Do I need floor jacks?

bcarl77 · May 4, 2019

Hi all,

I will be installing a 130gal aquarium in our home later this year. We have a raised floor with crawl space as our foundation. I have a picture of how the current tank sits. The new one will sit in the same place

The tank runs perpendicular to the floor joists. And behind the back wall we have a solid concrete support. Here are some pictures from under the house.

Do I need any floor jacks? I will leave my opinion out of it until someone with some experience chimes in! Thanks in advance!

raylinds · May 4, 2019

I am by no means an expert but have recently researched my own similar situation. It looks like the wall it is up against is load bearing- is that correct? How far apart are the floor joists? How long is the tank? In my research I learned these are important factors.

Billdogg · May 4, 2019

It's a crawl space, so it's not like you would lose any usable space by putting in a floor jack or two. As cheap as they are, I'd go ahead and do it even though it's probably fine without. Make yourself a sandwich of 2x6/3/4" plywood/2x6. glue and screw it together and use it as a header of sorts for the jacks. Overbuilding rarely hurts anything.

But I gotta ask - what's with the fence? something in there trying to escape??? Because I need to warn you - your fish will go right through those bars!

bcarl77 · May 4, 2019

Billdogg said:
It's a crawl space, so it's not like you would lose any usable space by putting in a floor jack or two. As cheap as they are, I'd go ahead and do it even though it's probably fine without. Make yourself a sandwich of 2x6/3/4" plywood/2x6. glue and screw it together and use it as a header of sorts for the jacks. Overbuilding rarely hurts anything.

But I gotta ask - what's with the fence? something in there trying to escape??? Because I need to warn you - your fish will go right through those bars!

Ha! This is kinda what I was thinking as well. Floor jacks wouldn’t hurt, other than an afternoon in the crawl space.

Fence is to keep our little puppie from getting curious with the cords! He can be a monster, his nickname is jaws!

ChuckD76 · May 4, 2019

Billdogg said:
It's a crawl space, so it's not like you would lose any usable space by putting in a floor jack or two. As cheap as they are, I'd go ahead and do it even though it's probably fine without. Make yourself a sandwich of 2x6/3/4" plywood/2x6. glue and screw it together and use it as a header of sorts for the jacks. Overbuilding rarely hurts anything.

But I gotta ask - what's with the fence? something in there trying to escape??? Because I need to warn you - your fish will go right through those bars!

+1 to just getting the floor jacks.
If you don't you'll always wonder if you should have and if you do it won't hurt.

As for the fence, that is obviously the perimeter of the "My Space" which, at least in my home is forever under threat of shrinkage due to my wife saying "I'm just gonna put this in here for a while."
Webster's defines My Space as "an area in which the actions of the owner are immune to judgement from significant others, spouses, partners and other household members but which must be clearly delineated from "Our Space" in order to be legally and lawfully used and maintained."

Obviously (judging by the outlet) the OP has electrified his perimeter fence in order to comply with any and all applicable local laws.

Gonebad395 · May 4, 2019

Tbh I build structures all the time. The start of my working life it was houses now 25 years down the line high rises and steel mills. The way the tank will set on the floor and how close it is to the load bearing wall you won’t need jacks. The floor joists will be able to carry the weight fine without any deflection.

ca1ore · May 4, 2019

There are two things to worry about with floors: catastrophic failure and gradual deflection. Folks seem to worry about the former but not so much about the latter. I happen to think that the latter can contribute materially to tank failure in the future. 130 gallon tank just isn’t that much; 1,000 lbs. give or take. Your floor will handle that fine with almost no chance of catastrophic failure. Whether the floor will deflect at all is less clear (probably not). I read accounts all the time where folks say the tank was level empty but out of level when full. That’s a problem and suggests floor deflection. I am OCD about making sure that there’s unyielding support under my large tanks all the way down to the slab/ground. If it were me, given how easy it would be to add jack posts in your situation, I’d put one under the protruding corner of the tank.

