Metal roofing is prized for its durability, but even the toughest materials eventually show signs of aging, oxidation, and wear. When your metal roof begins to fade, chalk, or develop rust spots, many property owners face a critical question: Can you successfully paint or coat a metal roof to restore its appearance and extend its lifespan?
The simple answer is yes—but achieving professional, long-lasting results requires the right products, preparation, and application techniques. Shieldcoat has developed specialized coating systems specifically engineered for metal roofs of all types and conditions. This comprehensive guide explores everything you need to know about coating metal roofs with Shieldcoat products.
One of the most significant challenges in roof coating is that not all metal roofs are created equal. Different metal substrates require different approaches to ensure proper adhesion, corrosion protection, and long-term performance. Shieldcoat stands apart as one of the few manufacturers offering specific solutions for every type of metal roofing:
Colorbond is a popular pre-painted steel roofing product in Australia. As it ages, its factory-applied finish often begins to chalk and fade, creating adhesion challenges for new coatings. Shieldcoat has developed specific primers that penetrate and bind this chalky surface, creating the perfect foundation for topcoat adhesion.
This zinc-coated steel provides excellent corrosion resistance when new but eventually weathers and develops a patina. Coating these surfaces requires products that can bond with the zinc surface while providing flexibility to accommodate the natural expansion and contraction of the metal.
Traditional corrugated iron presents unique challenges due to its distinctive profile and tendency to develop rust at overlaps and fastener points. Shieldcoat's system addresses these trouble spots while providing complete coverage across the corrugations.
Rusty metal requires specialized treatment to stabilize the corrosion process before coating. Rather than requiring complete rust removal (which is often impractical), Shieldcoat's rust primers convert and encapsulate the rust, creating a stable surface for the protective membrane.
Shieldcoat's approach to metal roof coating involves a complete system rather than just a topcoat. This systematic approach ensures maximum adhesion, durability, and protective properties:
Proper preparation is critical for any coating project, but especially for metal roofs:
Cleaning: All surfaces must be thoroughly cleaned to remove dirt, mold, mildew, and contaminants. Shieldcoat Mould Rid provides industrial-strength cleaning without damaging the underlying metal.
Pressure Washing: After chemical cleaning, high-pressure washing removes all residues and loose material. This step requires careful technique to avoid damaging the metal surface.
Repairs: Any damaged areas, loose fasteners, or failing seams must be addressed before coating. Shieldcoat offers specialized repair products for different metal roofing issues.
Once clean and repaired, the metal surface requires the appropriate primer:
Rustshield Primer: For surfaces with rust, this specialized primer penetrates, converts, and encapsulates oxidation while providing an anchor for the topcoat system.
Metal Etch Primer: For new, non-rusted galvanized or Zincalume surfaces, this primer etches into the metal for superior adhesion.
Colorbond Primer: Specifically formulated to bind with and stabilize chalky, weathered Colorbond surfaces, preventing future chalking while creating an ideal surface for topcoat adhesion.
After proper preparation and priming, Shieldcoat offers several topcoat options depending on your needs:
Roofbond Membrane: A premium acrylic coating that provides excellent protection, color retention, and weather resistance. Available in both standard and heat-reflective formulations.
Thermabond: For maximum energy efficiency, this specialized heat-reflective coating reduces heat transfer into the building, potentially lowering cooling costs and improving comfort.
Shieldseal: Where maximum waterproofing is required, this elastomeric coating creates a seamless, flexible membrane that accommodates the natural movement of metal roofing.
Choosing a complete Shieldcoat system for your metal roof offers several key benefits over generic paint products or partial solutions:
A proper coating system doesn't just improve appearances—it actively protects the metal substrate from further deterioration. By preventing moisture penetration and UV damage, a quality coating system can extend your roof's functional lifespan by 10-15 years or more.
Generic paints often fail prematurely on metal roofs due to poor adhesion. Shieldcoat's substrate-specific primers are engineered to create the strongest possible bond with each type of metal surface, even challenging ones like weathered Colorbond or partially rusted steel.
Metal roofs expand and contract with temperature fluctuations more than other roofing materials. Shieldcoat's coatings are formulated with elastomeric properties that allow them to flex with the metal without cracking or delaminating.
Beyond simple color restoration, Shieldcoat systems provide active corrosion protection by sealing the metal surface from moisture and oxygen—the two elements necessary for rust formation.
