Post-Painted Factory Applied finish

This coating system is most commonly used for pressed metal tiles.

Where a coating is applied to a Metallic coated steel or Aluminium substrate after the profile of the roofing sheet has been formed is referred to as a Post-Painted Factory Applied Finish. The metallic substrate may have a coil-coated primer, coil-coated anti-fingerprint coating, a factory-applied post-painted primer or be cleaned and treated to suit the application of the coatings in a factory environment.

Post-painted coating applied to the substrate varies from smooth matt or gloss-painted finishes and textured granule finishes bonded to the substrate with high-build coatings. The dry film builds are high compared to pre-primed or coil-coated products and the films seal any micro-cracking of the metallic coating that may have occurred in the forming process.

The corrosion performance of the post-painted factory-applied finished products is influenced by the substrate. The use of Aluminium Zinc metallic coating (AZ) has been proven to work extremely well with post-painted finishes in almost all environments.

The coatings are durable with expected first-time recoating maintenance of over 15 years. Touch-up of these coatings is possible as the same coating formulation can be applied in the field. As with any organic coating, there will be a gradual breakdown of the resin systems which may result in chalking of the surface.

Chalking is the result of erosion of the surface coating and slight colour changes may occur as the surface resin is eroded. The extent of change depends on the pigments used and also the gloss level, a coating that started as a matt finish will change very little while a gloss finish will appear to have changed more.

Granule-textured finishes are created using crushed rock, comprising either natural rock or natural rock coated with a ceramic finish containing light-fast inorganic pigments. Both the natural rock and ceramic-coated granules provide exceptional long-term colour durability. The coatings used to adhere the granules to the substrate are designed to be flexible in all environments and, although durable, the coating is protected from UV by the UV opaque granules.

A clear coating is applied to the granules during the coating process, which helps bond the granules into the adhesive base coating and provides a robust surface reducing any damage during the transportation and installation process. As this clear coat weathers, it exposes the natural or coated surface of the granules, which is slightly duller than the initial finish.