Weight Limit for a Concrete Reinforced Floor?

Where have you gotten the information "...the floor is made of about 8 inch steel reinforced concrete."?

And more importantly, what does the apartment house management company have to say about this plan? I believe I already know the answer to that one.

I got that from a point in the building where the floor thickness shows but I have no way of getting the plan for the building and no way of knowing how much rebar is in the floor. If it is even close to a dangerous load I won't fill it. At first I didn't think it would be that big of a deal because the pool was cheap and more like a big kids pool but when I saw the volume of water I started to get worried. From all the answers it appears i should not fill it....oh well

M

8,000# spread over 100 square feet= 80 #/ft^2. If the pool is square.

No opinion on the potentail problems encountered by splashed/spilled/leaking water but the floor should support the weight.

I am NOT a civil emgineer. Look up some strength charts on the web to get a feel for it.

I get about 50 ft².

5ft*10ft*2.5ft = 125ft³

125 cubic feet * 62.4 lbs/ft³ ≈ 7800 lbs of water, plus the weight of the pool itself.

8,000 lbs (from OP) / 50 ft² ≈ 160 lb/ft²

So, about 160 lbs/Ft² dead load. (If filled to 5ft X 10ft X 2-1/2 foot depth)

As lyn says, the splashed/spilled/leaking water may also come into play with your neighbors.

Right, the volume would indicate that my guess is off by a factor of 2.

My brain is still fuzzy from the weekend.

Hopefully you didn't miss Mother's Day as I apparently have.

Sheesh, who saw that coming?

I'm just a thoughtless slob. I didn't even send my sister a card for her birthday on Saturday. She's gotten used to it and forgives my thoughtlessness.

Besides, Mother's Day is supposed to be in June, right?

My 96 year old Mom wouldn't know either way. She's off in her own little world, hopefully content with it.

Sorry I forgot to mention. The pool is round with a 5ft radius.

Of course that is a minimal loading condition, as eccentric loading due to wave action and any loading from people and equipment was not considered. also it is not only the load per square foot, but the net load at the support columns and beams (are there beams? there should be) that need to be considered. The floor transfers the local loads to the beams, the beams transfer to the columns, all need to be analyzed. You need to analyze the floor as a slab and look at the density and size of reinforcement in that slab. You need to include all deadloads, and then add in the live loads including the pool and people. The factor of safety you need is 1.7 on the live loads and 1.4 time the dead load. These represent your loading conditions to perform the analysis. You really should retain a engineer for this service, as you will get your A$$ sued off if you cause damage.

I love this site, I really do. If you reread the OP, does anyone here think this person is interested in hiring an engineer? (what engineer would take that job, for God's sake!)

Your reputations as engineers who have a difficult time interacting with reality is alive and well!

But honestly, I love you guys.

I didn't say an engineer would take the job necessarily, but if he was willing to pay for the work, I am sure there would be a number of engineers willing to take the job, it just might cost him. I would suspect someone willing to tear apart a whole floor in a building to install a swimming pool should probably be able to afford the necessary structural analysis, and permitting. If he is just conducting his own little feasibility study he could fairly easily do the analysis himself, and if he thinks it looks close go to an engineer at that point, rather than wasting his money. The first thing he will find out is that it is more about the reinforcement and strength of materials, and not just the thickness of the concrete, that is important in this case.

Don't get me wrong, you can always find a contractor (probably unlicensed) willing to do the work under the table for cash, unpermitted, who will tell you something crazy about the thickness of concrete making it strong enough. Of course the contractor will be hard to find if there is a problem, and if someone gets injured or dies, well then he was just a day laborer who had no idea and just did what he was told. the rel question isn't about the engineer, because many engineers can and would perform the anaylsis for a fee, but what contractor would do the work under written contractor without it being permitted and engineered, the fines and potential liability would kill them and their insurance would not cover them.

Ahm, would not advise such renovation. If ever, I have I'll try to get the spefication and the considered load design of the apartment, see how much is the factor of safety was considered on design, plus structural considerations as where you should locate the pool in reference to existing columns & beams.

Leaks and splash would not be that much factor to consider, there are already good water sealing concrete treatment available in the market, nowadays. It's just a matter of swimming pool design.

