If you’ve ever lived or continue to live near the coast, you know how a salty sea breeze can wreak havoc on outdoor structures. Timber starts rotting and warping within a few years, and steel fixings start to rust. Before you know it, you’re back to square one with all your outdoor structures needing to be repaired or replaced. However, aluminium structures are not subject to these limitations. The properties of aluminum make it incredibly resistant to corrosion, which makes it the perfect building material for damp and coastal regions. In this post, we’ll be explaining why aluminum is the perfect building material for coastal constructions. 

Why Salt Air Is So Damaging to Outdoor Structures

In coastal areas, ocean salt particles get blown inland with the wind. Since salt is hygroscopic, it actively attracts and retains moisture. Since these particles cling to exposed surfaces, they keep structures constantly damp. The impact of salty air can depend on the material it comes into contact with. 

When it comes to metals like steel, salt dissolved in water is a powerful electrolyte. As an electrolyte, it dramatically increases the speed of the electrochemical transfer of electrons. The electron transfer disrupts protective oxide layers and increases the rate of rust. 

When salty air comes into contact with wood, the salt can pull the natural moisture out of the wood and draw humidity inside. When a cycle of moisture absorption, swelling, and evaporation occurs, the wood becomes stripped of its natural, protective oils. When the natural oils are taken away, the rot will accelerate.

How Aluminium Resists Corrosion 

If we were to be scientific about it, aluminium resists corrosion through a process called ‘passivation’. In simple terms, when aluminium is exposed to air, it forms a thin, microscopic layer of aluminium oxide (Al₂O₃) on the surface. The thin aluminium oxide barrier blocks oxygen and moisture from coming into direct contact with the raw metal surface.

Other Benefits of Aluminium Structures in Coastal Construction

Apart from being highly resistant to corrosion, there are a string of reasons why you should choose aluminium beams and structures for construction in coastal areas. The key advantages include the following:

• Minimal maintenance – Since aluminium as a material is highly corrosion-resistant, it means that aluminium structures require less routine maintenance. When maintenance is less frequent, the overall maintenance cost is also significantly less. 
• Reduced deadweight – Aluminium weighs roughly one-third of steel; the structural load it exerts is significantly less. This makes aluminium perfect for bolt-in balconies and large floating dock systems.
• Design versatility – The high strength-to-weight ratio also makes aluminium an incredibly versatile material. The feature allows them to be used in many sleek and modern architectural designs. For example, they can form the border of large glass panels that are perfect for coastal homes that want unobstructed views of the coast and ocean.
• Eco-friendly and sustainable – Aluminium is 100% recyclable, and reprocessing only requires a fraction of the energy used in the initial production.
• Thermal efficiency – Compared to many other metals and alloys, aluminium can handle heat very well. When you pair them with reflective coatings or thermal break systems, the aluminium can prevent heat transfer. This helps create cooler, more energy-efficient interiors.    

How Long Do Aluminium Structures Last in Coastal Conditions?

In coastal areas, standard aluminium structures can last 15 to 30 years. On the other hand, marine-grade alloys with thick protective coatings and routine maintenance can last between 40 and 50+ years. However, unprotected aluminium will only last about 3 to 7 years in high-salt environments. 

If you want to increase the longevity of your aluminium beams and structures, you need to look into the following:

• Alloy selection – When it’s a coastal environment, you need to use marine-grade aluminium alloys like 5005, 5052, or 5754. These alloys are naturally resistant to salt spray. However, standard 6000-series aluminium alloys won’t last long without added protection. 
• Protective coatings – High-performance coatings like PVDF or thick anodised finishes can provide an extra layer of protection from chloride corrosion and UV rays. 
• Hardware and fasteners – Fasteners in structures are major failing points, especially when corrosion-resistant materials are not used. To increase protection, use stainless steel fixing.
• Maintenance – Even with high-quality materials, make sure to wash structures once or twice every 3 to 6 months to remove any accumulated salt deposits.

Conclusion

Buildings and structures on the coast have to contend with the elements on a daily basis. However, the elements shouldn’t compromise your constructions, especially when you have many high-quality aluminium structures to choose from. Aluminium is corrosion-resistant, termite-proof, non-combustable, and built to last. In fact, they are the perfect materials for outdoor coastal constructions. 

If you need high-quality aluminium, Spanmor is the place for you. From decking systems to pergolas, our aluminium beams and structures are designed to look great, perform better, and save you during installation.