300 in rock and sand) and covers 6 square feet so I am looking at 217 psf.

While a 300 gallon tank would be about 4,000 it would cover 18 square feet so would only increase to 222 psf.

And by the way, my tank is on a second floor condo, constructed 35 years ago and the second floor is 2x10 pine joists at 16" spacing. I suspect your floor will be sturdier.

Chris

 

[RGibson]

Be sure you get the as built blueprints.

 

[beez]

Hi all!!!

FWIW, this is an informative article about large aquariums on wood framed floors thats been reprinted on a lot of fish sites...as clsanchez77 said, its not a simple calculation..you'll need to do a little research:

http://badmanstropicalfish.com/articles/article28.html

As far as a concrete subfloor, the 2000 lb. refers to the average per square foot weight limit, I believe. There's no way the 2000 lb. is the total weight your floor can support...there isn't a condo on earth that doesn't have far more weight than that sitting on it, once you figure in all your appliances/furniture, people, etc.

Good luck:thumbsup:

 

[clsanchez77]

As far as a concrete subfloor, the 2000 lb. refers to the average per square foot weight limit, I believe. There's no way the 2000 lb. is the total weight your floor can support

Actually that does not make since to me either, maybe for an elevated garage floor or similar, I don't know. For typical building design, you are looking at live load numbers between 20 pounds and 150 pounds per square foot. Total weight is just a useless number as wheather is stacked (point load) or spread (uniform load) makes a huge difference in capacity.

Also, I believe that reference was to a gypsum material whcih is not used for flooring around here, it is water soluble! So I do not what that statement intent was.

Also again, everyone is overlooking the weight spread of the aquarium. A typical 180 gallon system (6'x2'x2') is easier to support that spreads over 12 square feet than a custom 180 gallon tall system (6'x1.5'x3') that spreads over 9 square feet. The tall system increases the floor load unit by about 30%.

Chris

 

[Frankysreef]

100 lbs per sq foot doesnt make sense does it?
Most large men, when they walk around easily are going over that standard. Over time most men and women will fall through the floor.

In the middle of the floor it is 80 lbs per sq INCH.

Near a load bearing wall those supports can hold 10000 lbs per sq inch.

Most tanks weight are spread out over the floor, a 24 inch tall tank will usually work.

But for safetys sake I would put it against a load bearing wall.

I went an extra step with mine and lag screwed using 5/16 inch lag screws and 2 2x12s bolted my frame to the wall.

The shearing force of each screw is about 10000 lbs.

good luck

 

[clsanchez77]

100 lbs per sq foot doesnt make sense does it?

That is structural design for you That is why I stick with water. Actually from what I remember from structural design, some typical loading values are:

Libraries 120 psf
Apartments, Office Buildings 100 psf
Residential Sleeping Areas 50 psf
Attics 20 psf

While you are correct an average person is 180 pounds, you typically will not fill a room with as many people that physically fit. Additionally, wtructural design is normally governed by deflection limits, not strength limits, which means you have added capacity. And then on top of that, you use load combinations which each have a different set of safety factors.

Most tanks weight are spread out over the floor, a 24 inch tall tank will usually work.

That is my point as well

The lag bolts are unnecessary IMO, tanks are too heavy to tip over and I am not sure that the lag bolts really help unless you built your stand specifically built for it. If anything, if the floor were to settle and you supported the back of the stand with the lag bolts, you could make your tank unlevel as the front would settle with the floor and the back would be restrained. But then I guess it could work as the wall should settle too.

I really just think everyone is over analyzing this. They usually do when it comes up about once every 6 months.

Chris

 

[engine]

75 gallon tank w/ 30 gallon sump in my 2nd floor apt........got it in writing from the office that I could have the tank and got renters insurance too just to be safe. Also, my apt is waterbed safe for upstairs and when I pulled up the carpet to look under the padding, the subfloor appeared to be similar to concrete....but it seemed a little too brittle (it was easy to chip) to be standard concrete. Anybody know what it could be?

 

[clsanchez77]

Sounds like you have what I have. It is a lightweight concrete slab. You construct with conventional wood frame decking and sheathing, and then pour a thin light wiegth concrete deck. All the concrete does is provide stiffness and some thermal and sound insulation to the floor. It is not intended to provide any significant structural value, however does help in spreading heavy loads (water beds & aquariums) to nearby beams. Also, if you spill water, it wont go straight thru; but if you spill a lot of water, it will just go around the concrete slab at the nearest load bearing wall.

Chris

 

[MusMusculus]

This helped me: http://badmanstropicalfish.com/articles/article28.html

 

[clsanchez77]

<a href=showthread.php?s=&postid=9783623#post9783623 target=_blank>Originally posted</a> by MusMusculus
This helped me: http://badmanstropicalfish.com/articles/article28.html

Excellent Link

 

[wsoldier]

[MENTION=19961]madmike[/MENTION]: What did you end up going with? I know each situation is different but I'm curious what you decided on. Thanks.

 

[Kevin Guthrie]

Btw regarding the 2000 lbs number, it is the psi that the subfloor can take without crumbling. This lets you know that high heels probably will not wreck the floor's surface. It has nothing to do with how much weight the floor's structure can hold.

http://www.maxxon.com/gyp-crete/data

The main reason to use this as a subfloor is noise deadening.

 

[shaginwagon13]

I am purchasing a 3rd story condo with a loft above it. I want to put a large tank in the loft but i dont know what size tank the loft will support. The condo was built this year and is brand new. Any info on where to begin would be great.
Thanks

Is the condo floor joists cast concrete, wood or steel?

That will make a massive difference.

 

[WVfishguy]

Do what i did get the blueprints and find out where the load bearing wall is and ask a professional if the wall could support the weight of the tank (Gallons * 8 = lbs not including tank). If it's a wood beam and it starts to sag it could be a very exensive repair.

ps. in my case it is a cement floor and a metal beam so everything is fine.

I did this if the client wanted a large tank. I had a doctor who wanted a 200 gal. salt tank on the second floor of a new building.

Thank goodness the contractor was readily available. I called him and told him approximately what it would weigh, and I think he pooped himself.

I ended up setting up a 75. :lol:

 

[Johnseye]

You need and want a structural engineer to look at your house and tell you in writing. Just by asking the question you know the risk and possible outcome. Stand, tank, rocks, sand, water, etc. Factor it all in.