# Steel/conventional wood hybrid construction



## txgencon (Jan 4, 2011)

I'm wanting to build a shop building for my business and want it to be a sort of steel/wood hybrid. The only steel components would be the wall columns and rafters. I want to fasten 2x4 blocks to the steel and use 2x6 rafters on 19.2" centers to support a 3/4" OSB deck and laminated asphalt shingle roof (4/12 pitch). The end walls, gables and side walls will also be conventional 2x6 wood framed with Hardie exterior siding. However, the steel suppliers I've talked to don't want to talk to me once they find out I don't want a complate package. My other alternative is trusses but I prefer the openness of the steel-supported roof.


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## knucklehead (Mar 2, 2009)

I have done quite a few jobs similar to that. With wood at least on the front half of the building. I would tell you to keep trying to find someone who will work with you on the thing


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## GettingBy (Aug 19, 2010)

The Modulus of Elasticity, MOE, for steel is 18x that of wood. This might be more relevant for the horizontal members. 
The MOE for most wood used in building varies between 0.8 and 2.2 million PSI.

For vertical members, start with
http://www.engineeringtoolbox.com/load-steel-pipe-columns-d_1348.html

You'll need to know the density of OSB and asphalt shingles in order to calculate the dead load. Figure 35# per cu. ft. for wood.


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## Joasis (Mar 28, 2006)

As the resident steel guy, let me give you a possible plan. One of my suppliers would be happy to sell you a steel frame package and then you can finish it to suit your own style. 

I can barely make out your print, so let me give you a general size. 

My supplier, Longreach Steel, Tecumseh, Oklahoma, 800 256 3237, can build you say a 30 wide by 40 long (or any size you want) and a pre-engineered building of this type would come with 3 inch square tube wall columns x 3/16 wall thickness to weld down to plates set in the slab or footing. The columns would be spaced 10 feet on center, and then an engineered truss would be welded across the columns. The trusses would be 2 or 3 on 12, depending on spec, and you would be able to have them, or you could do it in the field, attach purlin clips to space purlins, either steel or wood, on whatever center you desire. 

Using 3 inch columns for the walls would allow you to stud the walls between each column as a standard wall, and then finish to suit.

You would then have the best of both worlds. If you call Longreach, ask for Mark, and tell him Jay said to call, he will hook you up.

By the way, a complete steel package is less then $5 a foot including the exterior, and then you could frame out and finish the interior as an option. good luck.


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## txgencon (Jan 4, 2011)

I'm trying to stay away from the space encroachment trusses would have. I just want the steel superstructure for the interior of the building (with the wood framed end walls). I could use metal purlins to support the decking but I think using wood would make creating the gable end overhangs easier. Either way, the decking material would have to be turned 90 degrees to the way one normally installs roof decking. 

The steel suppliers I have talked to have a maximum pitch of 4:12. With 10 foot sidewalls, the maximum height at the center of the building would be 16.6 feet. Using trusses would limit the center height to the sidewall height (wouldn't it?).


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## Joasis (Mar 28, 2006)

Call another of my suppliers, Taylor Steel, in Chickasha, Oklahoma, 405 222 0751. and fax them drawings on what you want, keeping in mind you are after what we call a "clear span" design. You are not limited by pitch, or span factors for what you want, only what you want to spend. 

If you are not looking to have a center height greater then the actual wall height, then my original suggestion would be cost effective. the clear span style will cost you quite a bit more, and of course, is more involved since you will be doing piers and anchor bolts, as well as considering column reaction forces as well as loading.


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## txgencon (Jan 4, 2011)

Thanks. I'll contact them after I've added much more detail to my drawings. Chickasa is not all that far from where I'll be building. I picked up a midi excavator in Chickasa several months ago. My vet has a place not too far from me and he built a "standard" 40' x 60' steel building (pretty plain with 1:12 pitch roof). He loves the building but the guys he had build it did a really poor job on the foundation. Heck, it's not much more than what goes for flatwork in my book. I plan to have a foundation with piers and beams designed for however I decide to build the building. I realize that there are concentrated point loads much different than if I went with a conventional wood structure. I want my building designed to support not only what I've mentioned (decking, asphalt shingles, etc.) but a finished ceiling over spray foam insulation. Now that I think about it, I want to plan for a complete finish-out of the interior to include wrapping the beams to the point where the inside might look like a church sanctuary.


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## GettingBy (Aug 19, 2010)

If you don't want a truss structure can you stand gusset plates or struts at the intersections? 
Sounds like "no" if you want to wrap the beams.


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## txgencon (Jan 4, 2011)

Thanks to joasis. I've been working with Scott at Taylor Steel and he has come up with what I need. Well, almost. It seems I screwed up and said I wanted a 12' height. In steel building terms, that is the outside dimension and will yield only 10'-7 3/4" minimum inside height. Once he revises his estimate, I'll be good to go. Thanks again.


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## txgencon (Jan 4, 2011)

When the rafter columns are tapered, is the specified pitch that of the top flange?


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## Joasis (Mar 28, 2006)

Depends on the specific frame design....ask Scott and he will give you the variables.


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## txgencon (Jan 4, 2011)

I figure I'm just going to have to wait until I get them up and then match the adjacent stick-build to it. I guess even if I had a very detailed drawing of the steel, it would be unlikely to match it perfectly.


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