DIY Reinforced Floor

[aws2266]

I'm getting a 120g in two weeks and was curious about the weight it would add to my dining room floor. After much research, I found that it will weigh between 1200lbs and 1400lbs with rock and water, and I'm going to need to add some support under it. I want to say that I'm not a professional and while I did consult professionals this is by no means to be a substitute for you doing your own research or hiring someone to do it for you. This is just my DIY story. My dining room is floor is supported by 13ft 2x8 joists spaced 14.5 inches apart. The aquarium is going to run parallel with the joists and sits above a basement with load-bearing walls on each side. The weight of the aquarium is going to be spread over two joists almost exactly center. From my research, I found it wasn't that the aquarium will come crashing through the floor but would cause the joists to sag and that side of the house to become unstable. I decided the best route for me was to add a floor post. This is where I started asking a couple of contractor friends and engineers for their thoughts. The best route was to get a metal plate or bar under the joists supporting the tank. Unfortunately metal is crazy expensive right now. It was going to cost me over $500 for just the metal. My brother who works with aluminum had some extra strength aluminum bars laying around. We did some checking and found that this would be adequate for my needs. I was still a little hesitant using "extra strength" aluminum so I decided to add another support post. I also did some blocking inside and outside the area of the aquarium. That will provide some extra support and reduce any bounce in the floor. In the end, I used two floor posts both capable of supporting 12,400lbs each, and two extra-strength aluminum bars to support the two joists the aquarium will sit on. In all it cost me $180. Here are some photos of it all finished. oh, the floor was a little uneven so we had to setup the bars differently.

 

[Dolphins18]

I did the same thing, 4x steel jacks rated at 15000 pounds each. that was for about 300 gallons of water, so far all is good. I did not use the metal spacer in between the jack and the wood, I just went straight from jack to wood.

 

[SteveMM62Reef]

I’d add bolts into the floor and above, so they don’t walk, from the vibration of trucks going by.

 

[dennis romano]

Your best bet is to sister new 2x8s to the existing joists. Basically, you are turning 2x8s into 4x8s. There are plenty of videos on You Tube.

 

[jdiefenbaugh]

I would sister the joists if you're worried. That being said, it's the equivalent of 6-7 adults, reinforcing isn't necessary for tanks that size in almost all cases.

 

[1ocean]

I agree with your idea but, I would remove the metal between the pole and the wooden floor beam to prevent any slipping incase it shifts a little.
If it does shift a little the metal will help the poles slip out from supporting the floor beams.
I would add something like a 2 x 10 instead of the metal between the floor beams and pole supports and bolt the 2x10 to the floor beams and place the poles to support the beams at the intersections ..
Bolt the top of the poles to the wood.
And also bolt the poles to the floor.
Just how I would do it at if it was my place.

 

[Eldredge]

I am not an engineer, but I’ve done a little building. I think a single post will really only support one joist, and it should be placed directly beneath it. If you want to have the aluminum beam support two joists, I think you need a post on each end of the beam.

 

[1ocean]

Looking at the pictures closer, you really need to lose the metal bars between the poles and wood beams. Also I would either frame a wall and make like a closet or something under the floor area to really max floor support or at least do what Dolphins 18 did and do 4 pole supports .
Doing just one beam is not enough. I would do two adjoining beams to cover the span...
Just a Idea , then if you made a closet or some sort of framed full wall support, you could put your rodi containers,,a sump etc in that basement and run pipes through the floor to your tank.

 

[aws2266]

Thanks for everyone's input. I ended up having a contractor come out and look at it. Not the way he would have done it but he saw no reason to worry. Looks sound. Brought the tank home last week and had it filled up for a couple of days to soak. Really happy with the results.

 

[Duncan62]

I am not an engineer, but I’ve done a little building. I think a single post will really only support one joist, and it should be placed directly beneath it. If you want to have the aluminum beam support two joists, I think you need a post on each end of the beam.

Microlam joists. No posts required. Add 2 and build the tank.

 

[casey012293]

They make bracing to help brace those floor joists to the end board. Right now they only look like they are relying on a few screws through the ends and I’m pretty sure not up to code for even not having an aquarium. Along with the posts you added I would probable finish these off as well.

 

[Greg P]

Maybe it's too late to add this, but in addition to the above suggestions, I'd place a couple square feet or more of lumber under each jack post to spread the load out. Otherwise the point loads will possibly crack the concrete.