I would post more pictures but can't. I have 2x8 under the feet as I thought it may spread the weight a bit more. The tank is sitting on two outside walls but running with the joists. The basement has a wall already there. Then I made another wall about 4-5" in from there and sat my stringers (hope that's the right term) on the wall then have the 2x8 doubled up sitting on the jack posts. I'm not that fussed about using this space so if its better to build a new wall and remove the posts I still can?? Thanks.

His photos are small. But it looks like a ~10" piece of 2x6 under the feet of the posts, well at least the one that I can see.

The wood will hardly compress. I seriously doubt it will split. His biggest issue with the wood is that it is not pressure treated and directly on the concrete.

The part you are unclear of is I am saying the wood he has will be as effective as the small thin piece of steel that you are recommending.


He is putting a tiny load on this part of his floor, he's not putting a 40 ton Leopard Tank in his living room.

How far is the span of your joists in this area?


flicker is an easy way to upload more photos.

Joist span is about 10' to the iron bar that's in the middle of the house.

2x10 joists? Looks like it's an older house, are they hardwood joists too? Or standard lumber.

So 10 feet from foundation to main load support?

You have nothing to worry about. Build extra support under the tank if you wish. But it's not going anywhere.

I might build a simple wall in the center of where the tank is, but it would simply be to take a bit of the bounce out of the floor for the fish tank. But I probably wouldn't do it until after I had the tank there and full to see if it's even an issue that needs to be addressed.

I am simply stating what I would do. I may not be an engineer. But I deal with all forms of construction trades every day, and for significant loads.

Just think about how much weight your living room is holding when you have a little party, and that's a live load which is significantly more force than the realistically static load of your fish tank. And the guest are normally in the middle of rooms, not hugging the load bearing walls.

Thanks. 2x10 old house from the 70's solid wood. Yes 10' from wall to main load support beam. So ill basically leave it as is then?? I'm happy with it I think and I shouldn't have any bounce with it like it is. Thanks :biggrin:

Ya it's not going anywhere. A 10' span is nothing, and your concrete has had a long time to get hard, it's not going anywhere either.

What you have is way overkill. The house itself would hold the weight just fine.

What material is the finished floor under the tank? As long as it's not tile, it's ok if the floor flexes a bit. It is also important to note that if the floor flexes too much and the stand also flexes too much the tank could break long before the floor would fail. Make sure the stand is well designed too. Personally, I would keep the jack posts simply because the tank is running parallel to the joists. if you do decide to remove the jack posts, at least add blocking between the joists under the tank and a couple joists beyond the edges of the tank to help with deflection.

Here's a great article written by a structural engineer (since 1976). Residential Wood Framed Floors and Aquarium Weights

His Conclusion: "Aquariums up to 55 gallons can be placed almost anywhere without much worry at all. Many tanks larger than 55 gallons and no more than 125 gallons will be okay, if they are placed in a good structural location and your floor framing is free from significant defects. For example, a 125 gallon tank, on a wooden stand, placed perpendicular to the joists up against a bearing wall, will often be okay without any additional structural support. If your tank is over 125 gallons, then it is likely that you should consider adding supports under your wood framed floor. Please realize that these are generalities that may or may not apply to your particular situation."

This is wood blocking that really shows no signs of compression after 3 years holding 45,000 gallons of diesel fuel.

http://farm8.staticflickr.com/7389/9...6e0b9df8_c.jpg
The weather has curled the edges up a bit, but it's fine.
They are sitting on top of swamp mats, which are sitting on muskeg. Even the mats have hardly any deflection in them.


Each of the 4 corners of all these tanks look like the above photo. They are all 100 barrel tanks.
http://farm4.staticflickr.com/3773/9...39f33dc0_c.jpg

I know this thread is beat to death. But just for future reference.