For buildings with low slope roofs less than 2 12 slope the wind speed at eave height is used.
Roofing wind speed ratings.
One common misconception is the belief that fm approvals windstorm classification ratings such as 1 60 1 90 or 1 120 correlate to wind speeds of 60 90 or 120 miles per hour mph.
The information is based on an.
Building owners and some specifiers and designers don t realize that the ratings apply to uplift pressures in pounds per square foot psf not wind speeds.
One thing to watch out for is an installer utilizing staples to install the roof.
A typical architectural laminate carries a 110 mph wind rating using 4 5 nails.
In most cases using staples will void the manufacturer wind rating warranty.
Class a for winds up to 60 mph class d 90 mph class f 110 mph class g 120 mph and class h 150 mph.
Building owners and some specifiers and designers don t realize that the ratings apply to uplift pressures in pounds per square foot psf not wind speeds.
One common misconception is the belief that fm approvals windstorm classification ratings such as 1 60 1 90 or 1 120 correlate to wind speeds of 60 90 or 120 miles per hour mph.
The height of the roof and exposure and risk categories are factors that are used to convert design wind speed to an uplift pressure.
Wind loads are based on the design wind speed which is based on the geographic location of the building height of the roof exposure category roof type enclosure classification and risk category.
Clay and concrete tile roofing has been tested in accordance with 2017 florida building code residential sixth edition to meet section r 4402 high velocity hurricane zones roof assemblies and rooftop structures with wind speeds up to 150 miles per hour.
This type of roofing material is classified based on windspeed resistance and with wind ratings categorized as follows.
Since local wind speed is the common factor in all three an understanding of how wind speed is used associated to each needs to be clarified.
Roof design wind pressures are determined using the wind speeds at the mean roof height of the building i e average of the eave and ridge heights.
The same shingle qualifies for a 130 mph wind rating level 5 hurricane if you use 6 fasteners per shingle.
