sizing I-beam for shed

[bdog]

I have a 30x40 metal building.It is 40 feet long in the direction that the peak of the roof runs. I am wanting to add on to the side of it a lean to / shed. Basically a roof with a back and side wall and open front to store implements or whatever under out of the weather.

I have googled and searched and can not find any tables for beam size requirements. I am trying to figure out what size of beams I will need to support the structure.

I was thinking three beams 20 feet apart and a width of the shed of 24'. The beams would then have purlins welded to the top of them to screw the R-panels to.

 

[Shield Arc]

Will this help? If not if you can give me an idea of what kind of loads you'll have I can look it up.
This chart is for the beam being uniformly loaded, if you want point loaded, divide the number in half.

 

[bdog]

Thanks for the reply.

The chart is probably what I need but I am not sure I know how to read it. What are Kips and how do I determine how many I need to be able to support? What is the standard required for a roof?


I am in Texas so we don't get major snow. I don't ever plan on putting anything on the roof. I just need the beam to be able to support itself, 8" C purlins, and 26 gauge R panels. There will be three beams spaced 20 feet apart and the span is 24 feet. (My structure will be 24 feet wide and 40 feet deep). I plan on putting the 8" C purlins running in the 40' direction spaced 4 feet apart.

 

[Shield Arc]

A kip is 1,000. pounds.
You'll have to figure out all the weight that is going on the roof, plus snow load. Then figure out how many posts / span.
I scanned another chart with smaller beams for you.

 

[sjames]

1kips = 1000lbs.

 

[flusher]

I have a 30x40 metal building.It is 40 feet long in the direction that the peak of the roof runs. I am wanting to add on to the side of it a lean to / shed. Basically a roof with a back and side wall and open front to store implements or whatever under out of the weather.

I have googled and searched and can not find any tables for beam size requirements. I am trying to figure out what size of beams I will need to support the structure.

I was thinking three beams 20 feet apart and a width of the shed of 24'. The beams would then have purlins welded to the top of them to screw the R-panels to.

I'd go with K-series open web steel joists--like you see in Walmart stores--to support your roof. A lot less weight to lift than with steel I-beams.

 

[sjames]

Shield Arc,

Is the second chart you posted from the ASD or the LRFD tables?

As i understand it, LRFD uses different factors when combining load. You would need to multiply you live and dead loads by different factors to arrive at the ultimate load. Without doing that you could be in the plastic range for the beam but be under the value listed in the tables.

If its an ASD chart I believe you can just add your live and dead loads together and consult the table to keep in the elastic range.

disclaimer: I'm not an engineer, my understanding of ASD and LRFD my be flawed.

 

[Shield Arc]

Boy you got me, I'm not an engineer either! I've only been on one train in my life.:laughing:

Scanned from Manual of Steel Construction Allowable Stress Design?

 

[sjames]

OK, ASD it is. :thumbsup:

Allowable Stress Design (ASD)
Load and Resistance Factor Design (LRFD)

 

[IXLR8]

bdog- I had a similar issue, I ended up hiring an engineer to design my loft with steel beam supports, cost me $350. Worth it to me not to have any questions and to have a plan to work from.