Composition of typical Decra tiles
Each Decra tile is comprised of seven layers, designed to provide unrivalled weather protection.
At the centre is the steel core, which is then hot dipped galvanised typically using zinc aluminium or zinc magnesium coatings to provide exceptional long-term durability. A chromate conversion layer is then put in place, followed by an epoxy coating. The topside of the tile is then covered with an acrylic resin, the stone granular coating and a final clear acrylic overglaze. A polyester coating is applied to the underside of each roof tile. This provides further protection against wind-driven salt spray. This makes Decra the ideal choice for developments in coastal locations.
How Is The Decra Tile Protected When It Is Cut?
Decra tiles require no further protection to the cut edge providing they are cut using a Decra guillotine, reciprocating saw, tin snips or nibblers. The use of the correct cutting equipment stops any destruction occurring to the protective galvanised coating and allows a protective cathodic process to take place. An explanation of the cathodic process can be seen below.
The Science Behind The Technology
Two differing metals each with a different electric potential in direct physical contact with each other and an electrolyte (water) form a galvanic cell. Within this galvanic cell electrons from the zinc atoms which have a lower electric potential transfer themselves to the steel atoms which have a higher electric potential. This charging of additional electrons to the steel atoms protects the steel from corrosion. Corrosion will only take place in any metal when electrons from a metal atom are lost into an electrolyte (water). Since the steel atoms are being charged with electrons corrosion will not take place.