The following calculation program is provided as a reference for architects, specifiers, and roofing contractor to determine the appropriately tested adhered or mechanically fastened membrane roofing system for a particular project. This program will be used in conjunction with Carlisle Specifications and requirements of a specified products and systems under consideration.
This program is modeled after the ANSI/SPRI WD-1 “Wind Load Design Standard Practice for Roofing Assemblies 2007” (which is based on the ASCE 7-05 document titled “Minimum Design Loads For Building And Other Structures”) to provide an easy method for determining wind uplift pressures for any building.
After determining the uplift pressure, the specifier must review roofing systems that have been successfully tested through an independent testing agency or Factory Mutual Global to ensure they exceed the calculated uplift pressure.
Please note only roof slopes <= 10° are addressed by this program. This program does not apply to Ballasted Systems since ballasted systems cannot be tested based on uplift pressures. For ballasted roofing systems, refer to the latest published ANSI/SPRI RP-4 reference document titled “Wind Design Standard For Ballasted Single-Ply Roofing System”.
Items such as wind direction, gust effect, steep-sloped roofs (> 10º ), affects of hills, ridges and escarpments and large volume reduction factors (all contained in ASCE 7-05) have not been included. If these factors are applicable to a particular building, consult ASCE 7-05 or a design professional.
Instructions:
Prior to running this program, the user should have the following information available to apply as required. Deck type, building height, location, use of building, any large door openings and any safety factor requirements.
