Barrier Protection

Barrier protection works primarily by providing a physical barrier between the atmosphere and the steel substrate.

The surface of aluminium-dominant coatings is initially very active, but it quickly forms an inert aluminium-oxide film when exposed to normal atmospheric conditions. Aluminium dominant coatings on steel mainly provide barrier protection as the aluminium, having formed an oxide surface, ceases to offer substantial sacrificial protection.

The exposed edges of barrier protected cladding should not be in contact with corrosive surfaces. See Compatibility Table.