Steel Beam Questions

[DawgPaw]

I’m thinking about about steel beams instead of engineered wood. I will have room for something around a 24x36 shop. I want to have a steep pitched roof and finish the second floor.

Any estimates on the beam size to span the 24’? Probably 2 of them 12’ apart. Do I set them on lumber or steel columns?

I’m sure I need to get a professional opinion. Any idea how to find somebody who would run the numbers for a shop?

And would it be possible to run a hoist on a trolly? There are times that on would be handy for me.

 

[Want2race]

Need to know what’s on top of the beam. What’s the loan on the floor above etc.

It’s easily possible but spec is a going to be pretty big beam.

 

[DawgPaw]

It will be storage and an office area. I hope to finish it.

 

[MrSurly]

When I was anticipating a loft and utilizing some readily-available I -beams, NObody here would even discuss it, “hire an engineer” was the only answer.
So, good luck!
I researched as well as I could, the span tables to at least determine that I would have LOTS of over-build in mine such that I know that at a *minimum* it will support ten times what I could ever put up there. That was the only way I was comfortable.
I used heavy steel columns on the clear span side (29’) and the other side is attached to the post frame timbers *and* supported with 4X4s to the slab as well.
Either make sure to overbuild it OR have it engineered.
I paid to have my entire building engineered but not the loft that I added later.



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[gearhead1]

Engineers can’t consult without having passed the PE exam. This has nothing to do with how everyone is ‘sue happy’ nowadays. An engineer is liable due to the technical training one received so most are going to refrain from saying anything.

My shop spans 36’ with attic trusses, so I have a big second floor. Have you considered attic trusses?

 

[Bigblockyeti]

You need to know deflection tolerance; L300, L360, L480, etc. and you need to know the load 10psf - 50psf. If there's a "room" above, it will be considered live load.

 

[DawgPaw]

Yeah I did a lot of searching and didn’t get much. I was just trying to get some rough numbers, but oh well. I’ll probably hire an engineer once I am ready and find someone. Anybody at least have an idea what they charge?

 

[MrSurly]

Mine is a pole barn “post frame” style that I drew up using the typical building methods in my area. I sent my drawings to a P.E. who specializes in this type of building. He drew proper plans and details specific to my plans with lots of doors, a big porch, eaves and soffits plus the city’s wind and other requirements, soil type etc, including a full fastener schedule and BoM. His specs included much beefier materials. My material costs went up but my peace of mind went up much more. It was an expense I honestly would NOT have elected on my own but the city required it, and I don’t regret it at all.
His charge was under a grand.


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[tarmy]

Steel adds a fair amount of cost to the build. I looked into it for my 32’ clear span with living over it. Ended up with wood trusses that have a 200 lbs. sq ft live load for loft and hoist built in.

The wood trusses are standard installation, albeit huge size and shipping issue.

Have the structural advise you about the design and installation costs...not just the buying part...framing crews have different skill sets...steel is not common where my build was.

 

[s14kev]

We just installed two steel beams to span a 28ft basement garage space. They spec'd out W88 beams. 88 pounds per foot. That's 2500 pounds per beam. Probably much larger than you would need for a shop since you are not supporting 2 stories above.

 

[My Old Tools]

Red iron building is the easiest way to get there. The builder can spec the beams you need. I requested a 1 ton overhead hoist beam in mine, along with a second floor storage loft that would hold fairly heavy machines. Doing it over
I would require bridging between the floor joists. Otherwise I'm happy with it.

 

[ddawg16]

As you have figured out from above, no one wants to 'help design'....many factors....one of them being we don't want to lead you down the wrong road.

As a metric......consider this....I have a 20's wide garage with a 7"x16" PSL beam across the 20's span. I have a second floor above...10 lbs dead load, 40 lbs/sq ft live load. I have 2x8 floor joists anchored to the beam. Very stiff. I think the beam cost me about $200.

Consider a steel beam is going to run in order of $2/lb. I'm willing to bet cost alone will change your mind.

Also consider it's going to be more difficult to attach to that beam than an engineered beam like a PSL....nails won't work.

Because of the questions you're asking....you should really be having a chat with an engineer on this one.

Be ready to fork out the $$ for a design....no city is going to approve it without a set of wet stamped drawings.

 

[DawgPaw]

Interestingly Garrett Hack has exactly what I’m talking about although he used salvaged beams. I’ll get an engineer to go over the options though.

https://www.finewoodworking.com/2008/11/19/video-tour-of-garrett-hacks-vermont-workshop

 

[kbs2244]

Find your local steel supplier.
That is where you will be buying the beams.
They will have an engineer on their staff that can do the math and provide the legal paperwork.

