UL: Underwriters Laboratories, Inc.
Ultraviolet light (UV): a form of luminous energy occupying a position in the spectrum of sunlight beyond the violet, and having wavelengths that do not enter the visible spectrum. UV rays accelerate deterioration of roof materials. Hence, the need for protective coatings.
Underwriters Laboratories, Inc (UL): an organization that tests, rates and classifies roof assemblies for their resistance to fire, impact, leakage, corrosion or metal components and wind uplift.
Uplift: see Wind uplift.