How much weight can my floor take?

[Mangimi]

Hi guys, I have a question. Last weekend I bought a waterbox 130.4. I got it used for a great price with a ton of equipment, so don't judge me for asking only now. It's not filled up yet.

Our house is from 2011. The aquarium is placed in front of the staircase to the ground floor. The backside of it is "floating", as in there is a corner that is not connected to the wall. But it has a 4x4 post supporting it. Here's a picture:

The yellow lines represent the joists. The one in the middle is spaced 60cm (24") from the others. The two outer ones are much closer, probably 30cm (12"). The right back corner is the one supported by a post, similar to the one that can be seen on the left. The post on the left does not go through, but it should rest on a large beam that spans the entire floor (90° angle to the front of the aquarium, parallel to the joists). When standing in front of the aquarium, probably 1.5m (5ft) from the front glass is another wall in the ground floor (I would assume it's load bearing, but I don't know for sure). Unfortunately, the plans I got with the house do not show its construction details.

I don't have access to the framing, but I used a stud finder to get an idea of the construction. What do you guys think? Should be strong enough or should I look for a smaller tank? I was quite shocked how big the 130.4 was in real life.

 

[Stealthreefer]

Get a piece of plywood or something nicer to put under it to evenly distribute the load.
You're probably fine, but you never know with new construction these days, 2011 might be old enough they didn't start building housing to the collapsing standards of today. You're not in the US so hopefully that's not a problem there.
If it start noticeably sagging the floor when you fill it up stop and call a carpenter or contractor.
Basically don't start filling it up and walk away to do other stuff.


My dad would be cussing about 24" centers, I can hear him.
I wish maxspect lights like that were the norm in the states, that looks so clean.
That's a good looking place for a tank, I would get some protection on that wood railing before salt start splashing on them.

 

[2020 Worst Year]

get a few of you're mates round like 5 of them gather on the floor jump up and down on the floor if it don't collapse you should be good to go

 

[cwerner]

If you've got 3 joists under the tank you are most likely good to go with just a 130. I'd just make sure that that there are pillar supports at each corner.

 

[Sleepingtiger]

I am not a structural engineer of any sort. Being a carpenter and seeing plywood bend like a twig with as little as 100lbs resting on it, a single sheet of plywood to spread the weight the weight of the tank is insufficient. 130 gallons total plus the weight of rock, sand, aquarium and stand. You are looking at 1500 lbs or 700kg.

If you want to spread the weight out, you will need to build a platform using 2x4 or 2x6.

 

[Mangimi]

The floor in that corner unfortunately is not very level, so I'm afraid using a sheet of plywood underneath is gonna cause more problems than it would solve. The weight lasts on 26 of those little feet, so less than 30kg (66lbs) each.

I guess I'm just glad no one jumps and says: heck no!

24" inch spacing is normal in Europe as far as I know. The floors are rated to hold 150kg/sqm or about 30lb/sqft (if I converted that correctly). The three joists should be pretty much bang on under the tank. We just placed it by eye, but got lucky. I think I'll just fill it up once all the equipment is clean and see what happens (hopefully nothing).

Please keep the comments coming

 

[2020 Worst Year]

The floor in that corner unfortunately is not very level, so I'm afraid using a sheet of plywood underneath is gonna cause more problems than it would solve. The weight lasts on 26 of those little feet, so less than 30kg (66lbs) each.

I guess I'm just glad no one jumps and says: heck no!

24" inch spacing is normal in Europe as far as I know. The floors are rated to hold 150kg/sqm or about 30lb/sqft (if I converted that correctly). The three joists should be pretty much bang on under the tank. We just placed it by eye, but got lucky. I think I'll just fill it up once all the equipment is clean and see what happens (hopefully nothing).

Please keep the comments coming

i see a downstairs what is down there can you not put it down there?

 

[Subsea]

130G times 8.4 lbs per gallon is about 1100 lbs. That’s five big men.

With a footprint of 4’ by 2’ equals 8 square feet

2018 INTERNATIONAL RESIDENTIAL CODE (IRC) | ICC DIGITAL CODES

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.

codes.iccsafe.org

International residential building code says 30 lbs/sq ft

With respect to uneven floor, build platform to eliminate uneven tank.

