Floor support

sammy77

Feeder Fish
MFK Member
Aug 1, 2009
76
0
0
midwest
I need some advice on how to support my floor for my 220gal(72"x24"x30"). First off the tank is going in my living room, which is on my first floor with a 8ft ceiling basement directly underneath it. Now, after taking numerous measurements I have some questions that I don't know answers to. The tank will sit 6inches away from an outside foundation wall, it will run parallel to the floor joists not across them which I prefer. I plan on "sister" joisting the joists that the tank sits on and also installing 4 of the steel adjustable foundation supports with 2x6's on top of them for underneath the floor. I would do this near the corners and also there is an existing wall of 2x4's in the center. Would this work? I've done plenty of home repair and such in the past but never really had to support a floor for this kind of weight. I appreciate your advice.

Thanks,
Sam
 

dxdx

Fire Eel
MFK Member
Jan 26, 2010
1,111
4
68
NJ, USA
I'm no engineer but I think you could get away with one or two posts. Four seems unnecessary, I've seen examples of people using only one for bigger tanks. Since you have a wall in the center underneath the tank, you could position one under each end of the tank. The home depot supports hold 18,000lbs which you're not coming close to.
 

skjl47

Goliath Tigerfish
MFK Member
May 16, 2011
4,397
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Tennessee
Hello; Your plan sounds good and should be strong enough. If possible after the joists are sistered a few braces between the joists can tie the joists together. This will not take much lumber or time. You may, as already mentioned, not have to put support poles under the end of the tank near the foundation wall especially if the new sistered board on that end extends over the foundation wall.
The 220 gallon can weigh from 2200 pounds to 2600 pounds.
I sistered some joists in my current home a while back. In addition to screws I put construction adhesive on the mating surfaces and clamped the new boards in place for 24 hours.
I have an old post saved with web addresses to some decent sites about floor strenght and will post them if you wish.
 

sammy77

Feeder Fish
MFK Member
Aug 1, 2009
76
0
0
midwest
I'm no engineer but I think you could get away with one or two posts. Four seems unnecessary, I've seen examples of people using only one for bigger tanks. Since you have a wall in the center underneath the tank, you could position one under each end of the tank. The home depot supports hold 18,000lbs which you're not coming close to.
Thank you. Those are exactly the ones I intended on using. I have seen a hundred post's on guys building their own stands, tanks, etc... Always it seems like the guys are placing the tank on a concrete slab. I guess no basements. Very few people post their work on floor support. lol
 

sammy77

Feeder Fish
MFK Member
Aug 1, 2009
76
0
0
midwest
Hello; Your plan sounds good and should be strong enough. If possible after the joists are sistered a few braces between the joists can tie the joists together. This will not take much lumber or time. You may, as already mentioned, not have to put support poles under the end of the tank near the foundation wall especially if the new sistered board on that end extends over the foundation wall.
The 220 gallon can weigh from 2200 pounds to 2600 pounds.
I sistered some joists in my current home a while back. In addition to screws I put construction adhesive on the mating surfaces and clamped the new boards in place for 24 hours.
I have an old post saved with web addresses to some decent sites about floor strenght and will post them if you wish.
Thank you. I'd love to see that post. Great idea on bracing the joists!
 

sammy77

Feeder Fish
MFK Member
Aug 1, 2009
76
0
0
midwest
Also, if I only go with 2 of the posts, where should they be? Directly under the ends of the tank? Or maybe a few inches from there? My initial plan was to center the tank in my living room, but unfortunately that won't work in the basement by 6inches or so...
 

skjl47

Goliath Tigerfish
MFK Member
May 16, 2011
4,397
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Tennessee
(OLD RECYCLEDPOST some words will run together, this happens when I copy and paste to the forum)) Here are some web addresses about floor capacity. The first address is a new one from a post by another Monster Fish forum member a while back. Here are the addresses again with the first being new to the list. Floor capacity depends on a lot of criteria, there is not a simple answer to the question.
This web address is added to the list http://www.cichlid-forum.com/articles/aquarium_weight.php It is perhaps the easiest to follow.
http://www.ehow.com/how_7485788_calculate-floor-load-capacity.html
The web address above is a site about calculating load capacities of floor joists. They use a formula for the strength of a beam: maximum load in pounds = FBd^2 / 9L.
The width of the wood joist in inches is B (1.5 inches for standard 2 by dimensional lumber.)
The depth in inches is d (7.25 in for a standard 2x8.)(9.25 in for a 2x10)
The distance (span) in feet is L (Unsupported distance)
F is something called the fiber stress when wood bends. It varies with the type of wood but graded lumber will be at least a 1,000 number, some are higher.
They use an example of 2x10 floor joists with a span of 14 feet on 16 inch centers and come up with 1,019 pd for each joist. They figure the area supported by each joist as 18.7 sq ft. They get 54.5 pd per square foot of floor area. I think this includes the weight of the flooring and anything else that is supported by the joists.
I looked at some other sites (Addresses listed below) and found a discussion of static loads and live loads. Two sites describe how to measure the deflection of flooring due to weight loads.
http://www.johnbridge.com/vbulletin/deflecto.pl

http://www.awc.org/calculators/span...d=10&submit=Calculate+Maximum+Horizontal+Span
I found these sites interesting but hard to pin down for a general rule of thumb. Too many variables involved; Type of wood, condition of wood, dimensional lumber or engineered truss, age of wood and on and on.
http://www.eng-tips.com/viewthread.cfm?qid=62845&page=10
 

sammy77

Feeder Fish
MFK Member
Aug 1, 2009
76
0
0
midwest
Thank you very much, that's about the best information someone can get on the subject. The good news is I've never heard of someone's tank goin thru a floor. lol
 

skjl47

Goliath Tigerfish
MFK Member
May 16, 2011
4,397
3,777
179
Tennessee
Thank you very much, that's about the best information someone can get on the subject. The good news is I've never heard of someone's tank goin thru a floor. lol
Hello; I have not personally known of that kind of failure. I suspect most structure failures are the sort where the structure sags, moves, pulls away, cracks or is in some way deformed. I recall a post or two along that line. Having done some home repair myself I find that sort of damage expensive to repair. It will surely cost more than the preventitive measures you plan. Good luck.
 

sammy77

Feeder Fish
MFK Member
Aug 1, 2009
76
0
0
midwest
Hello; I have not personally known of that kind of failure. I suspect most structure failures are the sort where the structure sags, moves, pulls away, cracks or is in some way deformed. I recall a post or two along that line. Having done some home repair myself I find that sort of damage expensive to repair. It will surely cost more than the preventitive measures you plan. Good luck.
I agree 100%. That is why I was thinking of using 4 posts versus the 2. The difference is only $100 or so. I know it's probably overkill, but I'm ok with that in these types of situations. Thank you again for all your help!
 
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