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Safe load weight for a house floor


Moontanman

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I have been given a 225 gallon aquarium and I would like to set it up in my (rental) house. I figure it will weigh about 300 pounds per square foot with a 10 square foot base. Anyone care to speculate on how much weight a floor in a house with a crawl space, not a concrete slab, might hold?

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If your house is made of bearing walls and if you put your aquarium next to one of those of those bearing walls you should not have any problem.

However, an input in metrics would be great, I am not good in imperial units.

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Edit

 

If my conversions are correct,from your inputs in gallons and square feet that is about 800kgs/m2. That is way too much. please correct me.

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Since you have access under the floor you could easily ( :-( edit add obvious missing word) increase the local capacity under the aquarium with a prop or two in the crawl space.

 

A paving slab under the prop foot to spread the load on the ground would be useful.

 

Indoor fishing is the new sport

 

:)

Edited by studiot
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If your house is made of bearing walls and if you put your aquarium next to one of those of those bearing walls you should not have any problem.

However, an input in metrics would be great, I am not good in imperial units.

-------------

Edit

 

If my conversions are correct,from your inputs in gallons and square feet that is about 800kgs/m2. That is way too much. please correct me.

 

The footprint of the tank is about one square meter, so that would be 1360.7 Kilograms per square meter. 225 gallons = 851.7 liters...The weight of the tank and sand and the stand have to be figured in a well. I am trying to figure the cubic feet of sand it will take but I keep getting nonsensical numbers, to early in the morning and I can't find my calculator to check my figures but I am getting about 4 cubic feet which is about .113 cubic meters... I think.. I have been up all night writing, time to catch a nap, my figures may be off by an order of magnitude as sleepy as I am..

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The footprint of the tank is about one square meter, so that would be 1360.7 Kilograms per square meter. 225 gallons = 851.7 liters...The weight of the tank and sand and the stand have to be figured in a well. I am trying to figure the cubic feet of sand it will take but I keep getting nonsensical numbers, to early in the morning and I can't find my calculator to check my figures but I am getting about 4 cubic feet which is about .113 cubic meters... I think.. I have been up all night writing, time to catch a nap, my figures may be off by an order of magnitude as sleepy as I am..

You're in the US so bollocks on metric. :P

 

225 gallons*8lbs/gal=1,800lbs

4 cubic ft of sand @ 100lbs/ft^3 =400lbs

1,800+400=2,200lbs

2,200lbs / 10ft^2 =220lbs/ft^2

 

From the article I gave on calculating safe loading we'll use their example of 2x10 joists on 16inch centers with spans of 14ft. This gives safe loading of 54.5lbs/ft^2.

 

So your tank is about 4 times too heavy for that example. Studiot has the right idea of adding posts & pads under the spot where the tank will sit.

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I agree with Studiot and Acme, Moon. 2x4 braces on a broader plywood base, up against the joists will support that floor in a crawlspace. I did that under one level in my house where the flooring had some give to it.

This will be a case of "reprise de charge" (sorry cannot find the translation). It means you must "take the load" from a floor beam that is not strong enough.

To do that you must input a negative charge to the beam (a charge from down to up) prior to bringing your fish tank. It is not so evident because if you put not enough, the whole thing can crash, and if you put too much, the floor can be cracked and damaged.

 

Anyway the weight as indicated in the above posts is way too much. Here in Greece concrete floors are calculated for 250kgs/m2 of movable load.

 

So a good way to proceed is to bring your tank empty, put metallic adjustable scaffold elements beneath (taking care to spot the right emplacement) that you will put on wooden beams on the floor (what is the floor in the crawspace made up?), then fill the tank bit by bit and adjust the elements if needed.

Maybe ask for a professional, it can be dangerous if you are not used to do this kind of job.

http://i00.i.aliimg.com/img/pb/250/064/490/490064250_745.jpg

Edited by michel123456
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This will be a case of "reprise de charge" (sorry cannot find the translation). It means you must "take the load" from a floor beam that is not strong enough.

To do that you must input a negative charge to the beam (a charge from down to up) prior to bringing your fish tank. It is not so evident because if you put not enough, the whole thing can crash, and if you put too much, the floor can be cracked and damaged.

 

Anyway the weight as indicated in the above posts is way too much. Here in Greece concrete floors are calculated for 250kgs/m2 of movable load.

 

So a good way to proceed is to bring your tank empty, put metallic adjustable scaffold elements beneath (taking care to spot the right emplacement) that you will put on wooden beams on the floor (what is the floor in the crawspace made up?), then fill the tank bit by bit and adjust the elements if needed.

Maybe ask for a professional, it can be dangerous if you are not used to do this kind of job.

http://i00.i.aliimg.com/img/pb/250/064/490/490064250_745.jpg

First, Moontan is not in Greece. (First-and-a-half, we don't use metrics in the US.) Second, he doesn't have a concrete floor. Third, you don't specify which calculations are 'way too much' nor provide any calculations of your own. Fourth, taking all into account your input is poorly supported.

