Building Load Calculation

Get an architect?

You might start by checking the local and state codes for structures. However, I think before you can do anything you need a licensed architect for any commercial building. Even if it is private, the liabilities far outweigh the cost of having a licensed person do the work. At least if something does go wrong (and he is bonded) he assumes the risk, not you.

If this is a purely academic project that is only theoretical, then you might check out a local university that teaches structural engineering and visit their library (and talk to students and faculty).

Just a barn for storing cotton seed hulls, not holding a democratic debate.

Okay. If it collapses and your neighbor's kid is in there, well, how well are you insured? If the answer is very well, how well will you sleep at night afterward?

Just remember that there are more lawyers waiting to graduate law school now than there are practicing today.

Here is a start Jasons;

http://www.toolbase.org/PDF/DesignGuides/ResidentialSteelLoad_SpanTables.pdf

Its focus is more on supporting floors, but it should give you a better idea.

At work I often get asked the question "How much pressure can I put in this pipe?"

To which I answer "I can tell you if you can tell me the following --Bending moment, applied torque, overhung load, thermal expansion stress, dead loads, live loads, stress concentrators, governing code requirements, safety factors required by those codes, corrosion allowance, erosion allowance etc etc etc."

You get the idea, and your situation is more complex!

In theaory spanning this gap is no problem, you just need a deep enough beam to do it. If the beam is not stiff enough, you run the risk of water pooling on the roof which will result in collapse. There are a couple of famous cases of this happening to stadium roofs that I have seen on tv.

You DO need an architect as you need to consider things like this, wind loading (potentially huge forces),the weight of the roof itself, local code requirements and safety factors yada yada yada in order to be able to size the beam correctly. After that you need to consider foundation strength to control all these loads.

Considering what a building this size is going to cost to construct, it makes sense to pay an extra couple of percent to a qualified architect to ensure it doesn't collapse two weeks after you put it up!

Run your bar joists across the 25' span.

It appears that nobody knows the answer. If I wasn't concerned about my neighbors I wouldn't be asking the question. An architect is nothing but a glorified draftsman. They may know the answer but the not going to tell you because their not a "structural engineer". AND sometimes you may want preliminary estimates to see if your going to do the project before going to overpaid draftsman. I thought this was a site for information not opinion.

If I was to build a paper airplane to carry ten people, how much paper would I need?

The quality of the question determines the quality of the answer.

If you don't like the FREE opinions expressed here, why don't you go PAY for the information that you NEED?

Oh, sorry, I forgot, an architect is nothing but a glorified draftsman, and I suppose that a structural engineer is just a kid playing with large building blocks.

Here, for FREE is the single most important equation you need to know to design your hundred foot beam.

(BD³)/12

No, its not an opinion, its a fact. If you don't know what it means or how to use it, why don't you do a structural mechanics course and find out for youself, instead of being p!$$y with the people who took time out from their days to try and answer your oh so important question?

Have a nice day, and I hope the roof doesn't fall on your head.

IPG

"If I was to build a paper airplane to carry ten people, how much paper would I need?"

How much paper WOULD you need??

LOTS !!!!!

If you'd actually attempt to build such a structure based on the advice of an unknown individual on the internet then you're a fool.

Do you have ANY idea just how big a beam is needed to support the live load of what you're proposing?

Architects are just glorified draftsmen? What nonsense.

Try building this without accurate information from a professional engineer, and you just may kill someone-

Why don't you pull your horns in and get in touch with a commercial metal building manufacturer? They can give you an accurate quote on price.

He's probably closer to the truth than you. An architect is not an engineer. Any load bearing calculations must be signed off by a licensed engineer, not a licensed architect.

Anyone can be the architect in designing their own home or barn. They will just need to have a licensed structural engineer 'sign-off' on the drawings.

Thank You

someone that understands

Pal, you haven't a clue. Engineers do not as a rule design structures.

This is the purview of architects. As far as anyone wanting to design their own house, and merely having a engineer stamp off on it, wrong again. Said person is not doing the job of an architect, for the simple reason that they aren't an architect.

It's no simple matter to find an engineering firm that will approve the construction drawings of an amateur, as the structural integrity of a building is not strictly determined on the basis of live and dead loads, and beam strength. Architects by law follow the guidelines of not only architectural standards, but the NBC as well as as state and local building codes, that most amateurs are, if not unaware of, at the least do not have the knowledge of how these should be incorporated into the design of a structure.

Someone needs a refresher course in reading comprehension. Never said engineers, as a rule, design structures. I said licensed engineers sign-off on designs.

