# your largest tank on wood joist floor?



## TNprogrammer (Jul 28, 2008)

I thought I'd do a quick poll. There is always a lot of talk about "what's the largest tank my floor will support?". So, I thought I'd ask you guys...what is the largest tank you have in your home that sits on a traditional wood joist floor? Also, a little other info would be helpful, such as where the tank is located(i.e., against an outer support wall, in the middle of the great room, etc.). Also, info about the joist would be helpful, such as are the joists solid 2x10s, manufactured pressboard material, open joist, etc., and how far apart your joists are. 
I'm well aware if the great article we have in the library about this subject, but I think it's always helpful to hear what's actually being done.
Thanks.


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## BioG (Oct 12, 2008)

You're much more likely to mash your floorboards then break joists. In many applications wood can support more than steel, after all, steel and iron are only as strong as their welds. If your home is built to code and well built then you could park your car in the living room if you like. Now getting it through the wall is a whole other poll


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## Jeffp (Jan 23, 2008)

i have a 150g on a wood floor ,2 yrs now, 2 foot crawl space, floor is oak , not sure of sub floor wood type ,pine maybe , tank is next to bearing wall , floor joists are 2x8 on 16 inch centers , supported the tank by placing treated 4x4's under sub floor at each end of the tank , under the 4x4's were 4-16000 lb.( the smallest they had) capacity floor jacks which i ordered from home depot , Under the floor jacks i placed 2x6 treated plank squares , i had first placed the tank empty , as this is what the builder of the tank advised , let the floor settle under the empty tank then put in your supports , right under where the ends of the tank/stand are , screw jacks just so they are snug, do not over tighten , when the tank is full the ends will be supported,,he stated all you want to do is transfer the weigth of tank/stand to the supports , this way the tank is not putting all that weight on the joist's, these guys have been building tanks for over thirty years , hope this wasnt to long winded .


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## GaFishMan1181 (Dec 17, 2008)

i live on a second floor apartment with wood flooring. house isnt built too well but i have a 55g, 46g, and 20g all in that one room. i am getting rid of the 46g because it is at a bad spot in the room. I wouldnt feel safe going bigger than a 75g in one spot at my house. oh and my 55g is in the corner with one side having my neighbors house and the other side is the front of my house. it seems very sturdy there.


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## Toby_H (Apr 15, 2005)

I kept a 6â€™ Diameter 300 Gal Rubbermaid Stock Tank in a spare bedroom of a rented house with a crawl space for about 8 monthsâ€¦ It was as â€œin the cornerâ€


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## TNprogrammer (Jul 28, 2008)

jeffp, are you saying that the 4x4s are directly against the subfloor, not the joist? If so,that is kind of interesting. Just like building a GIANT stand under the tank  Are you not worried about the ground under the wood planks settling/sinking? Just asking because the ground under my house seems kind of soft. Thanks for the input.


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## BioG (Oct 12, 2008)

If you have a 6 to 8 foot couch which weighs 200lbs. and you stuff 5 adults at 200 lbs. each on it (We did this many times in college!) you've got 1200 lbs. which is about what a 150 gallon weighs when full of water---can you see that couch, although mistreated and overloaded =, falling through the floor or even causing damage? I don't think so. Placing Jacks under a 150? Overkill I think. Although If I were selling tanks I would suggest doing it so as to keep my nose clean just in case.

Speaking of keeping my nose clean I found this on the net:

The guy asking was inquiring as to wether or not his China hutch and Dining table would be overweight for a 12x16 foot room with 2x10 floor joists:

"Doesn't sound like a problem. A structural 
standard for floor joists is 10 pounds per square 
foot dead load (means the house itself) and 40 
pounds per square foot of live load (means the 
stuff you put in the house, not necessarily living 
things). 
Almost any wood of the dimension you stated would 
meet or exceed that standard. Don't know the size 
of your center beam but I would suspect that if 
the joists meet the regular standard, the beam 
would also. A dining room table and a china 
cabinet are rather light loads, compared to other 
furniture, e.g., 800 pound piano, 500 pounds of 
books in a 3 shelf, 4 foot long bookcase. 
Realize that the live load of that room could be 
7700 pounds nearly 4 tons.

Don't worry. "

150 gallons = roughly 1200-1400 lbs. (Including stand etc.) even 500 gallons fits this guys quota (though I start doing the math when I get this close!). Assuming your home is built to code I would consider anything up to a 300 as dang near fool proof. Yeah I'm not afraid to say it. All things should be taken into consideration though seriously.

