Big Tanks and their weight problems?

[Anonymous]

I am intersested in a standard 180 reef ready tank but have questions as to how to go about making sure my floor will be able to support such weight. I recently purchased a new home; it is a split level design with basement/garage/laundry room ect... underneath while the main living area is on the top floor. Now I'm assuming that the total package will wiegh something around a ton or more. And I know what happens when you assume things so I'd like some professional opinions.

Now my question is will my floor upstairs be able to withhold a 180 gallon reef tank with all the "options"(stand/canopy/sump/refugium/lights/200lbs Lrock ect...)2000+lbs give or take a couple hundred?

 

[Anonymous]

told ya....milzed

 

[kparton]

A good idea would be to post your problem on the message boards at doityourself.com. They can tell you what kinds of weight you can bear and will also give you options if you're concerned about it. One thing they are definitely going to tell you to do is to make sure the stand has distributed weight (i.e. not four legs) and that you place the tank perpendicular to the underlying joists. This will spread the weight and ensure that one joist under the majority of the weight will not warp over time.

My tank is just 50G, so it's not nearly as big of a tank. You're probably figuring like me, "surely someone else has done this and it was no problem". I'm think that is right, but it never hurts to ask.

 

[DOGMAI]

That equals out to only 183.33 pounds per square foot. I have said it before and I will say it again I have a house that is 50+ years old with a wood floor and I weigh way more than 183.33 pounds and it holds me just fine when I stand in 1 sq. ft. I am a drafter and I work with a structural engineer and I asked him the same question you are asking and how he explained it to me is how I just explained it to you.

 

[kparton]

Very good point, never thought of the /sqft angle.

 

[DOGMAI]

Sorry that was at 2200 pounds. forgot to tell you that. Even at 2500 pounds it is 208.33 pounds per sq. ft.

 

[Anonymous]

That equals out to only 183.33 pounds per square foot. I have said it before and I will say it again I have a house that is 50+ years old with a wood floor and I weigh way more than 183.33 pounds and it holds me just fine when I stand in 1 sq. ft. I am a drafter and I work with a structural engineer and I asked him the same question you are asking and how he explained it to me is how I just explained it to you.

would it be engineered to hold that amount on every square foot though?

 

[Anonymous]

It seems to me that if your stand evenly distributed the weight, perpendicular to the floor joists (and not parallel), and it was near a load bearing wall (and not in the center of a span), you would be fine.

However, with that said, I'm a bit of a scaredy cat and would definately bolster the supports between the joists just to be safe. I was in a friends new home while it was under construction recently and was shocked at the huge span they had the joists running. I was so concerned that I made him ask the contractor if that size of span was safe. It turns out that it was safe because he upgraded and bought these special wood I-beams. I have talked with some contractors friends of mine since then and those special wood I-beams are apparently amazing. I don't know if you have those newfangled I-beam joists, nor do I know how long the spans are in your house, nor do I know if you are putting your tank on a load-bearing wall or not. I also don't know if your subfloor is concrete, cheap plywood, or OSB. All of these things have an impact (at least for scaredy cats).

In the interest in full disclosure, I'm not in construction---I'm a CPA. However, I did buy the nastiest house in my subdivision, gut it, and turn it into one of the highest appraised houses in the subdivision. When you look at a computer all day, listen to filthy stinkin' rich people complain about how hard they have it because they have to pay so much in taxes, deal with the IRS and various state governmental employees (we're from the government...we have a guaranteed pension...we can never be fired no matter how bad we do our jobs...we're here to help), you just have to swing a hammer or two.

 

[Mogo]

I am tempted to give a heroic answer to your question but not knowing the construction of your house, I would get some professional eyes on it. I THINK the weight will be ok if dispersed properly but the bottom line is 2 tons is a load that should be considered very carefully. With 2 tons, you don't wanna think, you wanna know.

 

[tazdevil]

Depends on what type of support system they put underneath your flooring.

Most newer homes have either the pre-fab wood I-beams, or, the strut system. My house was built with the strut system, and I was told I shouldn't have to worry up to about 300gallon sized tank. Important thing to take note-builder recommended anything above about 100gallons to be sure to be going perpendicular to the struts-not parallel. Reason-being parallel can cause only 1 strut system to bear entire load-perpendicular will distribute load across 3-6 struts. I-beam-not entirely sure, I do know they are supposed to distribute loads much better than the old joist systems though.

If it has the original joist system (2*6's or 2*8's), then I would consult a struct. engineer, you might be ok going perpendicular to those, but I definetly wouldn't go parallel. They would also be able to assist you in designing extra support if necessary.

HTH< FWIW

 

[tkhawaja]

I went through this myself recently. I only have a 100G and my tank was going to be on parallel joists. The answer I got that made the most sense to me was, "I would rather overbuild and be confident then underbuild and be sorry". This is what I ended up doing for my own peace of mind. Whatever you decide be absolutely SURE the tank is level. Check the level as you add water. Even if you have to empty it once or twice, make sure it's level.

