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[email protected] gfretwell@aol.com is offline
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First recorded activity by BoatBanter: Jul 2007
Posts: 36,387
Default Hurricane Irma - After Action Report

On Mon, 18 Sep 2017 15:09:53 -0400, "Mr. Luddite"
wrote:

A truly strong wind against the long side would probably toss it over
but you don't really get Cat3 and 4 up there. The direction of the
wind also makes a huge difference. You can see that, just driving
around my neighborhood If it is hitting the corner I doubt it sees
much at all except the racking force and those pegs will absorb a
whole lot of that. It is the racking that kills screen cages. When I
had mine built to the 140 mph code they added a bunch of rigid cross
members at angles across the roof to stiffen it up. I have had 3 major
hurricanes and it seemed to work.



The other thing is that the screen panels on the pool enclosures down
there are designed to pop out, reducing the "sail" effect caused by the
wind. Screens really don't have as much conductance for wind or even a
breeze for that matter. They are designed to keep the bugs out.


Where did you hear that? The standard screen "patio" material uses
flat spline that gets tighter, the harder you pull. Screens come out
when the screen tears, not because it "pops out" of anything. When you
replace it, you have to pry the spline out and dig out the screen
under the spline.
This is the cross section of a 1x2 screen cage member (usually used to
hold screen on the side of a 2x2 that does not have the spline groove)
The top right is the screen groove and the "C" shaped extrusions hold
#8 screws when you are putting them together.

I agree the screen does catch a lot of wind and even more when there
is driving rain. That is why these things are made to be so tough.
They are really engineered more like biplane wings than bridges. That
is how they get away with so little aluminum. The key is steel cables
holding the whole thing together. I did some post portems on failed
cages at my wife's (Centex) community after Charley and every one
seemed to fail when a cable anchor failed. After that they started
racking and just came apart. I do know I added extra cables to mine
after that.