How much can a floor hold?

[RossW]

I am considering putting a 25g and a 32g into a home made "fish wall" on the second floor of my home.  The home made "fish wall" is 24"x48" and has two shelves for tanks, and two others for "stuff".

Does anyone know how much a "typical" house which is 8 years old can hold?

Ideally I would like tanks which are much larger than 25g and 32g in this wall.

I am wondering if a call to an engineer is just not worth it?

[MikeM]

The rule of thumb for water weight is 1 gal = 10 lbs.  Add some weight for rocks and so on.  If your tanks are perpendicular to your floor joists, or they will be up against a load-bearing wall you have nothing to worry about.  I'm presently considering either a 180g or 220g (6' long), and with a base with good contact on the floor (not feet, but a flat base), the load only works out to a couple of pounds per square inch, which any house should be more than able to support.

With the two tanks you have, I would seriously doubt you have anything to worry about; and with larger tanks, the key is to spread the load across as many structural members as you can.

With wall mounting, you are placing all the stress on the wall studs.  Again, as long as the wall is a load-bearing member, which usually run perpendicular to your floor joists and roof trusses, your weakest link will be whatever you use to fasten the tanks to the wall mounts.  I would think, and the experts can correct me if I'm wrong (I'm a computer engineer and the uni. statics course is in the cloudy part of my memory), that you would not want to mount more than a couple hundred pounds worth of tank to the wall.  Not that you asked about wall-mounting

[RossW]

The rule of thumb for water weight is 1 gal = 10 lbs.  Add some weight for rocks and so on.  If your tanks are perpendicular to your floor joists, or they will be up against a load-bearing wall you have nothing to worry about.  I'm presently considering either a 180g or 220g (6' long), and with a base with good contact on the floor (not feet, but a flat base), the load only works out to a couple of pounds per square inch, which any house should be more than able to support.

With the two tanks you have, I would seriously doubt you have anything to worry about; and with larger tanks, the key is to spread the load across as many structural members as you can.

My current version has four "legs" which are 3"x7" finished, two 2"x4"'s sandwiched.

With a little effort I think I could change it to have supports from leg to leg which would help to distribute the load a little further.

[audioslave_36]

have no fear about having your tanks on the second floor, I currently have a 135g, 75g, and 30g on my second floor, my house is still standing ,    as long as you distribute the weight your house will support your fish tanks with no problems.

[RossW]

So far it is looking good... now all I need is to find a good deal on some tanks which are max. 44"x24" and then I can replace my current 25 and 32g 

[darkdep]

NO worries whatsoever with that load.  Even with legs (although flat base is always better).

[Brine]

Just to add my two cents worth....people have water beds which are EXTREMELY heavy but because the weight is spread over a larger area there is no problem.
Its a matter of weight and area.

from the net..."when walking, a 100 lb woman in high heels exerts about 1500 psi, a 6,000 lb elephant in bare feet about 75 psi."

I would still rather have the woman in high heels at my place though....

[Saltcreep]

....., a 6,000 lb elephant in bare feet about 75 psi

When would an elephant not be barefoot?

[SuperT]

When would an elephant not be barefoot?

when it's wearing shoes 

[Chinaman]

when it's wearing shoes 

......and that means 2 rights and 2 lefts, all high heels.....

[april]

they are right.what the others said. .running the same way as your floorboards..which run opposite way of your joists. i had a few hundreds upstairs inan 80 year old building..hardwood floors..no problems. but against a wall.
think about it. sayyou had a   100 gallon. thats..1000 pounds spread out over 5 feet.
suppose...you had a party..and you had 5 guests over..that weighed 200 pounds each. you wanted to show them your new robert bateman picture on the wall. they all stood there..within 5 feet and oohed..and awed..over your picture. they wouldnt fall through...
best if you have more than 4 legs..or running boards..but if you have 2x4s..going down..and crossbeams..from 2x4s on their sides..and a bolt and a 2x4 under the shelf to rest on..it wont crash. the weight pushes straight down on each 2x4 . it will be fine.

[RossW]

I got in touch w/ the engineer who signed off on the plans for our house...

He informed me that:
- the current code is that the floor must be designed to hold 40 lbs/sq. ft.
- it is very unlikely that any builder would build beyond that due to costs, etc.

My current footprint of 2x4 translates to a possible load of 188 lbs/sq. ft.  This concerned him as it is almost 5 times more than the spec.

He suggested I put two jack posts under the floor to provide the required support.

I pointed out that my 8 year old daughter probably exceeds the spec. of 40lbs/sq. ft. and he mentioned that there is allowance for exceeding the spec. i.e.: fridge, etc.

I asked him what would be the worst that happened if I went ahead with my plans and he stated:
- the structure would NOT fail
- overtime it is likely the floor would sag, the hard wood would separate, the ceiling below would also sag, the walls on both floors would likely crack, etc.
- in general it would become a maintenance issue at some point

I have decided to go ahead with my plans and watch the stand, floor, walls, etc.

I can think of many situations, some already pointed out here, were this load is exceeded already on a regular basis.  Granted it is not a constant basis.

[april]

well..let us know..i cant believe they dont design houses to hold 300 gallon aquariums..upstairs. lol.
id get a stand that has more than 4 legs..or a sturdy solid base to spread the weight as much as possible.