# how do you anchor conduit or masts to a structure?



## Chris Kennedy (Nov 19, 2007)

Depends on the type of structure. I never use 3/16 toggle bolts.:no:


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## erics37 (May 7, 2009)

I don't think I've ever put up a service mast on any type of stone. Every commercial service I've done has been underground.

Most resi siding here is plywood or Hardi-plank or something like that.

And in most cases our utility won't let us put up overhead services unless it's directly replacing an old one.

If it's going inside the wall I usually just screw it into the meter hub and let the wall framing and roof sheathing keep it in place, plus a guy kit if the mast is tall enough.

If it's going outside the wall through the eave and/or soffit then I either anchor it directly to the siding either with straps and long stainless screws or on some occasions, with some small chunks of stainless kindorf strut and straps. Kind of S.O.P. around here.


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## Mr Rewire (Jan 15, 2011)




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## electricalwiz (Mar 12, 2011)

for brick I use double expansion 
cinder block would be toggle bolt (1/4")
stone or concrete would be drop in
siding I would have to hit the top plate with a twp ear strap before it goes through the roof


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## walkerj (May 13, 2007)

Chris Kennedy said:


> Depends on the type of structure. I never use 3/16 toggle bolts.:no:


Man I miss Al.

Sent from your mom's iPhone. She says hi.


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## 220/221 (Sep 25, 2007)

A service on an eave side gets a mast brace that spans the rafter tails and pushes back on the mast. 3/4" IMC, drilled thru the tails or secured by offset brackets. If the 2" IMC mast is under 36" from the brace, it is all that's required.

The best pic I have is the worst example of workmanship as the brace crosses the Jbox :jester:. Generally the mast is in a different section than the Jbox(if there is one).










On the gable end it usually gets unistrut, thru bolted, thru a framing mamber.










Sometimes I have to get creative. This was flat roof and the eaves didn't have perpendicular framing so I cut a hand hole to get some nuts on the bolts, then screwed a blank cover over the hole. I felt the minnies were kind of wimpy so I used two of them.






















Once in a while I have to resort to tearing up the interior just a bit. I will drill thru the top plate(s) and use a carriage bolt pushed in from the inside.. The carriage head gets stuck in the lumber and the head gets sucked into the drywall making for a clean and simple patch.




When using conduit straps of *any* kind, we are required to use min 3/8" *thru bolts* of some kind. It has to go thru some framing member or the block/brick,concrete. Sometimes it's bolts, sometimes it's allthread.


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## SparkYZ (Jan 20, 2010)

Out here in So California, almost all the houses we run into are wood framing. Los Angeles Water and Power and Edison have similar requirements, 3/8'' lag bolts into framing members, securing unistrut to the wall, two pieces minimum 24'' apart.


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## macmikeman (Jan 23, 2007)

Ok so the pictures with the brick and cmu houses are not exactly the kind that your average movie stars are going to live in, but I sure hate to see sissy bar, er, um I mean unistrut used on a dwelling exterior walls. Outside the 7-11 store is fine, but somebody's house? Apparently I am the only person who makes box offsets in service masts and uses straps to hold them to the side of the houses.....


I guess I'm just too old school.


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