Touch up of pre-painted cladding

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We regularly receive enquiries as to where one can source touch up paint to repair damaged pre-coated coloured cladding. Our standard answer is; DON’T EVEN THINK ABOUT IT.

Firstly the mill (factory) applied coating is a specially developed and durability tested three part system comprising a chemical pretreatment of the metallic coating applied to the steel substrate, primer coat and top coat. Both the primer and top coats are oven baked. It is naïve to believe that a single coat of air dried paint will match the service performance of the mill applied coating system. Within a very short period of time, usually less than a year, the touch-up coat fades to a lighter colour resulting in a mottled appearance. At best the size of the brush used to apply the touch-up paint converts fine hairline scratches into a different coloured stripe, blob, etc. As a general rule, in all but the most aggressive environments, if the scratch is less than 1.5mm wide, has not penetrated the protective metallic coating under the paint system and is not visible from a distance of 5.0m leave it be. Over spraying an entire section may eradicate the mottled effect but will not solve the problem of differential fading. If the damage falls outside these criteria then, unfortunately, the cladding will have to be replaced.

Another point to remember is that many of the mill applied coats have enhanced solar reflective properties.

This is definitely a case of prevention is better than cure. Remember the cladding is there to provide a weatherproof envelope and aesthetic appeal and not to provide a working platform to all and sundry. The worst culprits are the wet trades with their bricks and mortar. A painted coating on which wet cement based products are allowed to dry before being removed (often mechanically with a spade) are irreversibly damaged. Every effort needs to be made to complete all wet work prior to the cladding being installed, failing which the surface is to be covered with a suitable waterproof cover, extensive enough to prevent runoff flowing across the painted surface plus the areas where workmen are active or materials stored are topped with duckboards.

Most colour coated coil manufacturer’s warranties are negated if another coating is applied to the surface of the cladding.