Zones, Uplift Pressures and Demonstrating Compliance
What Do I Need to Know and Where Do I Find It? Mike Silvers, CPRC, Owner of Silvers Systems Inc. and FRSA Technical Director It seems like almost all I talk about lately is ASCE 7-16. If you’re roofing in Florida and haven’t heard about it, maybe you haven’t been paying close enough attention. The updated 2020 Florida Building Code (FBC) 7th edition reference standard has certainly shaken things up. From contractors to building officials, there is a lot of confusion, so don’t feel alone. The American Society of Civil Engineers Structural Engineering Institute (ASCE/SEI) produces the ASCE 7 standard which provides the information (among many other things) to calculate the uplift or negative pressures for components and cladding. I will be referring to these as “pressures” in this article. Roof coverings are considered cladding. The December 2020 issue of Florida Roofing magazine contains the article “Does ASCE 7-16 Really Change Everything?” It details methods to establish the location and size of zones and the applicable uplift pressures that are now required to be resisted in up to six different zones. Keep in mind,
these pressures do not directly apply to asphalt shingles or metal shingles which, use miles-per-hour wind resistance tables. All other roof coverings need to resist these pressures. Assuming that you know the pressures that the roof covering needs to resist, how do you find the right system to use and how to attach it? There are several different approaches to get the needed information. I will cover a few here. As contractors, one of our best sources of information are our manufacturer’s representatives. Many will not only help with attachment methods to achieve the needed resistance but can also help with plotting the zones and establishing the pressures for your projects. If you are lucky enough to have this resource available, you will still need an understanding of the basic information needed to produce the results you are looking for. This is covered in the above-mentioned article. If the manufacturer of the roof covering you’ve chosen
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FLORIDA ROOFING | March 2021
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