So, overbuild and be confident instead of being sorry.

 

[Anonymous]

I hate to bring this out, but there is a difference between a temporary (dynamic) load and perm. (static) load in civil engineering. Almost all load bearing structure can take a higher dynamic load than static load. So you can have 40 people on a porch for a few minutes without problem, but you can't let them stand there for hours with beers and dance around.

It is a complicated issue, and people has to realize that it is not something we can answer all the time because there are so many variable (building code, size of tank, type of stand, material, etc.). No body can take liability over the Internet, and if such peace of mind is desired, it must be brought to certified civil engineer or contractor for review. However, if such seriousness is not necessary, then it is safe to say that it is very rare for a tank to go thru the floor if the tank has less than 20 inch of water, unless something very naive is done.

 

[Anonymous]

I hate to bring this out, but there is a difference between a temporary (dynamic) load and perm. (static) load in civil engineering. Almost all load bearing structure can take a higher dynamic load than static load. So you can have 40 people on a porch for a few minutes without problem, but you can't let them stand there for hours with beers and dance around.

It is a complicated issue, and people has to realize that it is not something we can answer all the time because there are so many variable (building code, size of tank, type of stand, material, etc.). No body can take liability over the Internet, and if such peace of mind is desired, it must be brought to certified civil engineer or contractor for review. However, if such seriousness is not necessary, then it is safe to say that it is very rare for a tank to go thru the floor if the tank has less than 20 inch of water, unless something very naive is done.

How do YOU know the frequency of floor failures. Where do you get your data to say that they are "rare". Does this database also give details of the failures such as floor joists size, condition and direction? I sure would like to see your data.

 

[Carpentersreef]

Regarding floor loads.....here's probably a little more reading than you would like :wink:

http://www.awc.org/technical/spantables/tutorial.htm

Be careful where you place a tank of that size. It can't go just anywhere.
Over a bearing wall would be best.

Mitch

 

[ChrisRD]

Dragoon,

I'm an engineer and I usually stay out of these threads because this is not as simple an answer as "I weigh 200 pounds and don't fall through my floor". This is NOT how it works - that's a drastic oversimplification.

I won't give you a professional recommendation over the internet, but read the link posted by Mitch above, and if you're still unclear or concerned contact a local building contractor, or better yet, a structural engineer. In truth, someone has to see specifically what you are going to do (in person) and what your floor construction/connections look like to give you a 100% answer.

At the very least, with a tank of this size you should stay near a load bearing wall and stay perpendicular to your floor joists.

HTH

 

[Anonymous]

Thanks,

I appreciate your guys comments. I have thought and thought and plan to put in a "closet" downstairs that will give the wife a storage space and give me a load bearing wall to go under my 180. Since my house is an investment and do not want to have a bowed floor or venitlated living room I'll do some more construction.

ChrisRD, and Carpentersreef thanks for your advice the link helps out alot. My floor system is relatively new and holds about 25-30 psf deadload center room. It'll hold 75psf liveload dead center and ect...

ChrisRD, if I were to give you a copy of my plans of the house and the position of the tank in regards to the plans would it be possible to get your professional opinion?

 

[Carpentersreef]

Dragoon,

A closet wall itself is not automatically a "load bearing wall". The best thing to do would be to contact a local truss supplier (preferably the one that supplied the house package) and tell them what you are planning to do. When I'm building a house, changes are made frequently, and it's usually a simple solution (for the truss supplier) to accomodate changes in bearing points.

Mitch

 

[MarkO1]

Dragoon,
I've thought about your post for a little bit and offer the following:
Contact the person who pulled the permits on the construction of your house. He must be licensed and therefore familliar with the local building codes and may be able to help you out. You might also want to check with your local building inspector. There may be some code that I am not aware of that may trigger seeking a permit for a tank over a certain size.
Also, in my opinion, I would be more concerned with 180 gallons of water on your floor than the tank falling into the basement. If for some reason you had a failure, it would be a result of the non-uniform stresses applied to the tank GLASS as a result of deflection. i.e., the deflection would be greater under the non supported corner(s) of the tank than the other corners that were at or near load bearing walls.
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[Mogo]

I guess I should repeat my previous post.
Get a professional in there to have a look. In my house the weight would be fine but I have to fall short of giving any recommendation based on your local (building code/house construction/tank orientation) situation. A 2 ton tank is a beautiful proposition. You NEED to be sure that it doesn't end up somewhere you didn't plan on.

 

[MarkO1]

A 180 gal tank will be nowhere near 2 tons.
Also, all I am saying is if it fails, it will not be due to the floor buckling. It would be the tank or stand failing (you may be surprised at how much (or better yet, how little) wood supports that tank.) Without additional bracing (if necessary) you may notice fatigue which would show up in stress cracks in the plaster, or you may notice a sag in the joist.
The guy who built your house is familiar with it, he's the first guy to go to.
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