Did you know that a 8X8 has 64 square feet of surface?
And at 75 MPH wind it's 15 Lbs per sq foot of pressure!
That's 960 Pounds pushing on the door! A CAT 1 hurricane.
A CAT 5 hurricane?? Try 3840 Pounds! almost two tons!
Garage doors are the most vulnerable to hurricane force winds for two reasons,
first the relatively long span of opening that they cover, and second,
the weak materials they are built with.
Many garage doors are constructed of lightweight materials to conserve weight and expense. Although their lighter weight makes them easier to raise and lower, it also makes them less resistant to the wind and impact forces of a hurricane.
It may suprise you that most door tracks use 5/16 lag bolts into wood.
Looking at most failed doors the Track or door failed. Rollers came
out of the track! It bent the track door blew in! some the lags pulled out.
On a 4 section door there is 10 rollers.Sounds good? 2 inch steel rollers If
your lucky! Many now days are Nylon. All but commercial doors have short shafts.
Under high wind load the bottom of the door may flex and the short shaft roller
Can pull out of the bracket. But think of this? If you could put the door on its
side. Better yet the house on its side door facing up! Now put a 3800 pound car on it!
Think your 2 inch steel track will hold? think the track won't bend easy?
You can bend it with a pair of good size pleirs! I have fixed many tracks!
When cars have bumped them!
A wind-resistant garage door has bracing and reinforcement running vertically
and horizontally along the interior face of the door and reinforced end stiles
to keep it from twisting out of shape and dumping in.
Hear this statement from the Federal Alliance for Safe Homes: "Approximately
80 percent of residential hurricane damage starts with wind entry
through garage doors." HOMEMADE
GARAGE DOOR BRACING!
Here is some pictures of garage doors that failed!
