Life on the coast has its perks — nice views, fresh sea air, and an abundance of ice cream parlours. However, for builders and architects, the seaside also presents some serious challenges. The salty breeze and sea spray can wreak havoc on building materials, causing rapid corrosion, especially to steel components.
Render is often used on coastal houses to protect the substrate from the elements but staining from rusty steel beading, which is used to reinforce the edges and create attractive straight finishes, can spoil the look. Thankfully, there is a solution that stands up to the harsh coastal environment: PVC render beads. These beads offer long-lasting protection and performance, outperforming their steel counterparts for a finish that endures.
Why do coastal conditions cause such severe corrosion?
The main culprits behind the rapid corrosion of steel near the coast are moisture and salt. When these substances combine with metal, they speed up the rusting process significantly. Steel exposed to salty air corrodes up to ten times faster than it would in typical inland conditions with normal humidity(1). This makes the choice of materials for coastal construction projects crucial, as the wrong choice can lead to rapid deterioration and costly repairs.
The effects of corrosion aren’t just a cosmetic issue. While rust from steel beads can cause unattractive stains on facades, the damage goes deeper. Corrosion weakens the structural integrity of the facade, and what starts as a minor issue can evolve into a major problem, requiring significant investment to fix or replace affected materials.
What counts as coastal conditions?
Determining what qualifies as a coastal environment can be tricky. The impact of saltwater and salt air depends on a range of factors, including local geography, weather patterns, and wave heights. The more exposed an area is, the more likely it is to face harsh coastal conditions.
As a rule of thumb, any location within about 5 km of the sea is considered to be exposed to coastal conditions. Buildings within 500 metres are at even greater risk.
For a nation like the UK, which is surrounded by water, this means a significant portion of land — including many large cities — can experience these effects. Builders working in these areas need to be aware of the heightened risks and choose materials accordingly.
The best materials for coastal construction
Standards such as BS EN 13914-1:2016 advise using corrosion-resistant materials for rendering in marine environments. While marine-grade stainless steel is one option, it is often prohibitively expensive. A more cost-effective and durable choice is PVC beads.
Renderplas PVC render beads, for example, are designed specifically for harsh environments and come with a guarantee of at least 25 years of performance, or the complete lifetime of a render.
Unlike steel, PVC does not rust, making it an ideal material for use in coastal areas. It offers the same strength and reliability without the risk of corrosion, ensuring that buildings maintain their appearance and structural integrity over time. Additionally, PVC beads are easy to install and require little maintenance, saving time and money on projects, and can be manufactured from up to 100% recycled PVC to reduce a project’s carbon footprint.
A superior choice
Building in coastal areas presents unique challenges, but choosing the right materials can make all the difference. While stainless steel may seem like a solid choice, the rapid corrosion it faces in salty conditions makes it less ideal. PVC render beads, such as those offered by Renderplas, provide a robust, cost-effective alternative that ensures durability and longevity. For builders looking to protect their projects from the ravages of saltwater and salty air, PVC render beads are the superior choice.