The main thing to really consider here is the structural aspect of the building.

Hello lyn & Doorman, Happy Mothers Day you two!

If Doorman has it right at 160#, that is way higher than the normal design load for a residential building.

8" is thick for a recent building, could include a slab and topping. Is it a one-way or two-way slab?

Check your insurance.

You have also to take into account the span between supports for the floor slab. Eight inches sounds too thick for a residential building. Is this apartment building a conversion from some other use? You should ask the building's owner and a structural engineer about this. On wooden floors concentrated loads, like bathtubs, require extra reinforcement or some way of distributing the load more widely.

At the very least, you should consult local, State, and Federal building and occupancy codes. If you live near an engineering school, their library might have copies available to the public. Public libraries in large cities also sometimes keep such things in their Reference department.

Just to add............

If you're wondering what the worst case scenario could be. My answer would be JAIL.

Destruction of property, reckless endangerment and manslaughter are just a few charges that could pop up if your experiment fails.................I'm sure there are others. I hope you're getting my point.

Not to mention, you would be the laughing stock of the entire cell block.

"What are you in for?"

"Oh, I decided it would be a good idea to set up a swimming pool in my 5th floor apartment and it didn't work out so well."

Has about the same effect as having 53 people over for a party with each an average weight of 150 pounds.

However, it still is a very dumb idea. Just image going out and returning to find out your pool had a leak.

Try telling your landlord that your water bed leaked.

That reminds me................I think we've all seen the videos or heard the stories of someone having a party at a condo or apartment, the ones where everybody's drinking and having a good time, and decide to all go out on the deck at the same time..................................and the deck breaks off the building.

except he could still have those 53 people in the pool also, so you end up with the pool loading and he people, plus the loading from the wave action and people clustering.

53 people do not fit in a 10ft diameter pool. ...maybe 25.

Hmmm...the OP posts the question as though he wants to put the swimming pool in his OWN apartment, as opposed to an unsuspecting friend's. Also, there is indication that he intends to fill it with water, which isn't nearly as funny as, say, jello. Or concrete.

or limeade and tequilla

All the preceding notes are good.

Just one more: HOW do you know, that the specs YOU quoted are any good??!??

Since I have no part in it: why you do not build it, and demonstrate to us, why certain dumb*ss ideas are no good??!??

Please have the result's video on Internet. OK??

The building plans might be in the public record, and might possibly give the psf rating of the floor. Then there are some corrections that would need to be made for a concentrated vs. uniform load.

Tornado, You really think this is a good idea?

No, but that doesn't make it impossible, so long as proper considerations are taken, such as secondary containment in case of leaks or splashes.

But then I'm not too big a fan of "can't do" engineering.

Given recent events...

I like that phrase "secondary containment" with emphasis on "containment."

j.

Invite fifty-three friends over and jump up and down in unison in a five foot circle, which somebody watches the floor with a transit... I'd start in a corner.

The calc. seems a bit out? 5ft radius very roughly (quick guess) makes:
3 x 5 x 5 = 75 square feet - make it a cubic foot (for x 62) = 4650 lbs.

If this is correct, only a 2 foot depth will be over 9,000 lbs ? Now for deeper, eeeeekkk!

Many concrete floors (in the UK at least) are not to one depth.
They contain designed recesses to save on cost and weight, and the edge thickness
need not imply overall thickness.
You could drill a few holes all over your floor to find out? (joke)

To cover the costs you could then send those fortunate people living beneath
a bill for their built-in shower services?

Constructively, may I suggest you try and rent the ground floor?
I'm sure many people would be much happier if you did, likely the landlord?
He may even offer you a discounted rent, before he (rapidly) sells the building
or finds another tenent.

jt. (Sorry, I'm in a funny mood today.)

I try to avoid drinking water... fish **** in it.

This is one of the crazier questions I've read here.

1st. Don't do it.

2nd. The term "reinforced" isn't a grade. It simply means it contains steel. Just one 3/8 bar will qualify as reinforced. You'd really need to know how much steel was in it to get solid data.

3rd. (I think someone touched on this) Your floor covers some span. The rating your floor can withstand is also factored in.

