240G - Floor Joists?

[96TL]

Hi all.

I’m planning a 8x2x2 240g reef. It’s going on my 1st floor up against an exterior wall, perpendicular to the floor joists. The floor there is porcelain tile.

The joists underneath are engineered 2x12 I-beam style, 16” apart. The exterior wall there is made up of block.

The tank will span across at least 5 joists, possibly 6 depending how it lines up. Should I get a structural engineer to take a look at it? I’m thinking it should be fine, but I don’t want to cause any problems down the line.

Thanks.

[96TL]

Here is a photo from the basement.

[ReefMaster48]

I would bet that its fine. But that's a big bet to take. Safest route is to have someone look at it and let you know. Maybe you'll find out you can get a bigger tank! lol But in all seriousness, 5 joists with a 240 on top, by the foundation shouldn't be a problem; but I would really get someone to look at it. Spend a tad bit of money to get it checked, and you can tell the wife that you were right! lol Thats worth it right there

[96TL]

Originally Posted by ReefMaster48

I would bet that its fine. But that's a big bet to take. Safest route is to have someone look at it and let you know. Maybe you'll find out you can get a bigger tank! lol But in all seriousness, 5 joists with a 240 on top, by the foundation shouldn't be a problem; but I would really get someone to look at it. Spend a tad bit of money to get it checked, and you can tell the wife that you were right! lol Thats worth it right there

I’m already pushing it with the wife for the 240 lol.

I think I will reach out to an engineer. I’m just worried that to cover himself he’s going to get me to spend money reinforcing when it’s not really needed.

I forgot to mention to house was built in 2006.

[mpsteve]

Your good man. I have a 200g marineland sitting on regular 2x10 16 on center I think I’m on three joist and it’s solid. Those engineered 2x12 can take way more. And it the foundation taking the load anyways


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[Frogmanx82]

If you’re across 5 joists against the wall especially, you won’t have an issue.

[ReefMaster48]

Originally Posted by mpsteve

Your good man. I have a 200g marineland sitting on regular 2x10 16 on center I think I’m on three joist and it’s solid. Those engineered 2x12 can take way more. And it the foundation taking the load anyways


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I think your prolly good then. I haven't had a big tank like that on floor joists, but I think plenty of other have had success. I just haven't had the chance.

Are you any good with DIY stuff?

You can support the joists from underneath with a 4x4, 4x6, or 6x6, with the bottom of the post sitting on a concrete block. Similar concept to the attached pic. Again, you probably don't "need" this, but it may make you feel better. That's all that a engineer would want you to do anyway.

[JTL]

There are probably some tables online that can give you information but as I recall a double 2x6 will support 700 lbs per lineal foot and the engineered beams are at least as strong. I once had a 7" tank on a floor constructed of single 2x6's and it was not a probem.

[mcgyvr]

In general...

Multiply area of the room in sqft by 40psf
If total tank weight plus total weight of any furniture/people,etc.. in that room is less than that then you are good to go..

example..
10ft x 10ft room = 100sq ft x 40psf = the floor can support 4000lbs..

[joesig]

I would add support couldn’t hurt.
Especially since i see what looks like a water, gas and vent line all underneath.


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[96TL]

Originally Posted by joesig

I would add support couldn’t hurt.
Especially since i see what looks like a water, gas and vent line all underneath.


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Yes there’s a lot going on in that area. Main gas line, main water line, radon pipe, hvac ducts. It’s busy there!

Thanks for the replies everyone. I’ll look into the floor jacks.

[96TL]

Originally Posted by ReefMaster48

I think your prolly good then. I haven't had a big tank like that on floor joists, but I think plenty of other have had success. I just haven't had the chance.

Are you any good with DIY stuff?

You can support the joists from underneath with a 4x4, 4x6, or 6x6, with the bottom of the post sitting on a concrete block. Similar concept to the attached pic. Again, you probably don't "need" this, but it may make you feel better. That's all that a engineer would want you to do anyway.

That looks like a pretty easy setup. Where would those jacks go? Near the front of the tank?

[davocean]

Originally Posted by mpsteve

Your good man. I have a 200g marineland sitting on regular 2x10 16 on center I think I’m on three joist and it’s solid. Those engineered 2x12 can take way more. And it the foundation taking the load anyways


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Agree, those are amazingly strong, though a few bucks given to an engineer to do calcs never hurts, it's a quick calc given that pic and specs, but as a contractor if that were my own home I'd feel comfortable w/ it.

[ReefMaster48]

Originally Posted by 96TL

That looks like a pretty easy setup. Where would those jacks go? Near the front of the tank?

Bingo, Yup! The back of the tank will be almost right on the foundation, so that's the support, then the new support would go x inches (width of tank) away from the wall. You don't have to use jacks, though they work great, any type of wood post would work fine.



mcgyver, Great tip! Ill be using that in the future too!

[Hal]

First, you'll probably be fine if you do nothing. A cheap way to tell is to measure the floor deflection after you've filled the tank. If it's less than 1/8 of an inch you should be good. Use a tape measure or string line in the basement to do this.

FYI I'm setting up a 250g on parallel joists, although I have a steel I beam running perpendicular to the tank about 1.5 feet in from the left edge of the tank.

If you don't mind the space they take up in the basement, a floor jack/column is by far your best bet. These things are beasts and I wouldn't even bother with any type of structural engineer if you do it. Just make sure to reinforce the floor either with a footing or put down a steel plate under the column to distribute the weight evenly across a greater area. Footer is better, but a steel plate will still work. Put the column under the front corners of the tank, one on each end.

