Plastic Air Bricks

What Are Plastic Air Bricks?

Plastic air bricks are a modern, lightweight alternative to traditional clay air bricks. Designed to fit standard UK brickwork dimensions, they allow vital airflow into sub-floor voids, through cavity walls (when used with suitable ducting), and into other enclosed spaces. This airflow helps control moisture levels, reduce the risk of damp, and support a healthier building fabric.

Often used alongside cavity sleeves for external walls and telescopic underfloor ventilators for suspended ground floors, plastic air bricks feature a stepped front grille and integrated clips. The grille design helps deflect wind-driven rain while maintaining clear airflow, and the clips enable multiple units to be securely joined together into a single, cohesive assembly.

Available in a range of colours, such as black, terracotta, and buff, plastic air bricks seamlessly blend with different exterior finishes, complementing the aesthetic of a building while providing a functional solution for ventilation. 

Key Design Features 

• Stepped Front Grille: Many feature a unique stepped or louvred front grille design. This not only allows for consistent airflow but is also engineered to reduce the entry of wind-driven rain.
• Integral Pest & Debris Screen: The grille openings are sized to act as a barrier against larger pests (like mice) and debris (such as leaves) entering the ventilated space.
• Interlocking Capability (Integral Clips): Some designs include integral clips or connection points that allow multiple air bricks to be joined together securely, forming larger ventilation panels if required.
• Ducting Compatibility: They are often designed for easy connection with complementary components like cavity sleeves (for carrying air across an external wall cavity) or telescopic underfloor ventilators (for reaching sub-floor voids at varying depths).
• Material & Durability: Being made from UV-stabilised polypropylene or similar robust plastics, they are lightweight, resistant to rot, corrosion, and impact, offering a long service life.
• Aesthetic Versatility: Available in a range of common colours to complement or contrast with various brickwork, render, or cladding finishes.

How They Facilitate Ventilation

• Air Passage: The precisely engineered grilles on the face of the air brick allow external air to enter and internal (often damp or stale) air to exit the building void.
• Creating Cross-Flow: When installed strategically on opposing walls, or in sufficient numbers, they promote a continuous movement of air (cross-flow ventilation) through the targeted space (e.g., a sub-floor void). This constant air exchange helps to evaporate moisture, reduce humidity, and prevent the build-up of stagnant air.

Applications

• Sub-Floor Void Ventilation (Primary Use): Essential for properties with suspended timber or beam-and-block ground floors. They are installed in external walls above the Damp Proof Course (DPC) to ensure continuous airflow beneath the floor, preventing damp, condensation, and timber decay.
• Through-Cavity Wall Ventilation: When used with compatible cavity sleeves or telescopic underfloor vents, they effectively duct air from the external face, across the wall cavity, and into the sub-floor void.
• Ventilating Other Enclosed Spaces: Suitable for providing airflow to garages (especially integral ones, subject to fire regulations if applicable), utility areas, sheds, or other building voids where moisture control and air exchange are beneficial.
• Replacement of Old or Damaged Air Bricks: A common, durable, and cost-effective choice for replacing broken, inefficient, or pest-compromised clay or metal air bricks in older properties.

Benefits

• Excellent Durability & Weather Resistance: High-quality UV-stabilised plastics are resistant to cracking, fading, and degradation from sunlight and typical UK weather conditions. They will not rot, rust, or corrode like some metal or older clay alternatives.
• Lightweight for Easy Handling & Installation: Being significantly lighter than clay or concrete air bricks reduces manual handling strain and can speed up the installation process.
• Cost-Effective: Generally more affordable than traditional clay air bricks, both in terms of initial purchase price and potentially installation time.
• Effective Pest & Debris Deterrence: Most designs incorporate grilles fine enough to prevent the entry of mice and larger insects, as well as leaves and other wind-blown debris.
• Consistent Size & Quality: Modern manufacturing processes ensure each unit is dimensionally accurate and of consistent quality.
• Wide Range of Colours & Styles: Allows for better aesthetic integration with diverse building exteriors.
• System Compatibility: Often designed to work seamlessly with standard cavity sleeves, underfloor ventilation systems, and ducting.

Why Use Plastic Air Bricks? 

• Ventilation: Plastic air bricks ensure proper ventilation, complying with relevant British standards and NHBC (National House Building Council) requirements.
• Moisture Control: These bricks prevent rain penetration and moisture-related issues, maintaining building integrity.
• Energy Efficiency: By providing a free area for air circulation, they reduce the need for conventional air bricks or mechanical ventilation systems.
• Compliance: Plastic air bricks have an equivalent area marking of 6170mm², ensuring compliance with relevant building regulations.