Damaging Winds

As you know by now I'm obsessed with the damage wind can do. I just found this great article called "The Hidden Story of Storm Protection." by Frank Bennardo, P.E. Few people realize how complex and pervasive wind can be on a structure, but he breaks it down into easy to understand terminology. I didn't fully realize that the second function of a shutter is to reduce internal pressurization. The ability for wind to get into any and all spaces brings to mind a condo a few months ago that I got a chance to evaluate, which essentially failed during Hurricane Wilma because a resident (understandably) got scared when the violent winds shook the building and his balcony windows imploded.

This is what happened:

1) The implosion of the balcony windows suddenly increased the air pressure and flying glass shatter inside the apartment.

2) Panic took over and the residents forced the entrance door to open establishing a wind tunnel inside their hallway corridor. Once outside the door was released and slammed violently.

3) The pressure difference and the molecules expanding and contracting within his condo found its way into the interior hallway and blew the corridor's exterior exit door open, equalizing the full pressure difference and releasing energy towards the interior partition walls which collapsed.

4) Additional energy sources came into play such as stairwells to the roof exit and continued the destruction of interior walls and finishes.

Unfortunately, as demonstrated during Hurricane Wilma, even a small breach of the building envelope will impose excessive loads which can lead to failure. Do it right....get it engineered!