4th. You have more than enough "compressive strength" with your floor. As far as shear strength that's holding the floor up...you're gambling.

When I read the OP I couldn't believe what I had read!

Noooooo nooooo noooooo don't you fill that pool inside your apartment!!!! Your floor will most likely collapse and end up pancaking the floors below you. Remember what the World Trade Center looked like when it's floors cascaded down to each succeeding floor below when both towers failed? Your's will be like that, but the collapse will be on a less grander scale. JUST DON'T DO IT. You will be held liable for the resulting damage to the building and it's contents as well as for any injuries and deaths that may occur due to your negligence.

If the water depth is only 2.0 feet, that equates to a live load of 124.8 psf (2.0' * 62.4 pcf). If the water depth is to the brim, that equates to a live load of 156.0 psf (2.5' * 62.4 pcf). And we haven't added in the dynamic loading due to sloshing (*wave action), the weight of human bodies and the dead load of the pool structure itself. Then there's the dead load of the slab itself, which must span to either adjoining bearing walls or beams (which are most likely supported in turn by columns).

BTW, if the building is 15 years old and has a Certificate of Occupancy, then most likely the municipality having jurisdiction required building permits, construction plans prepared by an Architect and/or a Licensed Professional Engineer (hopefully a Structural Engineer), and Construction Inspections. that means that the local town Code Enforcement official/Building Inspector or the City Engineer's Office has a copy of the approved plans on file in their office.....in most instances you can then look up the design live load for the used for the reinforced concrete floor on those plans. You'll usually find that information in the "General Notes" section on the Structural Drawings (usually the drawing sheet number will be a S-1, S-2, S-3, and so forth).

Most state codes require at least a 40 or 50 psf design live load as a minimum for large multi-story apartment and condo complexes (residential....office buildings are another animal altogether)......although some codes, including cities may have larger design live load requirements.

I hope this answers your question(s).

Signed,

CaptMoosie, BSCE/MSCE/PhD, PE

Civil, Structural & Environmental Engineer

Wow this got a lot of attention. Isn't 40 to 50 for a wood building? I'm serious about the 8 inch rebar reinforced concrete floor and it isn't inside, its a rooftop area with plenty of drains. Also there is an 80 cubic foot water tank on the much thinner upper roof with no extra reinforced materials or placement and the neighbors have double that up on their much thinner roof. Btw I don't live in the US so all that documentation is not available. I worked it out to about 115 psf fully loaded no people, round, radius 5ft and manual says 1100 gallons max. It's also a commercial spec building that can be registered as a business or residence. It can't be that crazy!

The only way you can do this is to first consult the architect for the building. Then, upon written approval of the architect, take your plan to the city building codes and get a permit. This assumes that the owner of the building will buy into this as well.

The liabilities for this stunt are way beyond imagination, but the last thing you want is to be held accountable for a disaster of this magnitude. If something goes wrong, and you don't loose your life, you probably will be spending some serious prison time for a list of violations longer than your arm. If nothing else, research what a felony conviction means and how it will ruin your life.

You might also want to add an attorney to the list of professionals you need to consult with.

Others may want you to add a psychiatrist to that list of professionals. However, the last group of people you should use for serious advice on this stunt is us.

Just consider what the consequences of this could be. Even if you pull this off, how will you sleep if sometime later down the road you hear that the roof collapsed on that building? You may never be sure if it was your stunt that caused the building to be stressed to the point that it failed, but you will have to live with that for the rest of your life.

Consider what living with that doubt that your escapade caused loss of someone's life or the life of some little kid. Some things just can't be fixed.

Actually the building department is probably going to want him to consult a engineer experienced in structural design, not necessarily an architect. Architects role is the facade and appearance, even architect have to consult engineers on the structural issues. Now if there is a issues about appearance, historical building or accessibility they may also want a architect. He is also, as he indicated also, so they may not even have a planning or building department.

Yes, but starting there will no doubt cascade into a whole range of people that need to be involved.

A more important point is the liability factor here.

