How Long Do Cladding Coatings Last?

Factory-Applied Coating Lifespan

Most profiled steel cladding manufactured for the UK commercial market is factory-coated with either polyester or PVDF (polyvinylidene fluoride) coatings applied over a zinc or zinc-aluminium substrate. These coatings are applied under controlled factory conditions at consistent film thicknesses — which is why they typically outperform site-applied coatings in terms of initial quality.

Standard polyester coatings on profiled steel cladding typically retain acceptable performance for 15–20 years in UK conditions. PVDF coatings (marketed under trade names such as Kynar or Hylar) are significantly more durable — typically 25–35 years before significant UV degradation. Plastisol coatings, used on older UK warehouse stock from the 1970s and 1980s, were thicker but less UV-stable and often show significant surface degradation by 20–25 years.

Spray-Applied Refurbishment Coating Lifespan

A spray-applied refurbishment coating system applied by an approved applicator at the specified film thickness, over correctly prepared substrate, should deliver 10–15 years of service life in typical UK commercial environments. High-performance systems such as Rocathaan Hotspray PA 260-FR, applied at higher film builds, are specified for the upper end of this range.

These figures assume correct preparation and application. The same coating system applied over inadequately prepared substrate, at below-specification film thickness, or in unfavourable environmental conditions may fail significantly earlier. This is not a coating failure — it is an application failure.

What Shortens Coating Lifespan?

Atmospheric environment: Coastal environments (within approximately 1km of tidal water), industrial environments with acid vapour or particulate pollution, and areas with high UV intensity all degrade coatings more rapidly than standard inland commercial environments. The difference in degradation rate between a coastal and a sheltered inland location can be significant over a 15-year period.

Preparation quality: Adhesion of a spray-applied coating depends on the surface preparation standard achieved. Inadequate preparation — insufficient pressure washing to remove chalk residue, insufficient mechanical abrasion to key the surface — reduces adhesion and shortens service life regardless of system quality.

Film thickness: Coating performance is specified at a minimum dry film thickness. Applications below the specified minimum provide less UV and weather resistance and degrade faster. Film thickness measurement on completion is the only reliable method of confirming specification compliance.

Substrate condition at time of application: Applying a coating over substrate with active corrosion, failing adhesion layers, or residual moisture shortens service life. This is why thorough preparation — and in some cases, timing the application to avoid seasonal moisture ingress — matters.

What Building Owners Can Control

The timing of intervention is the most significant variable that building owners control. Refurbishing cladding at the chalking stage — before the existing coating has fully failed — provides a better preparation substrate for the new system, and typically results in a longer service life than refurbishing severely degraded cladding that requires more intensive preparation to achieve the same adhesion standard.

When Does Recoating Become Necessary?

The trigger for recoating is typically the point at which the coating's protective function has degraded to the point where corrosion will begin if further action is deferred. For most commercial cladding, this is indicated by moderate-to-heavy chalking, colour fade beyond acceptable limits, or early-stage coating delamination. It is not necessary to wait until coating failure is visible — by that point, preparation requirements are higher and overall system performance will be lower.