Building on the Coast

THE BENEFITS OF BRICK FOR COASTAL REGIONS

With over 85% of Australians living within 50km of our beautiful coastline, Australian builders have truly become experts at building modern coastal homes. After all, it’s the quintessential Australian dream - staring out at the surf over a morning coffee or having a quick stroll to the beach for a swim on a weekend morning. However, living close to the ocean can present challenges for our homes, such as brick erosion, salt attacks, water absorption, noise issues and construction site pollution.

Whether you’re dreaming of building by the coast, have bought your block of land and are researching your material choices, or you’re a professional architect or builder - read on to understand more about building with bricks by the beach.

CHOOSING THE RIGHT CLASSIFICATION OF BRICK FOR A COASTAL ENVIRONMENT

According to the National Construction Code (NCC) in Australia, the environment in which bricks must be used are classified into three groups; Exposure Grade, General Purpose and Protected. Bricks are classified based on their ability to withstand the effect of these environments. These include:

Exposure Grade

• Below the damp proof course (DPC) in areas where walls are expected to be attacked by salts on the ground
• On sea fronts where walls are exposed to attack from salt spray

General Purpose

• All areas except for Exposure Grade

Protected (PRO)

• Suitable for use above DPC, provided they are protected at the top by appropriate roofs, eaves or toppings in internal walls or coated/rendered external walls.

Severe Marine Environment

• Only EXP Bricks can be used
• Up to 1km from a surf coast
• Up to 100m from an inlet or bay

Marine Environment

• At least GP Grade bricks must be used
• Between 1km and 10km from a surf coast
• Between 100m and 1km from a non-surf coast

DURABILITY AND REDUCED MAINTENANCE

Brick is known for being a highly durable house material, with many brick houses standing for centuries with very little maintenance. Even in harsh conditions, modern coastal homes built with brick are bound to go the distance with minimal need for intervention over the decades. The durability and longevity of bricks is protective of the environment in the long-term, as reducing the likelihood or frequency of houses needing to be demolished or their materials replaced lessens construction site pollution and local environmental damage.

All bricks need (whether in a coastal setting or not) to keep them in their fantastic original condition is the occasion brush with water to clean off debris and avoid salt build-up. It’s also imperative to ensure that an adequate damp proof course (DPC) is installed, to protect the brickwork from excessive ground salts and moisture. The DPC must be installed correctly and above ground level to ensure it functions correctly.

THERMAL AND SOUND INSULATION

Oceanfront or coastal region homes can benefit greatly from the strong thermal and sound insulation properties that brick housing material provides. The heavy mass of clay that encompasses clay bricks is perfect for acoustic insulation and blocking low frequency noise (like waves crashing, traffic and weekend beachgoers). Double brick walls have the added benefit of isolating impact sounds from other rooms - perfect if guests are staying in the house.

WATER ABSORPTION

The amount of water that a brick can absorb is measured by water absorption tests under Australian and New Zealand standards. This measurement is known as the Initial Rate of Absorption (IRA) and there is no specific requirement that must be met for brick products, however the optimum range is between 0.5 and 1.5/m2/min.

When constructing brickwork buildings near the coast, it’s important to take into account the given environment, as brick’s relatively low IRA in comparison to other building materials can limit the potential for ‘salt attacks’ in coastal regions.

Salt attacks occur when salt crystals adhere to brickwork (often through seaspray or coastal salty air) and absorb into the bricks, causing brick erosion. When it rains, the salt crystals will expand within the porous surfaces of the masonry and can potentially push the outer surface of the brickwork away.

To prevent salt attack, choosing a low porosity brick or external house cladding with a smooth finish (such as our Dry-Pressed Architectural brick) will lengthen the life of the brickwork and prevent brick erosion within corrosive coastal conditions.

COASTAL HOMES USING BRICK

Home building is forever changing, with new techniques pushing the boundaries of both residential and commercial construction. But while we embrace change, sometimes it’s best to stick to the well-known and loved. The things that evoke tradition, sturdiness and strength. Materials like brick, adapted with finishes, styles and technologies that suit the modern Australian coastal lifestyle.

If you’re an architect, designer or builder and you’d like to learn more about the technical aspects of brick, you can download the PGH Technical Manual through our Downloads page. Alternatively, for personalised advice on building near the coast, submit a customer service enquiry through our website and a member of the PGH team will get back to you promptly.