Actually, depending on the site conditins, situation, local requirements, he could find that all he needs is something as simple as a Letter or maybe a set of plans and details signed and stamped by a licensed Civil Engineer. It is possible it could cascade, but unlikely it would cascade to having to have a architect involved, unless it is a historical building, his idea effects the exterior facade, or he plans to impact public accessibility. Likely if there were issues discovered in the course of reviewing the facilities plans they might be related to the structure being very old, modifications, the structural situation is not well defined in the existing plans and/or there are apparent discrepancies. In such a case, The engineer might end up needing a testing laboratory to verify reinforcement and materials strengths, and some jurisdictions may prefer or require a licensed SE stamp the plans or letter instead of a CE. As others have indicated above, it is actually not a very complicated issue as far as the numbers of different types of expertise required, primarily just a Civil or Structural PE and his subcontractors who provide him required information.

Whoever designed the building - be it an architect, engineer, or whatever - is the person who knows. Just look for the name on the print, which should be available at the city building/planning commission.

If that person has retired, then you can take the plans to someone else that is licensed.

Needless to say, in the US that usually means a lot of red tape and probably not much different anywhere else in the civilized world.

"Yes, but starting there will no doubt cascade into a whole range of people that need to be involved."

Agreed.

Isn't this a lot of messing around for an oversized wading pool?

[edit] This thought is only underscored by RCE in #39. It is only a wading pool, temporary per the original post. None of these inspections, reviews, calculations, plan reviews, etc. will be done.

It is a lot of work but it is more of a fun problem now with all the activity! Let me rephrase a bit . Is there a psf level after which someone should get concerned? 40-50psf I have heard for residential wood frame homes, is it different for concrete and rebar... 80?...100? I've had 500 gallon aquarium here without a second thought. At the same time I asked you guys I also asked people who live here ( Taiwan) I'll post their answers soon.

40-50 psf for the floor in a wood framed house seems light considering one man applies about 100 psf to 200 psf just standing. Somethings to consider are where you place the load and proximity to bearing columns or walls, also, as indicated elsewhere there are safety factors for seismic and general safety factors for live loads and dead loads in the room. The strength of a concrete floor has a lot more to do with the reinforcing steel than the thickness of the concrete, though a thicker slab could allow the steel to potentially be placed further from the neutral axis. Concrete is a composite materials constructed onsite, therefore structural strengths can be quite variable, as the concrete compressive strength can vary, and the strength and placement of reinforcement can vary.

The op says 5th floor apartment. Is it a rooftop deck or a fifth floor apartment?

Both. The outside area is a part of the apt, it is a deck but it is fully within the buildings structure no overhang or anything. Think penthouse although it isn't fancy. I wouldn't even consider it except the fact that in the country I live in they stick huge water tanks all over the roofs with no reinforcement and buildings here are made of unusually thick rebar and concrete... it is a commercial spec building. That much I have verified. My roof actually has a 80 cubic foot water tank on 4 posts with nothing under it and no special placement. And I know that because I watched them move it. I am getting an engineer to come by anyway. So much controversy over a kiddie pool.:-)

A rooftop area with plenty of drains?

I think I may have a good alternative. Assuming there's a hose connection up there, just go buy a lawn sprinkler and let the kids splash around in that on hot days. You probably won't end up using much more water than it would take to fill up the pool, and the risk is eliminated.

The problem with the pool idea, is that there could be hairline fractures in the concrete structure. You have no way of knowing.................the weight of the pool could be just enough to set bad things in motion.

Since it's a roof, it probably has less load bearing capacity than the floors below it. The location of the water tank was probably by design, and has been reinforced for that purpose.

What if this apartment is some sort of loft in a repurposed building with, say, a 225 psf floor in it? If the OP were to find out something like this from the local building department, the project might actually be viable! (Don't take this as a suggestion without verifying, though.) (And don't crash the party on the next floor down!)

Tornado is correct regarding re-purposed buildings, such as rehabilitated manufacturing and storage buildings, and sometimes older office buildings.

But it will be costly to verify the RESERVE Live Load carrying capacity of the floor slab, any bearing walls, supporting R/C beams and girders, and R/C columns.

First, the OP must obtain the services of a Licensed Professional Engineer, preferably a Structural Engineer, and a Certified Testing Agency which will conduct field and/or laboratory testing of the concrete under the direction of the PE.