You're right I have no clue. My father was a Civil Engineer who worked many years for one of the largest firms in Pasadena, CA. He 'designed' many bridges out there in the '60s while in their employment. He later started his own firm back in my hometown where I worked for him through high school and again after leaving the military. During this time he 'designed' many homes and even a Mississippi-style river boat back in the '70s to run the Colorado River that is still in operation in Lake Havasu, AZ. I thought I would throw in the design part although I agree with you as a rule they don't. They let the draftsman follow guidelines and codes, then approve the work.

I like the part about how architects, by law, follow the guidelines of not only architectural standards, but the NBC as well. The one part you left out was who wrote the guidelines and codes that they follow. Let me take a guess, "Engineers".

Here is something as present I am going through that applies;

Picked out a 'On the Boards' drawing from a renowned Architect out of Litchfield Park, AZ for my 'dream' home. Unfortunately I want to build out of foam concrete instead of wood. This architect is only capable of designing in wood, so his firm is not capable of altering drawings. County's only requirement is that drawings are signed off by a structural engineer, but firm is not capable so I would be required to buy their drawings, have them converted by someone who specializes in concrete and approved by a structural engineer. So I guess you're absolutely right, I have no clue!

You actually got good information. Listen to it. Many of us on here have decades of experience in various work and many of us will never give advice on a subject that we don't know a fair amount about. Take that as a rare gem in this world full of amateur "experts"

They build some quonset huts in the valley here bigger than that. A row of big arches. here is the first I found on google http://www.americansteelspan.com/industrial.html

Brad

jasons,

There are a number of sites on the web where you can purchase and download software to calculate the beam size. Cost there is reasonable. (I don't know of any free sites.) You need to figure the load being put on the beam, based on the weight of the roof and supporting parts (the so-called "dead load") and then add to it any temporary additional weight or force it needs to carry from things such as wind or rain (the so-called "live load"). Typically the building codes will specify the required live load value for your area. This load is often quoted in pounds per square foot (psf), but the beam calculations may need it as pounds per foot of length or total pounds of load. You also have to decide if this load is uniformly spread along the entire length of the beam or is more concentrated in one area than another (such as for a non-rectangular building or one with some equipment on the roof in one area.

Like others have said, there are a lot of unknowns in your original post as well as your subsequent replies. Hopefully you can take the comments above and muddle through them to a final beam size. Then a supplier can tell you the cost. A beam of that length may pose transportation problems and would probably need to be supplied in two or three pieces that are bolted together on site. The supporting posts would be substantial, as would be the footings on which they sit.

Go as far as you can. Convert the gauge of the metal to thickness and then figure out the volume and from this calculate the weight. Or, contact a supplier and ask them the weight for a sheet of some specified or typical size. Come back with any specific portion you haven't understood and I suspect you will get an answer you need. As others have said, we are all donating our time on CR4. Also, we all are learning from each other.

--JMM

For a building that size your best bet is to do as was suggested previously, namely BUY FROM A MANUFACTURER!!!

A few that come to mind offhand are:

Gulf States Buildings

American

Butler

I have had personal experience with erection of buildings from all three. The will be more than happy to provide a quote for the engineering and materials. Gulf States will even contract a local (to you ) erector for you.

Another that I have not had any experience with is Morton. They have offices nationwide, and would probably be willing to talk with you.

Do a google search for steel buildings, there are many more out there.

DO NOT under any circumstance attempt to build that large a span on your own!!!! It is almost certain you will get someone killed!

hehe .. wow! Somebody didn't have their coffee this morning. "A site for information, not opinions"? Umm .. no. Both, actually. And much more.

Jasons .. welcome to CR4. But to lash out at people giving good advice (and good opinions) is not what we do here. First off, as has been said, you did not give nearly enough information in your question. A 100' span is a BIIIIIG span! The variables involved are tremendous. It reminds me of my Project Managers sending me a design request by simply stating "Design something this big for me, on this site". I reject those requests in a second and tell the lazy bums to go out and get me soil reports, local building codes, photographs from a couple dozen angles, preferred materials, sketches, allowable budgets, etc. The list goes on.

You could go to a university library and find the simplest beam calculation for a 100' span, provided you know what deflection is acceptable, and find a beam that will make that span. That is about all you could possibly get from our panel of experts on this site that hail from points all around this earth. And you could find a price for such a beam. But I suspect that price will not be relevant to what you actually need.

I too have issues with certain architects. Occasionally their "visions" are not practical, nor do-able. But nevertheless, they have a needed skill in an undertaking of this sort. This is not a wood shed that you're talking about.