 

Moontan, if you will give us the exact dimensions of the tank footprint, the joist size and spacing, and the location of the tank relative to outside walls and existing posts & piers, we can calculate where you need to add additional support. Contrary to what Michael implies, these supports should not spring the floor upwards, but only hold it level. Once the tank is full, some settling might occur which you can check for with a level and if there is any sag you need only drive shims between the posts and joists. Rather than the 2x4 posts recommended by Phi I would use 4x4s, not because they are stronger but because they are less likely to slip out of place from vibrations. Depending on the clearance you may want to put the posts under a beam that spans multiple joists rather than putting the posts directly under the joists. (See image below of typical post & pier construction. Note the metal straps that keep the posts from slipping out from under the beams.) As to professionalism, I had a 15 year career as a carpenter and cabinetmaker and know something whereof I speak. :)

 

pier-post.jpg

Do you understand folding wedges?

 

These are one of the greatest engineering inventions of all time.

Yes exactly. This would be the form of shimming I just mentioned. Since these folding wedge shims would be used when adding the post at first, then should any consequent settling occur after the load is applied it can be corrected by driving the shims in further.

 

Bundle o' shims:

0SHIMS.jpg

Edited by Acme
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First, Moontan is not in Greece. (First-and-a-half, we don't use metrics in the US.) Second, he doesn't have a concrete floor. Third, you don't specify which calculations are 'way too much' nor provide any calculations of your own. Fourth, taking all into account your input is poorly supported.

 

(...) As to professionalism, I had a 15 year career as a carpenter and cabinetmaker and know something whereof I speak. :)

Well, the entire rest of the world use metrics.

 

Concrete is stronger than wood, I just gave an example of acceptable loads. In metrics.

And when I spoke of professional, I ment someone to go there and look at the exact situation, not anyone giving advices over the Net.

 

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(edit)

Loads of 1 ton/m2 are sometimes used in industry buildings for heavy machines. Not in houses.

Edited by michel123456
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Well, the entire rest of the world use metrics.

So what? Moontan is in North Carolina USA.

 

Concrete is stronger than wood, I just gave an example of acceptable loads. In metrics.

And when I spoke of professional, I ment someone to go there and look at the exact situation, not anyone giving advices over the Net.

Moontan is there and can give us the exact situation from which we can calculate an exact solution in the standard measures he is accustomed to. :)
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Since these folding wedge shims would be used when adding the post at first, then should any consequent settling occur after the load is applied it can be corrected by driving the shims in further.

"driving"? You mean: you are currently advicing a novice to hit with a hammer the shims with a ton or more of water above his head. A carpenter like you can do that, not everyone.
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"driving"? You mean: you are currently advicing a novice to hit with a hammer the shims with a ton or more of water above his head. A carpenter like you can do that, not everyone.

Moontan is not a novice to hammering. If he's comfortable adding the posts in the first place -which requires hammering in shims- I see no problem hammering the shims later. Moreover, what do you suppose is the weight of the existing house above his head when he's under the house? :rolleyes:

 

Moontan, if you're not comfortable doing any of this work yourself, hire a licensed contractor. For a further declaration of liability release, check with your landlord before doing any of this work. :)

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Right now I am flooded by extreme rainfall, my house is sitting in the middle of a pond at this moment and the crawl space is flooded as well, the last week we have measured rain in feet per day not inches. I will get under the house and take some measurements as soon as things dry out a little.

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Right now I am flooded by extreme rainfall, my house is sitting in the middle of a pond at this moment and the crawl space is flooded as well, the last week we have measured rain in feet per day not inches. I will get under the house and take some measurements as soon as things dry out a little.

But flooding is the most fun time to be in a crawl space! And because wood is buoyant, the floor is less likely to fall on you. :o

Acme if you have any photos of the additional strengthening joists that are put in the loft area under where the water header tanks will be situated, they could be a helpful example.

I don't recall ever doing any special framing under hot water tanks so I'm not clear on what you mean. Since I don't know of any photos, maybe you could dash out a little drawering to clarify. Sometimes we did sister joists and/or double up headers under bath tubs but that was usually to get back the strength the plumbers lost when they put in their drain lines through the joists. Admittedly, sometimes in remodels, I was that plumber. Can't see it from my house. :rolleyes:
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Right now I am flooded by extreme rainfall, my house is sitting in the middle of a pond at this moment and the crawl space is flooded as well, the last week we have measured rain in feet per day not inches. I will get under the house and take some measurements as soon as things dry out a little.

 

Oooh, change of plans! Put a liner in the crawlspace and install a glass floor. Et voila!

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I am considering setting it up on my carport, (concrete slab floor) since I am planning on imitating a local biotope (boiling springs) all the animals and plants in it will be able to live in the mild winter conditions here. If I decide to go marine it will be with local sharks and rays so the same will be true.

 

I'm still brainstorming, it will probably be next spring before i finish repairing it.

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