steel distribution header for light gauge framing 1

[bjb]

I'm looking for the best way to attach a structural steel distribution angle to the top of a load bearing light gauge steel stud wall. The vertical leg of the angle is pointing downwards towards the floor, and can't be pointing up because roof trusses are extending over top of the wall. I would like to weld it, but my concern is that the fillet of the angle prohibits the vertical leg of the angle from being against the studs. Welding the horizontal leg to the top track is no problem. I am considering using a steel shim, but I wonder if there is a better way. half inch shims would be required becuase the angle is 3/8" thick, and the k dimension is 7/8".
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This is my crude sketch of the orientation of the header.
Thanks.

 

[jheidt2543]

Do you have access to the American Iron and Steel Institute's Cold Formed Steel Design Manual? They have a lot of information, codes and details regarding welding to light gauge steel framing.

 

[bjb]

no, unfortunately I do not have access to this manual

 

[haynewp]

Why don't you use a bent plate instead of an angle?

 

[JCWilson]

Am I correct in assuming that you have limited space to play with where only the thickness of an angle leg will fit between the top of wall and the lower chord of the roof joists?

 

[bjb]

haynewp, I still have the problem with the bend radius of the plate keeping the vertical leg off the stud.

JC, you are correct. If there was more room, I would have used a tube.

I have seen drawings for several other projects where this detail has been used, but unfortunately I don't think they were drawn correctly because they show the vertical and horizontal leg of the angle flush with the stud and the top track. The distribution angle was just "cartooned in there". Unless I hear of a better way, I am going to specify that a shim be shop welded to the vertical leg of the angle so I can weld both the vertical and horizontal legs of the angle to the light gauge framing.

 

[jheidt2543]

Another thought might be to just use a flat 3/8" (or whatever thickness you comupte) plate. All you are really trying to do is distribute the joist load to the steel studs and the top lightgage track is not heavy enough. The plate can be either welded or screwed to the track with self-drilling screws.

 

[Neilmo]

bjb,

How about grinding away the top of the stud(s)to clear the fillet radius of the angle, thereby allowing the downward pointing leg of the angle to lay against the stud, without the need for a packing plate.

Regards,
Neilmo

 

[jheidt2543]

Neilmo,

Your suggestion is way too labor intensive and expensive. Actually, the times I have seen the angle used, the horizontal leg was just tack welded in place to the top lightgage track and the space between the stud and the down leg of the angle ignored. Once the roof weight from above is in place the angle isn't going anywhere. The angle is just to distribute the vertical loads to the studs. But, if the space is a concern, use a plate instead.

 

[lesmcg]

Your angle seems very heavy. Have you contacted the Light Gage Steel Engineers Association? Don Allan is their ED. They have a number of standard sections and deemed to comply provisions I believe. Here in Aust I would probably be using a 2 or 3 mm thick angle but of course depends on your load and span. We use higher stress grades than you guys. Tek screwing to the studs gives enough restraint normally.
Les McGrath
National President
National Association of Steel House Framing(Australia)

 

[Neilmo]

jheidt2543,

It would obviously depend on how many studs there are, but point taken.

Regards,
Neilmo

 

[bjb]

My spans are large, and my loads are heavy. This is a critical facility (part of a fire station) in upstate New York, where the snow loads are very heavy. My uniform snow load is 55 psf, and the drifting and nonuniform snow loads just make things worse. I could make an angle thinner than 3/8" work, but for architectural reasons 3/8" works nice to get the desired truss bearing elevation. My wind uplift is significant, and so are my seismic forces, believe it or not. I mostly want a good connection between the vertical leg and the studs so I get a good load to resist wind uplift, but I guess I could accomplish this with selfdrilling screws between the horizontal leg and the top track. I will contact the Light Gauge Steel Engineers Association to get their advise. Thanks for everyones input.

 

[unclesyd]

A little late but,
Here is a web site that I ran across that might help. Looks like some pretty good information.

http://www.ssma.com/technical_library.htm