It's like I said "7700 lbs.".... Enough to parl your car in there! :lol:


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## BioG (Oct 12, 2008)

I would definitely put something under (foam flooring, mats etc.) to take weight of wood flooring or pergo so's not to mash it underneath anything over 50 gallons


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## Guest (Jul 25, 2009)

I had a 300gal.(96lx24wx30d) in my ranch for years. That's ~3500#. AND the way I had to sit it ran with the joist. The tank was only supported by 2-3 joist. I went under the house & reinforced the area where the tank would sit with 6- 8"x12"x1" concrete slabs with 4x4's on top of them wedged under the joist to add support. No problems, other than the creases it made in the carpet you can't even tell there was a tank there now that it's gone. My house was built in 1956 & I believe the joists are 2x8's. :thumb:


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## Maxima308 (Jun 6, 2009)

Make sure your homeowners /renters insurance would cover any accidents


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## 12 Volt Man (Sep 22, 2008)

http://www.cichlid-forum.com/articles/a ... weight.php

this article is not quite so easy going about putting huge tanks on normal wood floors..

when I was house hunting, I was planning a 6 foot 72x18x29.5" Aqueon 150g tank (that is really a 165 if you do the math) and I was specifically looking for a basement/ground level location so I would not have to reinforce the flooring.

obviously the tank is not going to fall through.

but 1800 pounds of weight in one relatively small area for 15+ years is a lot for a non reinforced floor to handle..right?

I didn't want to do any structural damage over time or have the floor sagging.

I did find a nice house with a spot for one in the end.. :

http://www.monsterfishkeepers.com/forum ... p?t=186451


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## Toby_H (Apr 15, 2005)

The concept of comparing 5 200 lb people sitting on a 200 lb couch to the weight of a 1200 lb tank has two major differences...

1. The tank will sit in one place for (potentially) many years without ever moving...

2. The people will be moving around and plopping into place. Weight in motion is increased many times over... To verify the difference gentle set a 12 lb bowling ball on one foot... then drop an identical ball on the other foot from 3 feet up  weight in motion...

Another detail to consider... leverage... the supporting wall is the fulcrumâ€¦ the floor joist acts as the leverâ€¦ weight applied in the middle of the room puts far more stress on the joist than weight applied near the wallâ€¦

Add those two theories together and Iâ€™d suspect that a 150 gal tank puts no more stress on the structure than a fat person dancing in the middle of the roomâ€¦


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## RyanR (Apr 29, 2008)

Toby_H said:


> I hung a weight off a fishing line and hung that on a nail right under where the tank was to be set upâ€¦ then filled the tank up with waterâ€¦ measuring the distance from the ground to the weight both before and after showed the floor did not â€œsettleâ€


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## 12 Volt Man (Sep 22, 2008)

Toby_H said:


> The concept of comparing 5 200 lb people sitting on a 200 lb couch to the weight of a 1200 lb tank has two major differences...
> 
> 1. The tank will sit in one place for (potentially) many years without ever moving...
> 
> ...


according to the article, the fact that say a 150g tank sits on one spot for years makes it much more of a problem not the opposite as you suggest:



> Another often unrecognized structural concept is that the duration of the load can be a factor in whether a wood structure collapses or not. Anyone that has ever used a chain saw to cut part way through a tree knows that. You can push on the tree and the tree does not break and fall down immediately unless you use a lot of force. Or you can use less force and sustain it for a longer period of time to make it fall down. A floor failure that I investigated occurred at 3:00 am on Monday morning due to an excessive load that was placed on a wood framed floor on the previous Friday afternoon. So if an entire professional football team crowds around to admire your large beautiful aquarium, it might not be any cause for concern unless they stand there all weekend.





> Myth #11: "My brother and I weigh 400 lbs together and we jumped off the sofa onto my floor and it didn't break, so I know that the floor can safely hold more than a 400 lb aquarium." Yes the dropped weight exerted a force greater than 400 pounds, but it was a short term impact load. If your 400 lb aquarium stays in the same spot for 10 years it might just cause the collapse that the jumping brothers didn't.


so, in the short term, yes it might be possible that a 150g tank exerts less stress on a floor than a fat person dancing. but not over the long term

which is how long we generally have aquariums..


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## frank1rizzo (Mar 14, 2005)

I had a 300 gal on a wood floor.

The joists were fine, but it messed the hardwood floor panels up a bit. You can feel that they are un-level now that the tank has been moved.


