Window and Door Glass - Important Info!

[borderPatrol2329]

I hope I can offer some information that may help some of those who may find themselves in the path of Frances. This information may already be common knowledge to you. If so, my apologies for wasting board space. If not, I hope this provides you with some additional resources to protect you, your loved ones, and your property.

The biggest factor in structural failure in buildings during Hurricanes and Tornadoes has been attributed to the failure of doors and windows. The reason for this is when a door or a window fail, the wind screams through the opening and becomes trapped in the confines of the structure. This piling up of wind is referred to as STACK PRESSURE. This pressure builds until the weakest part of the structure gives, usually the roof. When the roof lifts, the unsupported walls soon collapse.

That's only part of it. A CAT-5 may have gusts of 180mph. A wind of 180mph exerts a force of 83lbs per square foot. Imagine, if you will, a large window bowing inward under this incredible force. Now add in some airborne debris. When an object breaks glass that is under such incredible force, it will release with explosive and very lethal force. As well, these large shards of glass now become flying guillotines. Large hunks can travel great distances, and can penetrate all but solid masonry structures.

Not everyone is going to be able to secure plywood or other material for a proper board up, so what can they do? Duct tape will be your best ally. Start with each window and create an X from corner to corner. Now create a cross from the mid points of the window. Now run the tape around the perimeter, half on the glass, and half on the frame. Overlap on strip to the inside, and on strip to the outside of you perimeter strip. Repeat this procedure on the opposite side of the glass. On the interior side of the glass apply a clear piece of polyethylene tarp (or kitchen cling wrap if you can't obtain polyethylene) with more tape. This is to protect you from spall. Spall is small splinters of glass ejected when glass is shattered. Be aware that all high strength glass, except that which has special film applied, is prone to spalling.

Tempered safety glass is very, very vulnerable to failure in Hurricanes. While it will withstand 4 to 5 times greater impact and windloading to regular glass of the same thickness, when it does fail, and it will, it basically disintegrates into 1/4" size pieces. Tempered glass launched by hurricane force winds will act like buckshot. Most entry doors, storm doors and patio doors are tempered glazing. Sloped glazing and some rooftop skylites may also be tempered glass, particularly if they are single glazed. You need to secure and protect tempered safety glass from any chance of impacts, and from excessive loading.

Assessall of your windows and doors. Factors that affect their strength are glass thickness, size, and shape. The thinner the glass, the more likely it will break when under Hurricane windloading. Similarly, even with thicker glass, large windows are more at risk. Shape can also play a part. Rectangular windows tend to fail ahead of square windows. This is because square windows distribute the loading equally to all points of the frame. So what can you do to shore up large windows short of boarding them up? Use broomsticks, poles, rods, or any sturdy material as a support. Don't get carried away and use something too large(thick), as it may break loose under its own weight at the height of the storm. Use the duct tape to securely fasten your piece of material across the center of the window on its widest side (not diagonally). If you have sufficient material, put it across the opposite side on the interior. This is for the negative loading (vacuum effect) on the leeward side. Be sure you material extends well beyond the frame. Be certain that it is well taped so that it doesn't become the missile that ends up breaking your window.

Lock and secure all doors and windows. Tape cam locks to prevent them from popping open from wind vibrations. Brace inward opening doors, and large windows with large, heavy pieces of furniture. Take shelter in a small inner room in the house, line the walls with mattresses and other padded type materials to act as a cushion to absorb the inertia of flying debris. Stay as low to the ground as you can.

About riding it out in the big city, or any other area in the immediate vicinity of retail, or commercial areas that have lots of glass. Think of your actions as taking shelter with a bunch of smokers in a gunpowder factory. Perhaps you feel safe because you are not near the eye. There is something called the effect of elevation on wind velocity. In essence, wind velocity tends to increase with height above the ground. Thus a 60mph wind at ground level may be a 90mph wind at the 22nd floor. Safety glass isn't very safe when it breaks free as one piece from a damaged frame and is propelled by the wind.

At Hurricane shelters, keep a solid masonry wall between you and any exterior windows.

I sincerely hope this information proves of value. To any and all of you that should find themselves in Frances path, good luck, God bless, and may you through completely unscathed.

[Dean4Storms]

I might add.... remove your screens before the storm, if your windows fail or you lose power and still have a roof overhead you can at least put your screens back in your windows and keep the bugs out. Remember with no power you will want your windows opened and if the screens are damaged or gone you will be sleeping with bug repellant on.