Do I Need Floor Supporting?!?

One of the questions that is inevitably asked in every aquarium chat room, newsgroup and bulletin board is "just how large an aquarium can my...
  1. fab

    fab Well-Known Member R2R Supporter

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    I think you are close enough to have a professional check the calculations for you. If you are near a university with an architecture or an engineering department you might be able to get a professor or a PhD candidate to help you. Or just walk into a construction engineering company and ask for help. You might luck out. If they will not help ask for some references to someone who can help.
     
  2. reef123456

    reef123456 Active Member

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    if I want to put up my 800 gallon on the stand in garage, it wont be a problem right? cuz the garage floor is concrete
     
  3. Glasswalker

    Glasswalker Well-Known Member

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    Hey, I am putting my new tank into the room (currently in garage) shortly. And figured now would be a good time to quickly ask here to confirm (I've done some figuring and think I should be good in general). Anyway...

    Here is build thread with particulars on tank and stand:
    https://www.reef2reef.com/threads/first-build-some-questions-and-documenting-my-build.241255/

    The tank is 48" long 65gal, with 20gal long sump. Stand is 55" long wood stand, very over-built. should distribute weight nicely along the floor.

    Things contributing to weight:
    Display is 65gal 10mm glass, I'd guess it weighs 80lb, will have 50lb dry rock, and about 5-10lb live rock. And I have purchased 80lb of sand, but not sure how much I'll need to use.
    Sump is 20gal long, probably weighs about 25lb to 30lb will only be filled to 9" deep, which is about 15gal, will have a little sand in the fuge chamber (prob 10-15 lb) and some rubble (maybe 5-10lb).
    Pump/skimmer/plumbing probably total another 25lb give or take.
    I'd account for a couple more gallon of water in the plumbing when operating
    Stand weighs about 150lb, maybe a little more.

    The Room:
    First off, this is a house, not an apartment building. I'm placing the tank on the ground floor (with basement underneath it).
    The room is my dining room. It's got very minimal furniture (small dining table, and 4 chairs, all of which are light).
    Room has usually only my wife and I. I'm a big guy so lets say 500lb worth of people usual load. That may go up to at most 1000lb of people if we have guests and such.
    The room is about 14' long by 10' wide. There is a steel I beam running across the room at about 4' from one wall, leaving a 10' square floor space with joists carrying the weight. (the other 4' x 10' section is seperate joists). The I beam is supported with steel Jack posts on one end of the dining room and concrete foundation on the other end.
    The "back wall" (opposite the open end of the room where the I beam runs) is a solid, reinforced, poured concrete foundation wall.
    The basement under the room is our laundry room, and is unfinished, so I can see the joists/structure clearly.
    The joists run from that foundation wall, to the I beam.
    Joists are 2x10, on 16" centers, running 10 feet. They are cross braced with X bracing twice across that length.
    There are a couple small drills for electrical, but those are closer to the I beam end.
    The tank will be going against the short wall right up against the concrete foundation wall. with the 55" stand running perpendicular to the joist direction.

    My assumptions/conclusions:
    So based on building code (40lb/sq foot) the 10' square segment of the room should handle 4000lb of live load evenly distributed.
    The section of joists where the stand load is focused is 55" x 10' which is about 45 square feet. Should handle 1800lb evenly distributed.
    Total weight of the entire system supported by the stand (including the stand itself) should be approx 1200lb
    Weight will be focused right against a solid concrete reinforced foundation wall, and load is only 20" out from the wall at most (stand is 20" front to back). Meaning that the vast majority of the weight is being carried by the foundation wall, with the main concern being shearing failure of the 2x10 joists.
    In addition, based on observed structure, the flooring in that room should be able to take a safe live load much higher than the building code. (AWC tables show that with 16" centers standard grade 2 or better 2x10 joists on a 10' span, will support a 100lb/sq foot live load with safety margin in standard home building conditions, with shearing strength of 150lb/sq inch for the bearing ends. If we assume at least 3" - 4" over that concrete wall, and the same over the I beam, shearing strength per-joist should be approx 900lb per joist. So if I can span 3 joists that's 2700lb shearing strength, and 4 joists that's 3600lb.

    Anyway long story short, I think I'm perfectly fine, assuming there are no major defects/issues in that wood (such as rot/pests, and so on). Which it appears good in that regard based on visual inspection.

    So even if I manage to get 1000lb of people crowded closely around the tank, that's a focused load of say 2500lb on the peak on that section of floor, which should still be well within the safe loading limits of the observed structure.

    All that said, I'm no structural engineer, so I'd love to hear a more informed opinion on the above ;)

    Thanks!
     
  4. acer

    acer Well-Known Member PMAS Member

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    With that size tank you should have no issues - unless whomever build the house did it very badly and cut corners that you cant see by visual inspection. I went to my State Farm agent ( to get my discount double check- no , just kidding) to see if I need to get a structural engineer report in order to make sure that my insurance will pay for stuff if the floor does give or sag causing the tank to crack dumping 150 gallon of salt water all over. He said based on my house construction ( see above) - and the weight of a 150 gallon tank ( 2500 pounds over a 24 x 60 area) and where it is being placed , no report is necessary and the tank and the house and all my personal possessions are still fully insured. I did call a few local places and never got a call back. So, that is good enough for me.
     
