How to Paint Roofing and Cladding

Painting roofing and cladding is one of the most effective ways to restore, protect, and extend the life of a building’s exterior. Whether it’s metal cladding, industrial roofing sheets, or building façades, the right coating system can improve weather resistance, prevent corrosion, and transform the overall appearance of your property.

At New Guard Coatings, we supply a full range of roofing and cladding coatings designed to deliver long-term protection and durability, even in harsh industrial and coastal environments.

Why Paint Roofing and Cladding?

Over time, roofs and cladding are exposed to UV radiation, moisture, temperature changes, and pollution. Without maintenance, this leads to colour fading, chalking, corrosion, and general degradation. Painting these surfaces provides:

  • Corrosion protection: Shields metal from rust and weather damage

  • UV and colour stability: Keeps the surface looking newer for longer

  • Extended lifespan: Delays the need for full replacement

  • Improved energy efficiency: Light-coloured coatings reflect sunlight and reduce heat build-up

  • Enhanced appearance: Refreshes tired or faded panels for a professional finish

Step 1: Inspect and Prepare the Surface

Before painting, it’s essential to assess the condition of the roof or cladding. Look for signs of corrosion, flaking paint, chalking, or loose fasteners. Proper surface preparation is key to achieving lasting results.

Typical preparation steps include:

  • Cleaning: Remove dirt, grease, and debris using a pressure washer or detergent solution.

  • Rust removal: Mechanically clean rusted areas with a wire brush or abrasive blasting, then apply a rust converter or zinc phosphate primer.

  • Old coating removal: Any loose or flaking paint should be stripped back to a sound surface.

  • Rinsing and drying: Always allow the surface to dry completely before coating.

Step 2: Apply the Primer

Priming is essential for ensuring good adhesion and corrosion resistance, especially on bare or previously weathered metal. The type of primer depends on the substrate:

  • Galvanised steel: Use an etch primer or two-component epoxy primer for strong adhesion.

  • Bare steel: Apply a zinc-rich epoxy or anti-corrosive primer.

  • Previously coated surfaces: Use a high-build adhesion primer suitable for overcoating existing finishes.

Allow the primer to dry as specified on the Technical Data Sheet (TDS) before applying the next coat.

Step 3: Choose the Right Topcoat

Selecting the correct topcoat depends on exposure conditions, colour requirements, and desired finish. Common choices include:

  • Acrylic roof coatings: Flexible and UV-resistant, ideal for general maintenance.

  • Polyurethane coatings: Highly durable and resistant to UV degradation and chemicals.

  • Silicone-modified coatings: Excellent water resistance and longevity for exposed roofs.

At New Guard Coatings, we supply Jotun, Hempel, and other premium brands that meet international performance standards for roofing and cladding protection.

Step 4: Application Method

Roofing and cladding coatings can be applied by airless spray, brush, or roller. For large surfaces, airless spraying offers the best efficiency and uniform finish.

Apply the coating in even passes, overlapping each section slightly to avoid streaks or missed areas. Most systems require two coats for full coverage and durability.

Always respect the recommended overcoating times and film thickness (DFT) for best results.

Step 5: Allow to Cure

After the final coat, allow the system to cure fully before exposure to rain or heavy conditions. Curing times vary based on the product type, temperature, and humidity.

Avoid applying coatings in poor weather or direct sunlight, as this can affect adhesion and drying.

Common Mistakes to Avoid

  • Painting over dirty or rusted surfaces

  • Ignoring primer requirements for different metals

  • Applying coatings too thickly or too soon between coats

  • Coating during damp or windy conditions

Recommended Products for Roofing and Cladding

At New Guard Coatings, we offer a range of specialist products for roof and cladding protection, including:

  • Jotun Penguard Primer – anti-corrosive epoxy primer for metal substrates

  • Jotun Hardtop Flexi – polyurethane topcoat offering excellent flexibility and UV resistance

  • Jotun Roofcoat – single-pack acrylic coating ideal for maintenance and refurbishment

  • Rust converters and surface prep cleaners – to restore and stabilise aged metal

Our technical team can recommend the best system for your project based on substrate, environment, and desired longevity.

Contact Our Team

For expert advice on painting roofing and cladding, or to select the right coating system for your project, speak to our team today.