Under no circumstance do you totally rely on the construction plans (if they exist) regarding rebar sizes, spacings and depths because field changes do occur all the time and in a lot of instances (if there was no full time inspection by a NICET Certified Inspector) the Contractor or Subcontractor may have either built the R/C structural elements not to plan & specs or he/she may have cut corners to save money and pad their pocket. Seen it happen all too often!

Also, concrete compressive strength may not have been up to spec or may have deteriorated over time.

The SE will direct the agency to perform either concrete core sampling at designated locations so as to perform concrete compressive tests in the lab to determine the average concrete compressive strength, or he/she may elect to employ several Windsor probe tests to determine the compressive strength(s). The latter is a non-destructive test and achieves very good results if performed by a thoroughly trained and experienced tech who in most instances is certified to perform such testing.

The SE may also direct the agency to perform non-destructive testing of the slab to determine the size of the rebar, their spacing, and their depth throughout the slab, bearing walls, beams, girders and columns. There are several different types of testing employed to obtain these results. I'll not get into describing these tests here for sake of brevity.

Now with the results of the concrete testing the SE can perform analysis calculations to determine the safe allowable live load of the structural elements and compare it to the loads that the swimming pool will impart upon the slab itself as well as any and all structural elements supporting the slab in question.

My gut feeling at this time, due to insufficient information presented by the OP, is NOT to fill that pool because it may lead to a structural failure, possibly even a catastrophic one.

The OP may want to check with the Owner of the building, and/or Apartment Association, and if it's a condo building then check with the condo Association regarding limitations and restrictions that owners/renters may face. Many have restrictions regarding the installation of hot tubs, spas and pools.......big no no's due to structural limitations and possible flooding concerns of the apartment in question, and the apartments below and next door on the same floor. Failure to comply with their rules will get you booted out of the apartment or condo!

The OP may not want to hear this, but I can definitely tell you PFR will have a problem with another Civil Engineer of probably many recommending the OP retain a engineer to analyze the structure.

RCE

I don't have a problem with it, I just think it's funny. Could anyone tell me how I could get my Pathfinder to go 180MPH. Please, nothing fancy.

Fancy is relative to what you are willing to pay. 180 mph is easily achievable under the right circumstances with the proper modifications, dang 300 mph would be easily achievable for the right level of investment. Now being able to turn and control the vehicle, and have other vehicular functions maintained might cost more. What is realistic to Donald Trump might seem unbelievably unrealistic (unafforable) to many other people. It is not necessarily unrealistic to put a swimming pool in an apartment building on a 5th floor, it just might cost more. The question becomes how much more and are the benefits gained worth the cost, and that has a lot to do with the quality of the existing structural elements and facilities. Haven't you ever seen Las Vegas?

well said, and yes I have seen LV. It's wearing some of my clothes.

As yet we don't have anywhere near enough valid information either to rule in or rule out this project. Typical 40 psf residential structures would obviously flunk, but you seem to have heavier construction than that. The question is, how much heavier, and is it enough? If you can't find the original builder, or plans that may have been filed somewhere, it's all a crap-shoot. At the very least, it would be necessary to know where any bearing walls and columns are, and what the span of the floor/deck is. And maybe what the seismic zone of Taiwan is. Turning rectangular wall sections into parallelograms is a big no-no!

I am tempted to suggest that a deflectional analysis might work (even if some structural engineers threaten to kill me). As a rough guide, deflections less than 1/360 of span are good. If you were to install the pool and gradually fill it up, measuring the deflection all the while, you would abandon this idea in case of excessive deflection. BEWARE, this is only an idea, and it may not pass muster. I am not ratifying this project, but I am surprised at all the naysayers, who so far have no more calculations than I do, and for the same lack of information.

I wonder if "can I put a Californian waterbed in my apartment?" would cause such a kerfuffle.

But given, at 2 feet deep, it would probably surpass the mass of a pair of lard-arses, so slumbered - I'd ask the builder, architect, or civil engineer - what they thought.

"I'd ask the builder, architect, or civil engineer - what they thought."

What - about the lard-arses?