Considering where this is, what structure is underneath the second story floor at stairs? Or, on bottom floor, what supports ceiling where aquarium sits.

 

[Sleepingtiger]

130G times 8.4 lbs per gallon is about 1100 lbs. That’s five big men.

With a footprint of 4’ by 2’ equals 8 square feet

2018 INTERNATIONAL RESIDENTIAL CODE (IRC) | ICC DIGITAL CODES

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.

codes.iccsafe.org

International residential building code says 30 lbs/sq ft

With respect to uneven floor, build platform to eliminate uneven tank.

adding to what Subsea said. If you are building a platform. Make sure to build the platform so that the frame of the platform runs perpendicular to the floor joist.

 

[Dom]

The location is stunning! I love the spot and would want to make it work where it is.

In my view, the first thing to consider is the total weight of the tank when operational. I'm in the US, so I am working in imperial.

( Tank 96 gallons ) x ( About 8.33 pounds ) = 799.68 pounds.
( Sump 30 gallons) x ( 8.33 pounds ) = 249.9 pounds.

So the total water weight is 1049.58.

We also have to consider water displaced by equipment. And while this will reduce the total volume of water and reduce the total weight of water, we now have to add in the weight of the equipment in the tank, the weight of the tank and stand as well as the weight from Aquascaping.

If this were my system, I'd work under the assumption that the finished system will be in the 1500-2000 pound range (Its probably less).

We have 3 beams which run perpendicular to the tank itself, which is what I'd want if it were my system.

And if I understand your description, those beams are connected to the beam the runs parallel to the back of the tank and a wall approximately 5 feet away in front of the tank. In my mind, this amounts to all of this weight being supported by 3 beams approximately 5 feet in length.

I think the answer lies in the dimension of the beams. if they measure 2" x 12", I think you will be ok. But I would open the ceiling below and double up on the beams to play it safe.

Again, I think the spot is perfect! I would do what it takes to keep it there with the peace of mind that it is structurally stable.

Good luck!
Dom

 

[Mangimi]

Hi again and thank you all for your replies.

Yes the spot there is perfect for an aquarium. It's just 150cm wide (59") and really doesn't fit anything else there. It's also in the kitchen/living room, so it can be seen from the couch as well from the kitchen table. Downstairs are just bed-, bath- and utility rooms. We don't spend much time there.
We had our small 25G AIO standing on the same spot since March, but that looked a little lost. But my wife loved watching it during and after pregnancy.

Anyway, I don't want to put anything between aquarium and floor, I hope that the floor is strong enough. It's our house and if we get small dents in the floor, so be it.

The joists are most certainly 2x8 or 2x10 as the floor is just 30cm/12" thick. What really worries me is the yellow line below. This is from the backside of the tank. I know a stud finder isn't the best tool for it, but for what it's worth: It seems the joists lay on top of two 2x4s, which then rest on the vertical post. I'm sure it's all build to code. There are about 20+ houses of the same make in the neighborhood (I think it's a modular house).

We have taken measurements from the top of the tank to the ceiling above. We want to test fill it with freshwater and see if the floor will give. I'm sure it'll move a few millimeters due to the selv leveling matt and the feet settling. But if it goes down by 5mm or more, I think it's too heavy.

 

[StripeCore]

Hi guys, I have a question. Last weekend I bought a waterbox 130.4. I got it used for a great price with a ton of equipment, so don't judge me for asking only now. It's not filled up yet.

Our house is from 2011. The aquarium is placed in front of the staircase to the ground floor. The backside of it is "floating", as in there is a corner that is not connected to the wall. But it has a 4x4 post supporting it. Here's a picture:

The yellow lines represent the joists. The one in the middle is spaced 60cm (24") from the others. The two outer ones are much closer, probably 30cm (12"). The right back corner is the one supported by a post, similar to the one that can be seen on the left. The post on the left does not go through, but it should rest on a large beam that spans the entire floor (90° angle to the front of the aquarium, parallel to the joists). When standing in front of the aquarium, probably 1.5m (5ft) from the front glass is another wall in the ground floor (I would assume it's load bearing, but I don't know for sure). Unfortunately, the plans I got with the house do not show its construction details.

