How much weight can a floor handle?

[j0tca]

I agree on the two joists point. The strength of the floor is determined by the joists, if you're missing the joists, you're trying to put your tank on some plywood and air.

[zepfan]

"The fact is any 2X6 framed house will hold any tank, anywhere."

I believe he meant a tank that holds water, not an actual "tank."

As for the jumping test, you guys aren't factoring in the accerleration that all of your joints and your legs take. This counts for more than you might think. take a 200 lb steel block and drop it 3 ft, and you'll have yourself a test.

doug

[clkwrk]

j0tca - I do belive what I was told is right and the reason I used the width of my tank is because my tank is perpendicular to the joist if it was parallel to the joist I would have only got a total of 1300lbs . I visited the manufacture ( where my home was built and looked at the homes being built )and went over everything My floor as designed can hold the weight I listed no prob . My home is new and my tanks are doing just fine . Do some homework and you will find my formula is used all over for a very good idea of the weight a floor can handle. My floor can safely handle a 50 psf live load . I don't have time to prove anything to anyone so if you don't believe then don't .I did my research and taked to tons of people( not normal joes ) for months so I could sleep better at night and I was given the same answers and formula to go by for a very good estimate .

Although loads can vary depending on the age and condition of the floor and its joists. Also believe it or not most older homes are built better than these boxes are today. But thats beside the point .

http://www.cichlid-forum.com/article...ium_weight.php

And I also have steel beams that support my joists so please don't tell me what my floor can handle if you don't have the info.

Peace

[Lrgclasper]

I have a few comments about the discussion and please excuse bad grammer. I am in a rush so I can go skiing!

1. Generally code is for live loads at about 50 psf, while dead loads are less (20psf or less). My 250 gallon tank works out to be about 25 psf... a little above code but ok. Much more and I wouldn't feel confortable if people were jumping up and down. In fact I still discourage the practice. It is nice that building codes have "idiot" factors built into it that allows you to fudge a little.

I also don't think jumping up and down on the floor is going to give you an accurate reflection of load. Your floor may be too weak to take the load and fatigue, but because the load isn't constant, the stress is relieved and everything seems ok. A dead load would keep the stress on the wood until it failed. That maybe why dead load standards are lower than live load standards. You also have the elasticity of the wood to take into account. The rebound from the wood is actually generating force upwards. This can vary greatly depending on the type of wood and moisture content.

2. When I was figuring out tank weight per joist it helped me to put it into perspective. You think about the weight per individual joist and most tanks weight less than say a waterbed, piano, or heavy bookcase. A tank covers far more ground space than a piano leg. It shouldn't be an issue for tanks 125 gallons or smaller.

For heavier tanks it can be dangeours for some homes. Saltwaters weighs about 8.5 lbs per gallon. So, say you have a 250 gallon tank, then you are looking about 2500 lbs (including rock and stuff). If your 250 is 8 feet long x 2 feet wide, it converes 7 joists (6 full and a half of two). This amounts to about 350 lbs per joist dead load or 25 psf. Next to the wall shear stress should be minimal, so this isn't too much more than code. If you looked at the weight as live load... it would 4 times code... so this bears the question... how do you put the two together.. live and dead weight (i.e., the collapsed deck syndrom)?

Anyhow, I would not put anything more than 10% over code a non-load bearing wall. It should also be noted that the plywood will actually increase the floor strength and you can calculate for this.

Live

[ratimpulse]

Well i dont know but i know my new house where having special beams and things put in for my 300 gallon reef (parents dont no how much its really goign to cost them) And things.

[j0tca]

actually clkwrk,

I never told you what your floor could or could not handle. But, I'm sorry, you're wrong on your load safety estimates.

By the way guys, my recollection is code has a safety factor of 3-4 in my area. That means that the code is 1/3 of actual weight.