With options like Thermabond, a Shieldcoat coating system can significantly reduce heat transfer through metal roofing, potentially lowering cooling costs and improving interior comfort during hot weather.
Perhaps most importantly, Shieldcoat's complete systems come with warranty protection—something generic paints or partial systems cannot offer. This warranty coverage provides peace of mind that your investment is protected.
Metal roof coating projects present several unique challenges that Shieldcoat's systems are specifically designed to address:
Solution: Rather than requiring complete rust removal (which is often impractical), Shieldcoat's Rustshield primers penetrate, convert, and encapsulate rust, creating a stable foundation for the topcoat system. These specialized primers contain corrosion inhibitors that prevent future oxidation while providing an anchor for the membrane topcoat.
Solution: As Colorbond ages, it releases chalk—microscopic particles of the original coating that create adhesion problems. Shieldcoat's Colorbond primer is specifically formulated to penetrate this chalky layer, binding it to create a stable surface for the topcoat. This specialized approach prevents the peeling and flaking common with generic paint products.
Solution: Metal roof failures often begin at fastener points and overlap seams where water can collect. Shieldcoat's system includes specific preparation techniques for these vulnerable areas, ensuring complete coverage and superior protection at these critical points.
Solution: Metal roofs in Australia face some of the world's harshest UV conditions. Shieldcoat's membrane topcoats contain advanced UV stabilizers and fade-resistant pigments that maintain color integrity and protective properties even after years of sun exposure. The company's color fade guarantee provides assurance of this performance.
While Shieldcoat products are available for both professional and DIY applications, there are important considerations when deciding whether to tackle a metal roof coating project yourself:
Safety expertise: Professional applicators have the proper equipment and training to work safely at heights.
Substrate assessment: Professionals can accurately identify your specific metal roof type and condition, ensuring the appropriate system is used.
Preparation knowledge: The keys to success lie in proper preparation, which professionals have mastered through experience.
Application efficiency: Professional spray equipment provides faster, more uniform coverage than roller application.
Warranty benefits: Many warranty protections are only available with professional application.
Safety requirements: Working on roofs requires proper safety equipment and procedures.
System selection: Accurately identifying your roof type and selecting the appropriate primers is critical.
Preparation time: Proper cleaning, rust treatment, and preparation can be more time-consuming than the actual coating application.
Application tools: While roller application is possible for DIY projects, it requires technique and patience to achieve uniform results.
To illustrate the effectiveness of Shieldcoat's metal roof coating systems, consider this real-world application:
A 30-year-old corrugated iron roof in coastal Queensland showed significant rust development at fastener points and overlaps, with general surface oxidation throughout. The original galvanized coating had worn away in many areas, leaving the steel vulnerable to accelerated corrosion.
After thorough inspection, the Shieldcoat application team:
Cleaned the entire roof surface with Mould Rid to remove accumulated contaminants.
Pressure washed at appropriate PSI to remove loose rust and debris without damaging the metal.
Applied Rustshield primer to all rust-affected areas, converting and encapsulating the corrosion.
Applied Metal Etch primer to the remaining metal surface for maximum adhesion.
Applied two coats of Roofbond membrane in the client's chosen color.
The result was a completely rejuvenated roof with a 10-year warranty against color fade and peeling. Beyond aesthetics, the system sealed vulnerable areas against moisture penetration, effectively stopping the corrosion process and extending the roof's functional lifespan by an estimated 15+ years—a fraction of the cost of roof replacement.
So, can you paint a metal roof with Shieldcoat? Absolutely—and the results can be transformative when using a complete, substrate-specific system. While generic paint products might provide a temporary color change, only a properly engineered coating system delivers the adhesion, protection, and longevity needed for Australian conditions.
Shieldcoat's position as one of the only manufacturers offering guaranteed solutions for every type of roof substrate reflects the company's specialized expertise and commitment to quality. Whether your metal roof is relatively new Colorbond showing the first signs of fading, or decades-old corrugated iron with significant rust development, there's a Shieldcoat system designed specifically for your needs.
For property owners considering metal roof restoration, the message is clear: the right coating system not only rejuvenates appearance but actively extends roof lifespan, improves building performance, and provides warranty-backed peace of mind. With proper preparation and application, a quality coating system transforms a deteriorating liability into a protected asset that will perform for years to come.
Ultrashield Interior Low Lustre provides a hard wearing, washable low sheen finish. It has been formulated to include all the features of the most expensive paints on the market, without the price tag.