As I said in my initial post....better back-guy the house, the
trusses aren't designed for lateral load resistance! Even if I'm
wrong by a factor of 2 on the dead-weight of the guys, it's still
over 100k lbs. de N2EA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I concur with what Jim says. I have a Florida general contractors license
(inactive now), and anyone who has ever handled trusses and installed them
knows
how flimsy they are when handling a lateral load, barely able to support
themselves in a horizontal position. They are designed for a vertical load.
The
main stiffening for the lateral load is done by the sheeting, usually 1/2 inch
plywood held on by 8d nails...not my idea of the kind of system to support
the tower you plan to install.
My guess it would work fine for 70 feet of Rohn 25 or maybe even 45, but not
for the monster you want to build.
By the way, I have seen CBers and hams anchor some big towers to roofs...not
always a good idea either. Trusses are made to support downward load, not
horizontal and vertical, which are created by the guys. In Florida all lower
chords of trusses now have extra cross member stiffeners, and roof overhangs
have
been reduced to very small size......to counteract the same forces created
when guying a tower to the roof..........and hurricanes.
Bill K4XS.......sweating out the start of a the new hurricane season starting
today.
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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