Steel Angle Joist Ledger Capacity 1

[INPE]

Could someone point me to a procedure for calculating the capacity of the outstanding leg of a continuous joist ledger? This would be similar to the capacity of a beam flange with a concentrated load.

 

[tincan]

Treat the outstanding leg as a cantilever plate with edge or point loading. Distribute the point load on a 1:1 to the attached ledger angle.

 

[SlideRuleEra]

One approach would be similar to the approach I suggested in thread507-103146
Treat the outstanding leg as a cantilever beam. Take a look at a unit length measured along the he angle, perhaps one foot. Apply the load over this distance to the cantilevered outstanding leg of the same "width". Compute shear & moment, determine the moment of inertia and section modulus of the outstanding leg, do the math and you have an approximation of the stresses.

 

[stanfea]

The above posts are the way to go. I assume by continuous joist ledger you mean an angle bolted to the wall which is continuous and has a joist on it every 4' or so. First off ignore all effects of continuity! Provide a full strength connection below every joist, otherwise the angle will be quite large depending on the loading.

The width of the angle which resists the loading is also a bit of a guess unless you are using FEA. I would keep the width fairly conservative (meaning a thicker angle) to be on the safe side. The cost difference between a 1/4" and a 3/8" angle for example is nominal. The connection to the wall or support is another serious and most important consideration. If your anchor bolts are say in the middle of the vertical leg of the angle then the applied force in the bolt can become quite large. Keep the bolts up as high as possible and the vertical leg longer and thicker. L3x5 and L4x6 are not uncommon. Thicknesses of 3/8", 1/2" and even thicker are also not uncommon. Good luck and remember failures are typically in the details...

Stano