What I'm really saying, sorry to ruffle feathers, is that unless you saw the floor built, or talk to someone knowledgeable, who has seen your floor structure, you have no idea about what it can take. But, it is probably much higher than you think and not something to worry about. That being said, contractors know the strength of wood, and there is no one saying that whoever built (or "manufactured" lol) your house didn't take a shortcut.

In terms of the engineering, a 2x6 has a failure shear stress of over a 5000 ft/lbs

[Lrgclasper]

I totally agree with you J0tca. No feather ruffled here, enjoy the discussion. This is a topic that comes up a lot!

Your in Canada, you may have different building codes. Codes differ by region, type of construction, and a million other things you can think of (snow load, wind, building height, bla bla bla). Besides, if code is 1/3 your weight, then my live weight code estimate is fairly close. J0tca supported my point about "fudge factors", this isn't government work afterall. I do think putting a steel beam in your floor might be a bit excessive if your putting the tank next to a load bearing wall. It's another issue if the tank is going in the middle of a room, then (despite the 5000 lbs of sheer), sheer could be an issue depending on how far out in the room your are and the construction of your home.

I would just have an inspector take a quick look if your not sure. It may save you a bunch of pain and suffering.

[besl]

Ok, some specifics to my situation....
House is in Massachusetts, built in 1977. Floor joists are 2x8 (actual measure is around 1.75" x 7.25" approx) and are 16" on center. I wantt o put the tank on the end wall on a second floor so the 125 gal tank (72" x 18") would sit parallel to the joists. The way the joists ended up, although they are 16" OC, there is a joist 10" away from the wall I want to put the tank near - so depending on where the tank sits it will stradle 1 or 2 parallel joists.

Hope this detail helps with your inputs on this. I appreciate all that are responding - and even though I see some conflicting inputs, the general input seem sto be that I should not have any problem... further comments will continue to be appreciated!

[beerguy]

Originally posted by j0tca
Structural Engineer? I'm sure that's worth the $1000 assesment...

As an engineer I can say, don't listen to 99% of engineers. Get a carpenter if you really want to know. Cheaper and more knowledgeable.

Will

Apparently I should move to Canada and become a structural engineer. Perhaps that's $1000 up north, but it's not in the states.

Even if it was, if you're worried about it, it's chump change.

FWIW - I did not consult with an engineer for my 180. I did my homework and determined that it should be fine in it's location in my house. My point is that if it's going to keep you up nights worrying about whether your tank is going to fall through the floor it's worth the money.

[BeanAnimal]

Originally posted by zepfan
...As for the jumping test, you guys aren't factoring in the accerleration that all of your joints and your legs take. This counts for more than you might think. take a 200 lb steel block and drop it 3 ft, and you'll have yourself a test.

doug

Make that a steel block with 2 "feet" that resemble the area of human feet.... Lets see how many peoples floor sheathing can withstand that!


In any case, you will find that most of the "building codes" in the country are now (or moving towards by law) the BOCA internationalbuilding codes.

You will also find that most "local" code and licensing requirments have nothing to do with safety, structural engineering or practicality. They simply refelect local politcal objectives or "pork barrel" policies that help to favor a constituants or family members construction business. Most of the the licensing requirements for inspection and certification are tools to keep competition out of a local market. Local building codes are then pushed through to bolster the licensing and inspection head of the monster.

In most cases, spanning most eras of construction, your floor structure will easily and safely hold a large aquarium. As the tank size grows, so does it's footprint.

Most floor failures I have ever seen are the result of a house party. 100 people in a living room bouncing up and down. In every one of these cases, the floor joists cracked and sagged, they did not give way.

A friend owns a 100 year old tavern that feeds beer to 200-400 bouncing college kids at a time. The floor construction spanned 20 x 50 feet with no center beam. This was fine until we loaded the bar with 10 tons of sand for a beach party. We then had to add a center beam, as many of the 2x12 joists twisted ad began to crack. We have put the sand in the bar with thh 200-400 screaming college kids for at least 8 years straight. The floor is still there.

