Silicone coatings are single-component, moisture-curing silicone rubber roof coating systems designed for use on sprayed-in-place polyurethane foam or other roof surfaces. These coatings can be spray-applied or hand-rolled if the job is small enough. Smallest repairs can be applied with a paint brush. Silicones are inorganic by nature and thus imperceptible to UV radiation. Unlike almost any other coating, silicone coatings do not contain UV stabilizers. Other lower cost systems may not contain enough UV stabilizers, with resulting short service life often not even exceeding 5 years. Properly applied, silicones may last for 20 years and more. Also, silicones cure quickly. In the event of changing weather, even heavy rain, coatings as new as 1 hour will not cause runoff. By comparison, many acrylics truly require a minimum of 24 hours between application and the first rain. Silicones offer excellent tensile strength and elongation. They perform well in extremely cold as well as very hot weather. Many customers broadcast granules into the freshly applied silicones for an even tougher roof.