Welding to steel joists

[dbnerds]

I remember a rule of thumb:
Don't weld across a steel joist chord. All welds should be parallel to the length of the joist.

I can't remember how/where I picked up this nugget of knowledge. Can anybody point me in the direction of what authority this is under? (books, code, text, anything)

Thanks

 

[DaveAtkins]

I have heard the same rule of thumb, but don't know where it came from.

It makes sense though--joist chords can be thin, and welding across them could weaken them.

DaveAtkins