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  5. fab

    fab Well-Known Member R2R Supporter

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    Only if it is reinforced concrete; i.e. , has "rebar" embedded in it. It should be reinforced if the garage was built within the past 40 years.
     
  6. acer

    acer Well-Known Member PMAS Member

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    wow- 800 gallons !!! That's a swimming pool, not an aquarium.
     
  7. rioreef

    rioreef Member

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    Unless your aquarium is sitting on the floor directly, your stand is the first support to worry about. Staying with wood construction, even if you reinforce it studs, I bet your floor joists are still stronger.

    That said, orientation of the joists is important. I have always put along a wall with joists that are perpendicular to it. Also in my current setup, the tank is in a large room (20x15). To stop any floor flexing because of activity in the room (kids playing) I have put a wall up below the floor supporting the aquarium that sits about one foot out farther that the front of the tank. This helps a lot to isolate and greatly increase support for the tank. You could even sister up the joists to help the floor strength too.
     
  8. nolaron

    nolaron Well-Known Member

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    Exactly what I needed as I'm planning my 120 upgrade. Thank you!!
     
  9. fishview

    fishview Well-Known Member

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    I have a 300 gallon ( 96" x 30") with 80 gallon sump on the first floor. The tank is 15" from the steal I-beam. It has no problem so far (3 years).
     
  10. Scotch57

    Scotch57 Member

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    265 gallon over 2000lbs doubled floor joists and cross support no problem
     
  11. s2nhle

    s2nhle Well-Known Member

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    Wow, great to know. Thank you very much.
     
  12. STEVENGBRYAN

    STEVENGBRYAN New Member

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    My house was built in 53, before I installed my 300 gallon tank I called local lumber yard and had their LVL sells person do calculations on floor and bought LVL's to install for support.
     
  13. Scotch57

    Scotch57 Member

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    Had a 260 glass tank on second floor doubled up the floor joist under tank when to menards bought4 floor jacks
    Tapco Adjustable Floor Jack - 4' 8" to 8' 4" $33
     
  14. kalare

    kalare Well-Known Member

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    There are structural engineering firms everywhere, you could even check craigslist for guys working out of their garage...the check shouldn't cost you more than like $150-$200 (at least here in CA-cheaper elsewhere).

    Not to disagree with you, but I'm a practicing structural engineer, and I would not trust either a PhD candidate or construction company. PhD candidates will want to over analyze everything and will most likely want more than is necessary and construction companies will give you the old "it's worked and I've done this for XX years and should be fine" talk. I've had extensive experience with both examples and it's never the best option for the client. I can't tell you how many times I've reviewed something that a framer or contractor has put up that is not to code and even in some cases unsafe.

    If any of you guys still have questions about your floor systems, I can try and help you out. Dimensions of rooms, supporting members underneath your floor, joist sizes and span direction, tank size and footprint, and location in room will help, as will photos of the framing. In most cases tanks are fine, but it's always a good idea to double check.
     
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  15. s2nhle

    s2nhle Well-Known Member

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    Hooray, we have expert in the house.
     
  16. ReefTalk

    ReefTalk Well-Known Member

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    If you have no crawl space and no basement , you should be fine to have just about at big as you want fish tank in your house .
     
  17. Scarybo

    Scarybo Well-Known Member Partner Member

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    Kalare,

    What's your opinion on my situation. I live in an apartment built in 2003. Its a large complex. I'm looking at setting up a small tank. Red Sea Reefer 250. 54 gal DT and 11 gal sump. I would be setting it up against a main wall. My lease/landlord is cool with the tank. I'm just cautious. Should I hire a structural engineer. Everyone has told me I should have no issues but I like to check all boxes. Thanks
     
  18. ReefTalk

    ReefTalk Well-Known Member

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    It seams to me you should be fine , your tank would weigh about 570 pounds, those beams are meant to hold that much weight , but if your still worried I would contact the structural engineer .
     
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  19. kalare

    kalare Well-Known Member

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    So long as the tank is against a wall, should be OK. Is your room a square, or rectangle? In general, you'll want your tank against the LONG wall, as the floor joists will most likely be oriented so they span the shorter distance. If you're in an apartment, you'll have tenants below you and a structural engineer will not be able to give you a definitive answer without punching a hole in your downstairs neighbors ceiling = not happy neighbors. I wouldn't personally worry about it at all, and since your land lord is OK with it, all the better. 60 something gallons isn't a big deal, just imagine having three football players standing in one area of your room! Floor shouldn't fail :)
     
  20. Scarybo

    Scarybo Well-Known Member Partner Member

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    I'm thinking it should be good. Looked under the carpet against a wall and it was concrete under the pad.
     

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