Metal Joists

Could you describe a bit more clearly what you want to do? I currently understand that you want to make trusses from angle and rebar? There are some elegant and cheap solutions using these materials. What is the final covering of the roof to be? Are they to be beams between posts or cantilevers? or part cantilever?

Thanks so much first off for even taking time to help. My shop was originally a 3 car garage that is 30' wide, by 40' deep with a 12' ceiling. There are some more additions to it now but my pad that I want to cover is in the front of the original shop. The main shop has block walls and a timber ceiling and roof, you know the "A" frame style. So the pad is what I want to cover now so to be able to work outside even in bad weather.

Damn I wish I knew how to draw in these messages!!!LOL,LOL

Any way what I want to do is a truss every 9', that what I was told to do by the folks who sold me the decking material. It's a heavy gauge material that looks like that style I've seen them pour concrete over for porches and the like. I measured the decking material and it is .035 thick and about 2 1/2' wide by 20' long.

What I am trying to do is put a truss at each end and the middle of the "A" frame so that I will still be able to get around without runing into anything. I have some 4" steel pipe that I was going to put the truss on.

Thanks again for helping folks

Damn I wish I knew how to draw in these messages!!!LOL,LOL

Sparky has recently "published" a very good tutorial on posting pictures:

http://cr4.globalspec.com/thread/15743/How-to-insert-Graphics-into-your-Post-to-make-it-more-readable-or-interesting

And there have been some good threads on CAD and drawing recently.

http://cr4.globalspec.com/thread/12126/Drawing

http://cr4.globalspec.com/thread/13483/CAD-Software

http://cr4.globalspec.com/thread/4248/3D-Cad-Software

A lot of the packages are very cheap or free. For your current project I would have thought that sketchup ( http://sketchup.google.com ) was ideal: the free version is more than adequate, and, it's incredibly quick to get up to speed.

Thanks Bill, I'm looking at it now. The only problem I'm having is it's over my head with some of the terminolgy. But thanks again at least I have something to go on and learn from. Oh yeah Bill, I see your from Clemson. So if I don't get this thing figured out I'll have to get you to drive up my Place in "Sugar Tit South Carolina". We are only 5 miles from the BMW plant.

I hate to suggest this ('cause it doesn't mean that someone else did it right and as an engineer, I just don't like to suggest such things), but find someone who will let you look at their building with joists/trusses similar to the length, load-carrying capacity (typically industrial building have a minimum of 100 psf/live load, and light commercial buildings have a minimum of forty psf live load capacity), of what you want and measure the angle iron, web iron, etc. Also, inspect the method of welding the things together.

Yes Bill that's what I have been doing it's just been real hard to get out these days as I'm still in recovery from a back problem I had. Thanks again

Chuck,

The smallest depth is 10" for a 20' span.
The span cannot exceed 24 times it's depth.
From your measurements of the decking it is 20 gauge.
I myself would add another joist between the two ends of the 20' decking.
The size of angle iron and rebar would depend on the weight you are putting on the joists. Don't forget the bridging, two rows for a 20' span.

Here are a couple links to help you.

http://www.quincyjoist.com/Catalog/KSeries3.pdf

http://www.wheelingcorrugating.com/WC-catalog/DeckProducts/index.htm

Chazl

Chazl thanks so very much for your reply as that's what I'm looking for. See I'm just extending my shop roof to cover the front cement pad so I can do more work outside with cover. The joists I want to make would be for the two bottoms and middle of the "^" shape as an end view. Then I was told that I could add perlins every 9' between the joist for support. The two what I'm calling bottom joist are the ones I want to be as small as possible because clearance for work, forklift and stuff of that nature. I'll run the decking from the center at the top to the "Bottom" joist with perlins in between the top joist and bottom joist. So the 20' span is from my shop roof out to a point in front of the shop. The shop is about 30' wide and I'm not sure of the angle or pitch I think is what they call it that the roof is on the shop but I will just match it of course. Thanks for the links,,,,,,,

Use "Hambro joist". You can find contacts on Google. Search "Hambro Joist". They do all the design and supply. Not sure about Installation. We generally use Forming contractor to install.

sounds like a good thought, Google here I come,,,,thanks,,,,

HMMMMM, I must admit you have lost me with the "ERW Tubes as perlins", please explain more as I do think it sounds like what I may need in the form of "Keep it simple"

Electric Resistance Welded or ERW tube/pipe, formed from cold-rolled sheet with a welded seam, and

http://www.cad-quest.com/support/post/glossary.aspx?sm=up1

for definition and example of roof purlins. Hope this helps, and cheers, Jim

Thanks Jim, I still don't understand what he meant by saying to use the tubes as perlins. I mean I know what perlins are as i was planning on using the old Z style between joist. He also said that thy would be corrosion free???

Sort of a modified post-and-beam construction I guess. As to ungalv. black iron being corrosion-free, perhaps on the inside, but w/o paint, the outside would rust. Dunno. Z-purlins are probably about as strong and likely lighter, so I'd say good choice. Make sure it's Hell for stout, don't want the next named storm to put it in your workshop! I appreciate your initiative. I'd love to do more stuff like that for myself, but here (FL west coast) you have to have an engineer's stamp on the plans and a licensed contractor to put new windows on the dang house! Money-grubbin' so-n-so's anyhow...grumble, grumble, gripe...

Thanks again and I know all about thoughs engineer and reals,,,,,,it kinda figures that most of them work for the goverenment doesn't it,,,,,,lol,,,, my family and I hope to visit your part of FL. this summer, or near you atleast. We want to go to the part with the white beaches and clear water.