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Galvanic Corrosion in Gutter Guard Systems: What Homeowners Need to Know
May 13, 2025 Simon Aldridge

Galvanic Corrosion in Gutter Guard Systems: What Homeowners Need to Know

Integrated mesh gutter guard and leaf guard systems, particularly those made from powder coated aluminium mesh, are an increasingly popular solution for protecting gutters from debris, pests and extending the life of your roof drainage system. While these systems offer substantial benefits, it’s crucial to understand the risks of galvanic corrosion-especially when selecting materials-to ensure your gutter guard system remains effective and durable for years to come without affecting the integrity of your roof and home.

What is Galvanic Corrosion?

Galvanic corrosion is an electrochemical process that occurs when two different metals come into electrical contact in the presence of moisture. In this scenario, one metal (the less noble) corrodes faster than it would alone, while the other (the more noble) is protected. This process is particularly relevant in gutter guard and leaf guard systems, where mesh, screws, and brackets may be made from different metals and are constantly exposed to rain and humidity.

Difference Between Galvanic Corrosion and Rust

Galvanic corrosion and rust are both forms of material degradation, but they differ in their causes, affected materials, and appearance.

What is Rust?

  • Rust is a specific type of corrosion that only affects iron and its alloys, such as steel.
  • It occurs when iron reacts with oxygen and moisture, forming iron oxide, which is typically red-brown and flaky.
  • Rust weakens the metal, causing it to become brittle and deteriorate over time.

 

What is Galvanic Corrosion?

  • Galvanic corrosion is a broader type of corrosion that occurs when two dissimilar metals are in electrical contact in the presence of moisture.
  • One metal (the less noble) corrodes faster than it would alone, while the other is protected.
  • This process can affect a variety of metals, not just iron or steel. For example, aluminium can corrode rapidly if it is in contact with steel in a wet environment

How Galvanic Corrosion Impacts Gutter Guard Systems

Gutter guard systems often involve several components-such as powdercoated aluminium mesh, steel screws, and various brackets-that may not always be made from the same metal. When incompatible metals are used together (for example, aluminium mesh installed on steel gutters), the less noble metal, often aluminium, can corrode rapidly. This accelerated corrosion can compromise the effectiveness of your gutter guard or leaf guard, leading to premature failure and potentially costly repairs.

Signs of Galvanic Corrosion in Gutter Guard and Leaf Guard Systems

Be vigilant for these common indicators of galvanic corrosion:

  • Localised rust or pitting where different metals meet.
  • Discolouration or rapid deterioration of the gutter guard mesh or fasteners
  • Reduced structural integrity or loosening of the gutter guard components.

Early detection is key to preventing further damage and maintaining the performance of your gutter protection system.

Preventing Galvanic Corrosion in Gutter Guard Installations

To ensure your gutter guard or leaf guard system stands the test of time, follow these best practices:

  • Use Compatible Metals: Always match the mesh, fasteners, and adjoining roof/gutter materials. For example, use powdercoated aluminium mesh with aluminium gutters and aluminium fasteners, or zinc-coated steel mesh and screws with steel gutters.
  • Separate Dissimilar Metals: Where different metals must be used, separate them with non-conductive barriers such as the powdercoat on the mesh.
  • Professional Installation: Engage experienced installers who understand the importance of material compatibility and proper installation techniques to minimise corrosion risks.

Best Practices for Material Selection

Choosing the right materials for your gutter guard or leaf guard system is essential:

  • Match Materials: Select gutter guard mesh and fasteners that are compatible with your existing gutter and roof metals for optimal performance.
  • Opt for Quality Coatings: Use professionally coated or treated metals such as powder coated aluminium or Colorbond® for added protection against corrosion.
  • Avoid Mixed-Metal DIY Kits: Steer clear of low-quality or mixed-metal components, which can accelerate galvanic corrosion and reduce the lifespan of your gutter guard system.

Maintenance Tips to Minimise Corrosion Risk

Regular maintenance can significantly extend the life of your gutter guard or leaf guard system:

  • Inspect gutter guard mesh and fasteners regularly for early signs of corrosion.
  • Keep gutter guards clean and free of debris to reduce moisture retention, which can promote corrosion.
  • Promptly replace any corroded components with compatible materials to prevent further damage.

Conclusion

Galvanic corrosion is a preventable but serious threat to the longevity and performance of gutter guard and leaf guard systems. By prioritising material compatibility/selection, professional installation, and ongoing maintenance, homeowners can ensure their gutter protection investment remains effective for years to come. Careful planning and attention to detail will keep your gutters-and your home-safe from the costly consequences of corrosion.

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