Joe, I have an electrical contractor that is using channel for bracing flag poled service risers. He is cutting the channel on both sides so he can get a bend to meet his needs. I'm not comfortable with the cutting and bending as I think the strength of the channel is in the design with the sides intact. Can you run this through for comment by the contractor's network and/or give me any code reference that may apply to this type of installation?
I've installed a number of "mast kits," and I am not really impressed with the design of the factory made solution. I don't think the NEC discusses this issue, so i took a look at our local utility's specs:
"Periscope structures projecting over 30" above the roof must be braced....Bracing, when required, shall consist of two galvanised steel members installed at approximately 90 degree spread. Minimum size brace shall be 1 1/4 x 1 1/4 x 1/8" galvanised steel angle. Periscope bracing shall be anchored through the sub-roof with minimum 3/8" galvanised carraige bolts." The accompanying artwork also specifies the bracing to be attached 10" below the weatherhead.
Ironically, the "mast kits" that I've been using rely upon 3/4 RMC for bracing members, and anchor to the roof with lag bolts (that might be 3/8").
Off the cuff, I would guess that this man's solution is as strong as the commercially prepared kit. It is certainly securely anchored to the mast with those multiple mineralacs. It is also quite a bit more expensive than the commercial arrangement I've been using.
Re: Question on Flagpole Risers#119811 01/27/0508:55 PM01/27/0508:55 PM