 

[WNYflyer]

For a 24' span and a 12' wide contributory width loading it and assumed 10 psf floor dead load and a 40 psf floor live load you would be looking at W12x16 when holding the live load deflection to L/240 = 1.20" or a W12x22 when holding the live load deflection to L/360 = 0.80". That it assuming steel beams of ASTM A992 (FY=50,000 psi) material.

All of the above is assuming the top flange of the beam is basically laterally braced continuously by some system which in the case of basically all timber construction would typically be a continuous floor diaphragm of 2x joists and plywood floor. Correctly determining the assumed laterally un-braced length of a beams compression flange, in this case the top flange, is of the utmost importance when sizing any type of beam. The assumption of that un-braced length can have a huge affect on the size of the beam and therefore its cost.

The above should get you in the ball park size wise. I would follow kbs2244 advice above and contact a local steel supplier about designing, supplying and certifying the design.

 

[gearhead1]

When I did my shop, I think they charged me $300 for a drawing and the concrete calculations. The engineer (PE) the truss company hired did the calculations for the trusses. The county inspectors are usually not engineers, they just ensure the structure meets code and meets the engineered (PE stamped) plan.

I’m a mechanical, but don’t have a PE so I could not stamp the drawings and I don’t know how they do the concrete calculations, I never had that in school. So I paid to ensure it was engineered correctly.

Now when it comes to a hoist beam for doing what I want to do, I can do that. Most of the structural beams are made from A36 which is a 36,000psi yield strength steel. You draw the free body diagram with the load, then the moment and shear diagrams. Beams usually fail in bending so you take the highest moment and use that to calculate the stress in the beam using the formula of M*c / I. M is the max moment, c the distance from the neutral axis to the outer most fiber, and I is the moment of inertia. You take the yield strength of the material and divide by the calculated stress to determine the safety factor. Overhead beams should use a safety factor of 5. If you have less than that, then you have to increase the size of the beam and re-run it. Then you have to calculate the load on the supporting posts. First determine the slenderness ratio and if it is a long column or short column. Euler’s formula if it is a long column and Johnson’s formula if it is a short column.

But what loads you use on a structure with multiple beams I have no idea. I assume the wind load of the roof divided by the area, then spread that over the number of beams? That’s where a Civil engineer is needed who is specifically trained to do that. The other thing is the failure mode can be deflection. So what deflection is acceptable, I have no idea.

I’m not one to ‘over-engineer’, or over think stuff, I do a fair amount of just put it together myself. But when it comes to load calculations on structures, I want that to be by the book 100% right......so I paid a civil engineer. It’s been through a couple hurricanes. I have complete peace of mind.

 

[Farmall450]

Steel adds a fair amount of cost to the build. I looked into it for my 32’ clear span with living over it. Ended up with wood trusses that have a 200 lbs. sq ft live load for loft and hoist built in.

The wood trusses are standard installation, albeit huge size and shipping issue.

Have the structural advise you about the design and installation costs...not just the buying part...framing crews have different skill sets...steel is not common where my build was.

Yes, it's timely to marry steel to wood.

 

[DawgPaw]

I appreciate all of the advice. Looking at prices it still looks feasible which is what I was looking for right now.

 

[metalmagpie]

When you add structural steel to a project, permitting and inspection get enormously more complicated.

 

[bob15]

You need to know deflection tolerance; L300, L360, L480, etc. and you need to know the load 10psf - 50psf. If there's a "room" above, it will be considered live load.

Actually the room above would be considered a "dead load": Walls, flooring, roof, ceiling, permanent structures in the room (built-in cabinets or shelving), etc

Live load would be: people, furniture, appliances, movable items

Environmental loads: snow, wind, rain, etc

 

[Bigblockyeti]

Actually the room above would be considered a "dead load": Walls, flooring, roof, ceiling, permanent structures in the room (built-in cabinets or shelving), etc

Live load would be: people, furniture, appliances, movable items

Environmental loads: snow, wind, rain, etc

Post #3: "It will be storage and an office area. I hope to finish it."

 

[firebirdparts]

Here, if I went to a steel shop and told them what I wanted, they might do a rough sizing for you with a simple span table. They might. If that's all you want and you want it free.

 

[GMCGarage]

For a 24' span and a 12' wide contributory width loading it and assumed 10 psf floor dead load and a 40 psf floor live load you would be looking at W12x16 when holding the live load deflection to L/240 = 1.20" or a W12x22 when holding the live load deflection to L/360 = 0.80". That it assuming steel beams of ASTM A992 (FY=50,000 psi) material.