Plus, when/if puppy evolves to kids, having absolutely no ‘bounce’ in the floor near the tank is awesome peace of mind.

bcarl77 · May 4, 2019

Thanks everyone this was super helpful. Sounds like the consensus is to add floor jacks for an extra layer of comfort. I am thinking to would suffice. Since its dirt underneath how and I ensure they are level.

Gonebad395 · May 4, 2019

See there lies your problem unless you compacted the dirt and then placed concrete blocks to put the jacks on these jacks are going to be useless. If the tanks weight started to make your floor sag which I highly doubt it will the only way this jacks are going to help is if they are on small piers poured into the ground any weight put onto those are just going to push them into the ground.

bcarl77 · Jul 3, 2019

So I know this is a little dated. I drew a picture of how it would sit and measurements of the floor/joists. Also is a picture of the beam that would sit roughly a few inches off.

Cherie cook · Jul 3, 2019

Following. Gotta love a thread that starts..”do I need floor jacks” lol!

Scorpius · Jul 3, 2019

If you're this worried contact a structural engineer.

bcarl77 · Jul 3, 2019

Scorpius said:
If you're this worried contact a structural engineer.

Hoping someone here with relevant experience would help provide some guidance. I felt the drawing I made was a better representation than what I previously posted. I will get a structural engineer involved if it was questionable. At this point I am not sure.

theMeat · Jul 3, 2019

No you do not need jack posts.
It gets rather complicated. Your floor should be able to handle 40lbs per square foot. That’s not to say only 40lbs on one square ft, but 40lbs on every single square foot at the same time. That’s a lot of weight.
With the tank close to support wall, perpendicular to beams, it not a problem, at all.

Gonebad395 · Jul 4, 2019

bcarl77 said:
Hoping someone here with relevant experience would help provide some guidance. I felt the drawing I made was a better representation than what I previously posted. I will get a structural engineer involved if it was questionable. At this point I am not sure.

You seem to want to hear you need floor jacks, Again you do not. I’m not going to rewrite what has been written you can go back and read it in a nut shell it almost all says you do not need floor jacks. I think you are putting to much worry into it. And if you are worrying this much about this wait until you add water to this tank. There is so much that will and can go wrong in the start like water chemistry, temp, lighting, coral growth what fish to buy your head will explode. Again you don’t need them your tank will be fine enjoy it set it up fill it up. I build big stuff for a living kinda know what I’m talking about.

Mastiffsrule · Jul 4, 2019

Gonebad395 said:
You seem to want to hear you need floor jacks, Again you do not. I’m not going to rewrite what has been written you can go back and read it in a nut shell it almost all says you do not need floor jacks. I think you are putting to much worry into it. And if you are worrying this much about this wait until you add water to this tank. There is so much that will and can go wrong in the start like water chemistry, temp, lighting, coral growth what fish to buy your head will explode. Again you don’t need them your tank will be fine enjoy it set it up fill it up. I build big stuff for a living kinda know what I’m talking about.

+1

snorklr · Jul 5, 2019

is that portion of the foundation you show directly under the wall behind the tank?....since half the folks here say you dont need anything here's a compromise....lay a pressure treated 2x6 on the lip of the footing...go off that on a 45 degree angle up to the floor joists with more 2x6's...through bolt them to the side of the joist...they should come out almost 2 foot at their end...quick, easy, no digging or concrete

bcarl77 · Jul 5, 2019

snorklr said:
is that portion of the foundation you show directly under the wall behind the tank?....since half the folks here say you dont need anything here's a compromise....lay a pressure treated 2x6 on the lip of the footing...go off that on a 45 degree angle up to the floor joists with more 2x6's...through bolt them to the side of the joist...they should come out almost 2 foot at their end...quick, easy, no digging or concrete

The tank will sit a few inches off the interior foundation wall. This is an option I have considered as well.

N2950H · Jul 5, 2019

Sorry to hijack, but would any of the answers above change if the wall were not load bearing? I have a very similar setup but don't think my wall is load bearing, and I'm going to be putting in a waterbox frag 80 (2x4x1) which I estimate to be around 800lbs, or 1050lbs when I'm standing near it.