Point Loads on Steel Bar Joists

[hoopvols]

What is the maximum distance a point load should be placed from the actual panel point of a joist and how much can that load be before supplemental struts need to be added? For example, is a load of 80 lbs 12" from a panel point to much without adding a strut if the joist has adequate shear and moment capacity?

 

[spats]

The rule I use (don't ask me to justify it... you can't) is that 150 pounds is the max load you can add to a joist, not at a panel point, without adding a strut. The 150 pound max point load also cannot be more than 6" from a panel point, unless a strut is added.

 

[jike]

I generally don't want to be more than 6" beyond a panel point for "K" or "LH" series, perhaps 12" for "DLH" series.

The amount of load that I allow is dependent upon the size of the joist and anticipated size of chord. Chords may vary from 1 x 1 and 2 x 2 for "K" series; 2 x 2 to 4 x 4 for "LH" series and 4 x 4 to 6 x 6 for "DLH" series.

Some older joists may have "hat sections" or "rods". I do not allow any concentrated loads to be hung from rods.

 

[UcfSE]

6" is typically what I see and assume, though as others have said, it varies and may be difficult to justify. That said, I have a set of shop drawings from a joist manufacturer that show this detail with a maximum distance of 3" from the panel point.