BoatBanter.com - View Single Post - Hurricane Irma

Mr. Luddite[_4_]

On 9/19/2017 12:28 AM, wrote:
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.

The install guy of our screen house in Florida told me that. He said
that in the event of a hurricane with winds over a certain level the
screen sections were designed to release, reducing the load on the
aluminum frame and preventing it from being wrecked. The screens are
replaceable at far less cost than the frame.

I don't recall any "cables" in the frames of either of the screen houses
we had at either of the houses we had there. Not to say they didn't
have them ... I just don't remember them and I watched one of ours being
built. The first house we bought had a pool but did not have a screen
enclosure. We contracted with an installer to put one up. I remember
that I originally wanted it to also cover part of a deck that was
between the house and the pool and that caused all kinds of problems in
terms of getting permits. It would require having a structural engineer
approve how it attached to the house which wasn't a big deal except it
would take two or three months to get it done due to a backlog of work.
We ended up opting to just enclose the pool only and the permit was
issued in a couple of days.