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## jfly (Feb 17, 2009)

i have a 150 tall loaded with 30 gallon sump.. and TONS of rocks.. it is a 4ft blueprint and could feel a little give (well at least i thought) .. so i cut some braces and bumped them under it


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## Chrispy (Apr 8, 2006)

Great topic,

I am actually in escrow on a home now. Just did the initial home inspection today and one of my main concerns was how my 100g tank would do with the sub-floor. The inspector say that two of the main internal walls (one of which is the one I wanted for the tank) are "fully supported." I am probably saying it wrong, but he explained it saying that the foundation wall is continuous under those two walls and the external walls. The joists were also 2x8 red-something that were 16" apart and ran perpendicular to where my tank would be. My 5ft tank should be able to span 3 joists.

Basically, he said that I should have no problems with the tank. I was at ease earlier, but now you guys have me scared again.

Edit: I didn't even think about my hardwood floors warping or such. Appreciate he heads up on that.


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## Toby_H (Apr 15, 2005)

12 Volt Man said:


> Toby_H said:
> 
> 
> > The concept of comparing 5 200 lb people sitting on a 200 lb couch to the weight of a 1200 lb tank has two major differences...
> ...


I apologize\ for not being clearâ€¦

As the article suggestedâ€¦ I agree that over time stress will build from a tank sitting in the same placeâ€¦

The two points I listed were simply reasons why comparing people on a couch and an aquarium were not a reasonable comparisonâ€¦ #1. Duration of an aquariumâ€™s stress is far greaterâ€¦ #2. Weight in motion is increased many timesâ€¦ Therefore I do not think we should consider people sitting on a couch in any way comparable to a tank in placeâ€¦

As for the Myth #11 quote aboveâ€¦ I disagree. Weight in motion increases drastically. So 400 lbs crashing onto the floor from 2â€™ off the ground is A LOTâ€¦ and in my opinion does prove something about the integrity of the floor in that place. Although, it is not a true â€œstress testâ€


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## billyh (May 24, 2009)

I have a 6 footer in a steel frame that rests on 4 fairly small footings in my office which is on the second floor. I have only had it about 3 months and no problems but must say the thought of it breaking through has crossed my mind more than once. Or a leak happening and i dont notice it or at night adn floods my flooy and the floor below. I certainly cant put joists in office below mine and just hope building which is maybe yen years old has strong wood flooring and the 4 legs distribute the weight enough. I did write a letter to my insurance company to see if i was covered but even coverage wouldnt relieve the grief.


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## Jeffp (Jan 23, 2008)

TN , I do go under the house on occasion and check the jacks , if they need adjustment it is very easy to do , after 2 years very little settling .


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## non_compliance (Dec 4, 2008)

I posted in another thread about having a 65 (3') and a 75 (4') side by side and only sitting on one joist. 75 is in the corner, and 65 is towards the middle of the room. Been like that for 2 months, although the 65 is temp and will be getting moved soon.


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## RyanR (Apr 29, 2008)

Yep. The "guys on a couch" or "fat guys dancing" analogies really don't compare to a big tank.

For big tanks on uncertain floors, I'd strongly recommend floor jacks when possible. They're stupid cheap, so there's no reason not to.

-Ryan


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## billyh (May 24, 2009)

what do you do if onsecond floor


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## TNprogrammer (Jul 28, 2008)

can you guys post a pick of one of these floor jacks?


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## RyanR (Apr 29, 2008)

TNprogrammer said:


> can you guys post a pick of one of these floor jacks?


Just go to Lowe's, HD, or your favorite home improv store. It's basically a pole with a screw adjustment.


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## JHammer489 (Jul 14, 2009)

I have a 75g, 46g, and 20g-all on the 2nd floor of my house. And I would fully trust the floor to withstand 125g+ in this house. So on a first floor, I wouldnt be scared to go as big as you want.


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## TNprogrammer (Jul 28, 2008)

Is this what you're referring to?

http://www.homedepot.com/webapp/wcs/sto ... =100022783


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## billyh (May 24, 2009)

I am not overly worried just that my 135 balances on 4 little posts so adds up to lots per square inch


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## brycerb (Dec 23, 2007)

I have a 225 with a 40 gallon sump in my livingroom with no addittional support. It is spanned across a few floor joists and against a load bearing wall. I also have a 35 gallon hex tank a few feet away from the 225 but also inline with the same wall. No problems. I think this thread is like the "how much rock can I put in my tank" one. Some people worry too much, *hakuna matata*!  :thumb:


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