Another family member has a gun safe that is about 4x4 footprint and 7 feet tall. It weighs in at well over 800 pounds empty. This sits on 2x10 joist construction...in the same room that holds 20 adults during thanksgiving dinner witha 10 pound turkey to boot.

If you want to waste your money, then pay an inspector to walk around and look.

More important than the adding a beam is to ensure that the joists ties are secure, this will keep them from twisting and deforming under load.

Bean

[Lrgclasper]

I would think the 125 would be no problem, but just hire someone to come out and take a quick look. Reduces the worry factor.

As for the sand party... damn... half naked women running around? perfect

[j0tca]

besl,

I would be a little nervous about not having the stand on two joists. The joists are in no danger of sagging ro failing but the plywood floor underneath might sag with age. We wouldn't be concerned with failure here, only sag over time. Especially with the amount of water I tend to dump on my floor, I'de be much happier if I had the tank on two joists.

The joists are not going to fail guys, wood is simply stronger than that.

The 2X8 actual measurements are less because there is always a finishing loss on the wood. 2" is really 1 3/4", 3/4" is really 5/8", 1/2" is 3/8", it's always a standard loss on all finished wood. It's just easier to say 2X4, instead of 1 3/4"X 3 3/4".

And beerguy, exactley what are you implying that I shouldn't be worried about $1000, it's chump change? I would absolutley worry about spending $100 if it was unnecessary.

Will

[j0tca]

Apparently I should move to Canada and become a structural engineer. Perhaps that's $1000 up north, but it's not in the states.

Great display of ignorance there too bud.

[BeanAnimal]

Lrgclaser....

I think the point being made by some of us is that hiring somebody to aleviate your worry is a waste of money in this circumstance. To hire an engineer to do a discovery vist, and or blueprint interpretation, then stress calcuation is going to be rather expensive. The engineer will give you a real world estiamte of the weight your floor will safely hold.

If you hire an "inspector" he is simply going to measure the floor joist spacing and look up the loading data in a table. You can do this yourself at the library or on the internet.

It is a question of cost vs useable date or "opinion". If this were a much larger load resting on the same footprint, or deteriorated substructure, then I would be worried. Remember the subfloor is attached to the joists and does deflect some of the load outward to adjacent joists and vertical load bearing surfaces.

Bean

[Rivalpc]

Originally posted by j0tca
I'm an engineer who's been in construction for a few years.

I'de be happy to park a truck on almost any floor, anywhere in any house.

For a 65G tank, don't worry about a thing unless you think there is a problem anyway. If the floor is rotten, falling apart, and your neighbour stole your joists for a BBQ, worry about the weight, otherwise don't even think about it.

Will

I feel the same way about parking a truck or car on just about any floor in house (it will hold) because the weight distribution is wider, like that of a waterbed.

The reef tank thought would need to span across joist ends to hold it without any bracing. Putting it on a wall that has a single joist running length wise I would question doing. You would also need to take into consideration the sub floor material.

[scottfarcuz]

Everyone seems to want to debate weather the tank will come crashing through the floor or not. I am pretty sure it will hold the tank for many years, but I'm curious how much sag do you think the 72" long piece of glass is going to take?

Putting a tank that size lengthwise on 1 or even 2 joist WOULD keep me up at night.

[zatamzaf]

Stottfarcuz....

You hit the nail on the head...I would be worried about the creep in the floor joists

[orion76]

I live on the 17th floor of a condominium building.

I have a 400 gallon tank with a 50 gallon sump behind it and a 150 gallon fuge stacked on top of that and next to that I have a 250 gallon water storage tank and 50 gallon quarantine tank. Total volume = 900 gallons.