I don't have access to the framing, but I used a stud finder to get an idea of the construction. What do you guys think? Should be strong enough or should I look for a smaller tank? I was quite shocked how big the 130.4 was in real life.

you can place it on a plywood to evenly distribute the weight then it wont topple over.

 

[Mangimi]

Thanks for your reply, however, I don't see how a sheet of plywood would significantly contribute to the strength of my house? I also don't want anything under the tank as I said above.

 

[Gill the 3rd]

You're fine where you show it and that is a good location. You are at the end of the joists and right near a column. For a 100 gallon tank I wouldn't worry at all. You can skip the plywood under the tanks, your subfloor will distribute the weight.

 

[Dom]

Thanks for your reply, however, I don't see how a sheet of plywood would significantly contribute to the strength of my house? I also don't want anything under the tank as I said above.

Yes, I wondered this myself. If the tank is being placed on a wooden floor, how is the addition of a piece of plywood between the tank and floor help?

I'm not trying to be difficult, just want to understand.

 

[Paul B]

That location for that tank is fine. You can also park your car there. It is supported by that 2X8 and the floor beams would be at least 2X6 but probably larger. I am not an expert on European construction but worked construction in New York for 50 years.

 

[BrokenReefer]

If that 4x4 shares the load to the floor/slab below, you'll have plenty of strength in the floor/joists. Think about the stairs/landing above it, that load is placed directly on the 4x4 which is lag bolted to the "middle" floor 4x4. If the floor was truly floating and you weren't sure how the cantilevered load was connected to the structure, then I'd be more concerned but this location I wouldn't be worried about at all.

 

[jda]

I would put a tank twice that size there and never think twice about it.

BTW - IRC says something like 40 psf for an entire room, minimum. They do not mention or cover smaller areas and the like. These are also minimums. Put both of your feet together and stand on the floor - this is about one square foot, or less. A 175lb human would collapse in a true 40 psf floor and they don't even budge. I don't know if IRC is the standard in the EU, but it does start with International. 300 gallons is my breaking point on floor joists that are running perpendicular with the tank - so like a 240g and 60g sump without even thinking twice about it.

 

[Mangimi]

So we've filled it up yesterday with tab water. Then we figured out that the floor is bouncy. Like really bouncy. It's just that few sqft between the staircase and the load bearing wall in front of the aquarium.

One firm step and the aquarium formed ripples on top. A lot of them lasting for as long as half a minute. It will also shake the floor when wobbling on the aquarium a bit. So when cleaning the glass for example, the water would start to splash and that would make the floor swing in resonance.

I measured from the rim to the floor and from the rim to the ceiling, but the floor didn't give at all. The leveling mat gave about 2mm.

We removed the water and it's still quite bouncy. There was a crack in the sheet rock under the middle floor joist's cross member. We feel like it has godden wider, but I forgot to measure it before and after.

Honestly, to see about 1500lbs shake like that is just terrifying. I nearly pooped my pants, that's for sure. I don't think we could ever sleep with that amount of bounce. My office is upstairs, so I walk past there every day, multiple times a day. Quite swiftly. Also once our son can walk, I don't want to be one of those parents that tell him "always be careful when walking past the aquarium because it shakes too much".

Gonna figure out how to go from here. It's really a bummer, but I don't think we could sleep at night like this.

 

[drich0365]

I've been where you are and ended up moving my larger aquarium to the the basement in the past after it seemed sketchy.

I recently decided I wanted a Peninsula 4820 in my office and decided this time to hire a structural engineer to sign off on it as worrying about the weight/water damage that comes with larger aquariums detracted from me enjoying the hobby as much.

This has additional benefits of ensuring you have proper documentation (signed/stamped letter from a structural engineer) for insurance in case the worse case scenario occurs such as water or structural damage.

For what it's worth (every home is built differently) it was signed off/stamped with no hesitation sitting on the first floor over three 16" O.C wooden I-joist's 11' foot span against a load bearing wall.

For me it was worth the piece of mind and easing the concerns of my wife.