Expert: Bruce E. Johnson - 9/12/2008

Question
I am in the process of trying to figure out how to choose windows, based on wind speed/wind loading, for new construction in Florida. I just purchased ASCE 7-05, and I know my area has a basic wind speed of 100 mph. My understanding is windows are rated (for wind speed) in pounds per square foot - plus and minus. I understand the plus and minus. I know it is positive and negative pressure. How do I use the book I purchased to find the required psf rating for windows, in my area, from the basic wind speed?

Thank you - Larry

Answer
Hi Larry, you don't need a book to intrepet window construction.  Florida building code requires that the window manufacturers state right on the window or in the window specifications what the wind loading for that window is and how it is to be installed to achieve that rating.  If a window is DADE county approved it will be acceptable for I believe 120 mph wind.  I don't think you can buy just any window anymore in this state that doesn't comply with the Florida Building Code.  Your local building department has a map outlining where your home falls in regards to wind speed and after that it is a simply a matter of choosing the windows that have the product approval for that wind speed. All window manufacturers have websites now where you can download their product approvals and specifications. I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com