4" by 4 " angle 1/4 "

i have welded an angle to 16 ga. metal studs to support the end of a lightweight truss. is there a difference in the strength of the support relative to the orientation of the angle? trusses weigh 45 lbs. angle is welded twice per stud ( top/bottom ) at 12" intervals.

 

[jheidt2543]

Since the angle has equal legs the sort answer is no, BUT:

1. Welding the angle to the side of the studs induces excentric loading to the stud. You have to look at the condition of the stud: its length, is it braced at the top?, stud gage etc.

2. Welding to steel studs is an art, it is very easy to burn right through and leave no support. So, not only do you have to calculate the loading to correctly size the weld, it has to be performed in the field correctly.

3. The best detail is if you can put the angle on top of the studs, then the load is transfered to the stud vertically. That is not always possible, especially if the truss bearing has to slope along the wall.

Just some things to consider.

 

[Trussdoc]

You say that the trusses weigh 45 pounds. However, you should consider what they support as well, unless they are purely decorative.

 

thanks for reply...jheidt...trussdoc. does the orientation of the angle ( seat up or seat down ) make a difference in the amount of weight the angle can carry? does it deflect the same amount loaded one way or the other?

 

[haynewp]

Isn't L4x4x1/4 kind of large to be welding to 16 ga studs?

 

[sven]

The angle has different strengths depending on its orientation and load direction. In general, it is strongest with a flat top and one leg vertically down, when loaded vertically downwards.

Deflection will be the same whether the orientation is leg up or leg down.

Hope this helps.

 

thanks haynewp and sven...i was following detail by using L4X4...i thought it was large also...however, my installers put it in leg up, seat down instead of leg down seat up...

 

[jheidt2543]

I can't see that the leg up or leg down makes any difference structurally, if the applied load is parrallel to the leg. It may make a difference esthetically, if they are trying to hide the leg above a ceiling etc.

Again, I go back to the real "weak" point of the system which is the excentrically loaded welded connection to the steel studs. It is the same condition with leg up or leg down, but the key is a structurally sound weld.

 

hey jheidt 2543...thanks again...awesome web site...appreciate the info

 

[austim]

HI wldr.

Some authorities will tell you that there IS a structural difference between putting the vertical leg up and putting it downwards (as Sven has said previously).

There is a basic problem of local plate buckling if the maximum compression is at the toe of the vertical leg.

The Australian code (which is pretty hot on most aspects of buckling) specifies a reduced moment capacity for any plate element of a rolled steel section restrained at one edge and with maximum compression at the opposite edge which has b/t > 9 (ie outstand/thickness, which is 15 for your angle). If the steel is anything better than basic mild steel, the restriction is more severe.

If you have any doubt, ask yourself what would happen if your section was only 1/8 or 1/16 inch thick (or try a simple cardboard scale model - that will demonstrate the basic problem).