All of the above is assuming the top flange of the beam is basically laterally braced continuously by some system which in the case of basically all timber construction would typically be a continuous floor diaphragm of 2x joists and plywood floor. Correctly determining the assumed laterally un-braced length of a beams compression flange, in this case the top flange, is of the utmost importance when sizing any type of beam. The assumption of that un-braced length can have a huge affect on the size of the beam and therefore its cost.

The above should get you in the ball park size wise. I would follow kbs2244 advice above and contact a local steel supplier about designing, supplying and certifying the design.

Going a bit further and adding a 1000lb hoist load at the center I come up with a 16x36. Also limited deflection to L/600 for the trolly to work correctly. Fully unbraced too unless you have a floor plan you can supply.

 

[cadunkle]

Have a look at https://webstructural.com/beam-designer.html

I've done a few steel beams and used their tools for quick sizing, then verified on paper doing all calcs myself. Inspectors didn't question my calcs or install, all was approved with no issue. This isn't rocket surgery, anyone can size a beam various material if you're inclined do some research. Used to be Webstructural gave you the full detailed report for free for simple beam calcs and loads, but now they charge a subscription model. If their subscription model allows you to just sign up for one month it would be worth $19 to me to narrow down and do quick calculations for different size/shape/material beams and loads, vs doing it all by hand.

 

[ddurrett896]

I spanned 22' with a double 24" LVL that supports like 11 trusses.

I contemplated steel to reduce the 24" drop, but no supplier could tell me what I needed. Tried calling a couple engineers with no luck.

 

[bob15]

Post #3: "It will be storage and an office area. I hope to finish it."

If it is a finished office with carpet, ceiling and finished walls and such, those are dead weight loads. I agree the storage is live, but the finished office is dead weight.

 

[dcg9381]

Engineers can’t consult without having passed the PE exam. This has nothing to do with how everyone is ‘sue happy’ nowadays. An engineer is liable due to the technical training one received so most are going to refrain from saying anything.
My shop spans 36’ with attic trusses, so I have a big second floor. Have you considered attic trusses?

Agree, but I believe most of them are using software and not exactly doing manual calculations any more. I have used the calculators for LVLs - looks like someone found one for steel.

I assume it's like wood - if you're buying enough of it, they'll throw an engineer at you (free or low cost) to help you. For a one-off, you're probably going to need to use a calc.

 

[aventino68]

There's a very very basic calc using span in feet/12 x 0.5 which gives you a ballpark and isn't miles off for distances under 30 ft. We have a 41 ft span on our house design and that would be around a 410x56 H beam (16") while engineers are still doing calcs while I got 20.5" using the above.

 

[brownbagg]

hope you got alot of money, steel not cheap, single small beams are over $300

 

[cvairwerks]

Run it thru Mueller or Rhino or one of the other big name metal building guys. The additional engineering doesn’t add much to that side of the building cost. Guys like that buy materials in multiple rail car loads and usually can beat the local yards on price for all the materials. Steel packages assure that the building will (99.5% of the time) go together correctly.

 

[scottydosnntkno]

it depends on what you consider easy and what you value more, time or money.

using all engineered wood, you can do a LOT of things with Ijoists, high-strength ijoists, or step up to floor trusses that can clearspan 20-25-30-35' with no problems.

my garages are 35' deep, and use 20" deep floor trusses to clearspan bedrooms and bonus rooms above them. by the time you spec a beam, columns, and joists on top to span the same distance, you'll be at the same depth. but then you have all the connection, footer and locating issues to deal with. my joists bear on top of normal 2x6 walls, just built a little shorter vs. the house floor that has 11-7/8 i joists.

if floor depth is a big concern for height reasons, a GOOD truss company can design your a floor and roof system where you tie the trusses to the floor trusses with a specific nailing pattern for increased loads and decreased depth.

but, steel does have its place and its incredibly strong compared to wood. our house has 13 beams of various size up to W32x210 (yes, 210 PER FOOT) in one spot. Some posters have said steel can be $2/lb, but in our case we were just shy of $1/lb and built two years ago in michigan. our architect did everything possible to use engineered wood, but with some high loads (that big beam has a 28,000lb point load in the middle of its 20' span) you have to use steel.

 

[bb29510]

if you go steel beam. think about gantry crane, or at least a trolley to ride the beam

 

[readhead]

I’m guessing that the building is done since this is a four year old thread.