# Mast support question: CEC-2009



## stuiec (Sep 25, 2010)

I'm pretty sure that it is in the code that you must secure the mast supports through a minimum 1.5" peice of building structure. Check it out. I have not had trouble with movement when using the supports you mentioned, though I have only used them to secure 2" on shorter runs.


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## stuiec (Sep 25, 2010)

Check out 6-112 (4) and (6)

(4) Where service masts are used, they shall be of metal and assembled from components suitable for mast use.

(6) Bolts shall be used for securing the support at the point of attachment, and if attached to wooden structural members, the latter shall be not less than 38 mm in any dimension.


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## CanadianBrad (Feb 9, 2012)

Definitely appreciate the code references, reading that over now. Here's the part I can't figure out. Each of our 3 struts was supported by 65mm lag bolts, through the 1/4" outer sheathing, and fairly deep into the 2x8 framing. The second piece of strut, between the first piece and the pipe, was in place to stand off the pipe to make it past the roof lip. 3 points of contact to the pipe, both held in place by 2 lag bolts, sunk through the outer sheathing and into the framing. Now, there are 2 points of contact between the conduit and the structure, with 3/8" threaded rod and washers/nuts, supported by the outer sheathing and 1.5" thick scrap lumber. Our original unistrut setup provided as much(or probably more) support against forces pushing the mast away from the building, and certainly far more lateral support. But, somehow, in the inspector's eyes, this is superior.

Regarding code rule 6-112(6), the only thing that I can see being less than 38mm is the outer sheathing, which is part of the securing structure in both methods, and certainly doesn't qualify as a structural member. Before, we were attached to structural members that were 1.5" by 7.5", and now, we're attached to a block of scrap measuring 1.5" thick, which is not part of the supporting structure.

I appreciate the input, though. I really wish I had some pictures to help me illustrate the point.


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