[TowerTalk] Rohn House Bracket and Stucco Siding

chasm at texas.net chasm at texas.net
Sat Jul 5 04:53:16 EDT 2008

David Robbins K1TTT wrote:
> Only a proper architect could tell for sure... but I would be afraid of the
> bracket cracking the stucco.  Remember, the bracket takes all the side
> forces on the tower so its going to be pushing and pulling on that spot as
> the wind changes.  So personally I would go with a separate ledger board and
> be sure to bolt well into the inside structure.  Remember, lag bolts into a
> 2x4 wall probably won't hack it... the note in my older rohn catalog about
> house bracket installation is "the interface of tower brackets to supporting
> structure is to be designed 'by others' and must support a minimum
> horizontal force of 815 pounds."  The way I look at that is to picture the
> attachment point with the wall laying on its side and think about 5 people
> hanging from it, if you aren't comfortable with that its probably not strong
> enough.   David Robbins K1TTT

all that is true enough but...
the original post does not state how deep in the ground his foundation 
how high he plans to go with how much guying.
how much load he plans to have on top

point is, if he has half a section or so of tower in concrete, he very 
  nearly stand alone up to about 20', maybe further.  in some areas, 
perhaps as much as 35' before he needs guys.

He has little if any moment of overturn acting in a wall bracket with 
a good foundation.

another point, is he anchoring against a one story eave or a two story 
or ???

just too many questions but certainly, I agree.  a 2x6 should be lag 
bolted into the studs or more likely, into the rafter ends of his roof 
fascia.  4 feet of concrete will reduce his needs for a wall bracket 
greatly.  Proper guying with the foundation would eliminate the 
bracket entirely.  But, that is just from experience.  I am no PE.<G>

73 de chas/ k5dam

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