If you don't like the columns in your basement you have two choices:
1. add additional joists under your tank. Since it looks like your joists are exposed that shouldn't be too difficult. If you really want to over-engineer it throw in a steel i-beam as one of the additional "joists".
2. add a "strongback". In essence, find a 3/4 inch sheet of plywood and screw and glue it to the bottom of the joists under the tank. Don't nail it as you won't get as solid a connection and the nails could pull out. Go across 3 or 4 joists to add additional reinforcement against any twisting of the joists (which is unlikely in the first place, but it doesn't hurt). Mechanically, if you have engineered wood joists (solid top and bottom and particle board between them in the overall shape of an i-beam) all of the strength comes from the thickness of the top and bottom solid pieces. By increasing the thickness of the bottom by 3/4 of an inch you add approximately an additional 25% load bearing capacity (I had an engineer run the numbers for me.) Same idea if you have solid 2x12 wood as joists. The thicker it is (top to bottom), the stronger it is. This is the option I picked for my situation.

[outy]

Originally Posted by 96TL

Hi all.

I’m planning a 8x2x2 240g reef. It’s going on my 1st floor up against an exterior wall, perpendicular to the floor joists. The floor there is porcelain tile.

The joists underneath are engineered 2x12 I-beam style, 16” apart. The exterior wall there is made up of block.

The tank will span across at least 5 joists, possibly 6 depending how it lines up. Should I get a structural engineer to take a look at it? I’m thinking it should be fine, but I don’t want to cause any problems down the line.

Thanks.

Measure the Ibeam in the center of its span after the tank is installed, That is the only way to know for sure.

If they drop even a 1/4" then I would use a jack and add required support.

As it is it will support it, how well is what the measurement is for.

[outy]

Originally Posted by Hal

First, you'll probably be fine if you do nothing. A cheap way to tell is to measure the floor deflection after you've filled the tank. If it's less than 1/8 of an inch you should be good. Use a tape measure or string line in the basement to do this.

.

LOl exactly, sorry didn't read this.

[Frogmanx82]

I can’t see how this is possibly an issue unless you were in the center of the room. As close to wall as you are there won’t be anything to measure. I have a 150 running parallel to the joists as a room divider so I doubled the joists underneath when I build the house so it sits on 4 joists spaced 6 inches apart. It dropped about a quarter inch from the wall side to the center of the room but has been there 25 years.

[ca1ore]

I think there's next to no chance of structural failure, but I always worry about deflection causing a seam to pop. If it were me, I'd put 2 or 3 jack posts under the front edge of the tank. Easy and cheap, particularly in a rough basement space.

[NASAGeek]

Originally Posted by ReefMaster48

I think your prolly good then. I haven't had a big tank like that on floor joists, but I think plenty of other have had success. I just haven't had the chance.

Are you any good with DIY stuff?

You can support the joists from underneath with a 4x4, 4x6, or 6x6, with the bottom of the post sitting on a concrete block. Similar concept to the attached pic. Again, you probably don't "need" this, but it may make you feel better. That's all that a engineer would want you to do anyway.

This is the right approach in my humble opinion. My 240g weight 480lbs... just the tank.... 300lb sand... 1600lb water... 50lb salt.... 300lb live rock... 100 stand... that's close to 3000lbs.... and that's in a 12 to 16 sqft area. Over 200lb/sqft.....

Put the floor jacks in.....

Again, my humble NASAGeek opinion.

Mark

PS... I'm not a structural engineer... but I do have a couple engineering degrees and I did sleep at a Holiday Inn. Hope that helps.

[mcgyvr]

Originally Posted by NASAGeek

Again, my humble NASAGeek opinion.

Mark

PS... I'm not a structural engineer... but I do have a couple engineering degrees .

Just a story.. Not targeted at you at all (well.. unless you were this guy )

I had an "Engineer" from NASA call me once and he told me we shipped him the wrong fuse because it said 300VDC on it and he was using it in a 48VDC distribution panel.. He said that the fuse would never work to protect his equipment..

I started discussing with him how thats the maximum voltage the fuse is rated UP to and its the current that causes the element to blow due to i^2r Joule heating..blah blah blah... and he got very frustrated then hung up after stating "thats not how it works in my book son.. I'll call your competitor to get the correct fuse.."

[JoeMomma]

For my 220 (6x2x30") we had our builder double up the 5 joists located right under the tank. I can sleep easy knowing my tank won't go through the floor.

[10Seconds]

I dont know your span but those TGIs with the plywood subfloor on it will hold a lot. As in the whole second story of the house plus a roof and snow load etc.

I have clients worry about this stuff all the time, pool tables, water beds, aquariums, etc. Most of the time it is a non issue.

One thing to check is the deflection. The TGIs will deflect a certain amount and still be within their acceptable strutual limits. However, you personally may not find such a deflection acceptable.

If this was my house I wouldnt even be worrying about the present scenario at all.

[davocean]

Originally Posted by JoeMomma

For my 220 (6x2x30") we had our builder double up the 5 joists located right under the tank. I can sleep easy knowing my tank won't go through the floor.

For many people this seems the easy answer, especially on common frame construction, but keep in mind it's only as strong as your connection/fasteners to ledger or beam, sometimes all people are doing is just adding weight, and on these type of joists you can actually weaken them by over nailing/making added connections.