So far so good

This is really a "how long is a piece of string" question though, it's not an "is my aquarium too heavy" question, it's an "is my floor strong enough" question

[Versus]

Ok well here comes my crappy diagram .. Green is windows , Gray is the roof ( i have no rooms next to mine , garage is forward and under to the right ) Pink are walls below me .. Brown is just the outlay of the upstars hallway , the very bottom of my crappy diagram thats the balcony looking over to the downstairs.

All of the runners in the house go from top to bottom not across. As for the PINK line running with my wall on the right hand side of the room, it could be directly matching with my wall I am not 100% positive ( if i was i would put it against there ) ...

Like i said most of the upstairs just kind of "floats" with no support beams underneath etc.

The little area outside to the left of my room with the window is by the stairs , my current 55g is there. ( the 110 is downstairs )


just wonder on which wall and how it should be running , i dont know how you want to catch the boards if they should be running the length or width of the tank .. being by the window isnt a problem either .. my crabs eat hair alg faster than i can down ramen.


I dont need the MOST secure but with me moving back home I dont think my parents would enjoy 800 pounds sagging in above their dining room table and crystalware ..


( just adding this for a quick opinion , has any one used "firestorm" tools yet , i was going to get a new hatachi saw bench but these look sturdy and about 70 bucks cheaper )

[Versus]

and here is a kid getting decked by a cat

[scottfarcuz]

[Versus]

you have the balcony right the stairs are in the upper left , exactly the other direction .. anyways .. anywhere shown on there i can place it , does not HAVE to be in my room just close to it , so i can run out turn on the lights real quick and like BALAHOAHOIDHSA)HG)ASFAOIB BAOAHSHOIHS to the fish and scare em.

[Versus]

Originally posted by BeanAnimal
Make that a steel block with 2 "feet" that resemble the area of human feet.... Lets see how many peoples floor sheathing can withstand that!


In any case, you will find that most of the "building codes" in the country are now (or moving towards by law) the BOCA internationalbuilding codes.

You will also find that most "local" code and licensing requirments have nothing to do with safety, structural engineering or practicality. They simply refelect local politcal objectives or "pork barrel" policies that help to favor a constituants or family members construction business. Most of the the licensing requirements for inspection and certification are tools to keep competition out of a local market. Local building codes are then pushed through to bolster the licensing and inspection head of the monster.

In most cases, spanning most eras of construction, your floor structure will easily and safely hold a large aquarium. As the tank size grows, so does it's footprint.

Most floor failures I have ever seen are the result of a house party. 100 people in a living room bouncing up and down. In every one of these cases, the floor joists cracked and sagged, they did not give way.

A friend owns a 100 year old tavern that feeds beer to 200-400 bouncing college kids at a time. The floor construction spanned 20 x 50 feet with no center beam. This was fine until we loaded the bar with 10 tons of sand for a beach party. We then had to add a center beam, as many of the 2x12 joists twisted ad began to crack. We have put the sand in the bar with thh 200-400 screaming college kids for at least 8 years straight. The floor is still there.

Another family member has a gun safe that is about 4x4 footprint and 7 feet tall. It weighs in at well over 800 pounds empty. This sits on 2x10 joist construction...in the same room that holds 20 adults during thanksgiving dinner witha 10 pound turkey to boot.

If you want to waste your money, then pay an inspector to walk around and look.

More important than the adding a beam is to ensure that the joists ties are secure, this will keep them from twisting and deforming under load.

Bean

Problem is I cant add any support , all i have below me is the floor , and i cant use any support beams because there is no where to put them .. Good thing is i have about 100 pounds of livesand not 10 tons hehe.

[scottfarcuz]

At the arrow where I put "This is this the edge of the second floor?" There isn't a wall under that? If I understand the drawing there has to be one either directly under that edge running left to right or set a little ways up from the edge and the deck cantilevers over it...

[Versus]

where you thought the stairs were and it meets with the black line ( another room ) a big wall ( full 2 storys ) starts there and goes to the back untill it gets into the entry point of the master bedroom .. I will just take pictures later on today and go from there