Factors affecting durability - external surfaces
All products used for exterior applications are designed to withstand the environment. But all are, to some extent, affected by it.
The main environmental factors which degrade pre-finished steel products are:
-
Water, oxygen and salts;
-
Sunlight;
-
Chemicals and pollutants;
-
Abrasives such as wind-blown sand and salts.
Abrasives
Abrasion can be caused by a variety of airborne particles such as wind blown sand and salts. Abrasion resistance has many manifestations, but can be typified by the effect of blowing sand. As in all aspects of durability, not all pre-finished steel products are the same in their resistance to abrasion.
Chemicals and pollutants
Chemicals and pollutants can create an aggressive atmosphere which can reduce the performance life of a pre-finished steel product not suited to that environment.
Sunlight
Light energy falling on the earth includes light we can see, from red to blue, and lights we can’t, such as Ultraviolet (UV) and infrared. In general, any form of electromagnetic energy can be characterised by its wavelength. The visible region of the electromagnetic radiation spectrum runs from about 400 to 700 nm. UV light falling on the earth has a wavelength between 300 and 380 nm and infrared between 780 and 3000 nm.
Water, oxygen and salts
Everyone is familiar with the principle of corrosion in its most advanced state in examples like rusty old nails. But with modern, long-life pre-finished steels, the corrosion process is prevented for decades.
