Tech Today


SPRI recently published ANSI/SPRI WD-1, "Wind Design Practice for Roofing Assemblies." This standard provides a recognized consensus-developed methodology for designing wind-uplift resistances for low-slope built-up, polymer-modified bitumen and single-ply membrane roof systems that do not rely on aggregate or paver ballast to provide their wind resistances.

Two-part methodology

ANSI/SPRI WD-1 is divided into two primary parts. The first part addresses how to determine design wind-uplift loads. The second part discusses choosing an appropriate roof system by comparing factored, tested wind-uplift resistance capacities with the design wind-uplift loads determined in the first part.

In ANSI/SPRI WD-1, determining design wind-uplift loads is accomplished using 21 tables based on Building Category II, surface roughness (exposure category), building height (mean roof height) and peak gust wind zone (basic wind speed).

Log in or register for FREE access to this article and other Professional Roofing online content.

Not a user?

Register now for free access
  • Full access to every article
  • Online Web exclusive information
  • Photo gallery
  • Breaking news
  • Online classified ads

Already a user?

User name:



Forgot Your Password?