If you ask again, with more information, and less attitude ... you may possibly get enough information in return that would allow you to get a reasonable cost estimate on certain components of your proposed structure. I did hear one particular suggestion that you may want to explore ... the arched quonset hut design sounds like it may work best for your application. If we only had more info ... maybe the people you've already offended would take the high road and help you some more. It is the Christmas Season, after all

First question:

What defines those 25'9" bays?

Don't you mean 100' long, spanning 25' 9''?

It would be a whole lot easier.

Assuming you have sufficient background about structural analysis/design, you need to do the following:

1. Draw a plan/layout of your proposed building.
2. Determine/decide how the structural framing system would look like and what/how the supports will be. Concrete column? Or steel column? Fixed? Or simple type? Also consider the effect to the foundation analysis/design.
3. Determine/decide (from applicable codes) your live load, from the type of occupancy. Also take into account the effects of wind load or earthquake forces, whichever give the critical effect, or both to be taken into consideration.
4. Determine/calculate dead loads that will be supported by each building frame. Add other dead loads to corresponding bay frame where/when applicable (i.e., wt. of walls)
5. Calculate resultant loads from a tributary area of beam span (100') by bay (25'-9") for the inside bay frames and half of that value for the end bay frames.
6. Based on above results draw FBD.

Now you can perform your structural analysis and design.

Hope the above answered you question.

WoW! I've been looking forward to reading all your remarks over the weekend. I never would have thought one little question would have created such a discussion. The first remark I received sort of reminded me of my mother. She always thinks the worst. In no way was I demeaning this site. I have had other discussions that were very interesting and very helpful. I think I'm to the point in this conversation that I don't even care about the answer I'm just enjoying the debate, however mixed in between everyones "opinions" there might just be a decent answer to my question. By the way I went to a metal building manufacturer before I started this discussion. I thought I would estimate my cost on a totally "weld-up" building which is generally not as expensive.

You got love some of these lame responses you get on this site sometimes. To think by some of these responses that you were just going to fabricate and build this building on your own without anyone's knowledge. I'd like to see you sneak in a 100' beam without being permitted. That's something no one would notice.

I did have a question similar to what Guest had. If you don't want to have any inner columns, then how will you have more than one bay?

My suggestion is to do a search on structural load charts. I've found in the past for wood and am pretty sure I've seen them for steel without having to pay for the information.

Well actually, a 40' beam is generally considered the maximum length that one would be able to truck in. Except under very special circumstances... and very high cost.

But that's neither here nor there.

Although referring to peoples' attempts to help, as "lame" ... probably not in the spirit of the season ... or helpful to the friendliness that is such a nice part of CR4

So I guess lecturing someone for asking a question 'is in the sprit of the season'? And I guess calling him a fool if he takes plans from the internet is 'helpful to the friendliness that is such a nice part of CR4'. Such insightful advise.

Sorry for taking your concentration off of calculating 'How much paper you'll need to carry 10 people in a paper airplane'. I think I will stick to referring to them as 'lame' responses.

Lighten up Sonave. No need for that here. This place is for learning and enjoyment. And just plain fun, too. We're brothers (and sisters).

I apologize for what you see as lecturing. Just trying to encourage civility, is all.

No need to apologize, the lecturing wasn't in reference to your comments.

I guessed I missed the intellectual stimulation derived by the majority of comments let alone accuracy in their advice. As far as fun and enjoyment, I've never found the need or desire to be part of the pack mentality, so forgive me if I don't find the humor when it is at the expense of putting someone else down.

Their would not be one beam 100'. A single slope building at 100' is not very common. My intentions are to have a gable roof with a span of 100' which makes the run 50' @ 2/12 pitch that would make a rafter 50' 8 9/32". Most flatbed trailers are 43'-48'. I don't think any states in the US require any permits for being less than 3' hanging over the trailer. As for the confusion on the bays. The building will be 100'x180'. I want all of the interior of the building to be free of columns. If you take the 100' as the span then you assume that the rafters are running perpendicular to the length of 180'. I know from previous recommendations from structural engineers that I can span a bay with a 10" c-perlin at least 30' with similar loads, so if you take the 180' length you can have 6 bay spacings of 30'. For estimating purposes I'm using 7 spaces @ 25' 8 9/16".

I didn't think any comment was lame just a little overdone.

You can span 100' using wooden 6"x 8" beams

This will hold up the roof and do anything you want it to do

Guest,

I think you got a "decimal point" off there. My tables say the span for 4-2x8's (which is the same as one 6x8) is 6'-1", when holding up a ceiling and roof on a 28' wide structure. Now, if you were meaning to use 6x8's to build a heavy-timber truss, then it might be possible.

--JMM