Chalking

The gradual change in the appearance and properties of a material caused by outdoor exposure to ultraviolet radiation, moisture, temperature cycling and airborne pollutants. Coating and material durability is assessed by natural exposure trials and by accelerated weathering tests in the laboratory.

An additive that protects polymers, coatings and sealants against degradation by ultraviolet light, either by absorbing the radiation (ultraviolet absorbers) or by scavenging the free radicals it generates (hindered amine light stabilisers). It is used to delay chalking, colour fade and embrittlement in exterior applications.

The final coat of a coating system, providing the specified colour, gloss and resistance to weathering, ultraviolet light and chemical exposure. It is the system's first line of defence against the environment and largely determines how the finish looks over time.

A coil or spray applied architectural coating based on polyvinylidene fluoride resin, valued for outstanding colour and gloss retention and resistance to ultraviolet light and chemical attack. It is commonly specified for premium metal roofing, cladding and curtain walling.