5 Key Considerations When Specifying Class A Decking for High-Rise Buildings
Specifying Class A decking is now a critical requirement for high-rise residential developments in the UK. Under current building regulations, buildings over 11 metres must use non-combustible materials for specified attachments, including balconies.
Choosing the right fire-rated decking system is essential not only for compliance, but also for safety, durability, and long-term performance.
In this guide, we outline five key considerations when specifying Class A decking for high-rise buildings.
What Is Class A Decking?
Class A decking refers to a non-combustible external flooring system that meets the highest fire safety standards under BS EN 13501-1.
Materials classified as:
- A1 (fully non-combustible)
- A2 (limited combustibility)
…are both suitable for use on high-rise buildings.
To comply with UK regulations, all balcony decking and external flooring systems must be constructed entirely from Class A-rated materials.
1. Choose the Right Decking Material
Selecting the right Class A decking material is key to balancing safety, performance, and design.
Although combustible materials like timber are not permitted, there are still a wide range of high-quality, non-combustible options available:
- Porcelain decking – durable, low-maintenance, and available in wood or stone finishes
- Natural stone paving – premium aesthetic with excellent longevity
- Concrete pavers – cost-effective and ideal for large-scale applications
- Fibre cement decking – modern appearance with strong performance
These materials allow you to achieve a high-end finish while remaining fully compliant with fire safety regulations.
2. Specify a Fully Non-Combustible Subframe
When specifying Class A decking systems, it’s essential to consider the entire build-up – not just the surface finish.
A compliant system must include:
- Non-combustible subframes
- Joists and pedestals
- Fixings and structural components
Even if your decking boards are Class A-rated, a combustible subframe will make the system non-compliant and unsafe.
To meet regulations for high-rise balcony decking, every component must contribute to a fully non-combustible solution.
3. Understand Fire Rating vs Fire Resistance
A common mistake when specifying decking is confusing fire-resistant materials with fire-rated (Class A) materials.
- Class A decking (A1 or A2) = non-combustible and fully compliant
- Fire-resistant materials = may slow fire spread but can still burn
For buildings over 11m, only Class A fire-rated decking is permitted.
Specifying the wrong materials can lead to:
- Failed inspections
- Project delays
- Costly remedial work
Ensuring compliance from the outset is crucial for both safety and budget control.
4. Ensure Slip-Resistant Decking Surfaces
Safety goes beyond fire performance. Slip-resistant decking is essential for external applications exposed to wet weather conditions.
To reduce the risk of slips and falls, consider:
- Textured decking surfaces
- Anti-slip coatings
- High-grip finishes
However, any slip-resistant solution must also remain non-combustible. Avoid materials such as rubber inserts that could compromise the Class A rating.
For best results, specify decking products with integrated, non-combustible slip resistance.
5. Consider Sustainability and Lifecycle Performance
Sustainable construction is an increasing priority across the UK building sector, and Class A decking materials can contribute to this.
Look for materials that are:
- Recyclable or made from recycled content
- Durable and long-lasting
- Low maintenance
Choosing sustainable non-combustible decking not only reduces environmental impact but also lowers long-term maintenance and replacement costs.
Why Class A Decking Is Essential for High-Rise Projects
Using Class A decking for balconies and terraces is not just about meeting regulations – it’s about protecting lives.
Since updates to UK building regulations, all external elements on high-rise residential buildings must minimise fire risk. Specifying non-combustible decking systems ensures:
- Safer evacuation routes
- Reduced fire spread
- Compliance with legal requirements
Failure to comply can result in enforcement action, delays, and significant financial implications.
Conclusion: Specifying Class A Decking with Confidence
When specifying Class A decking for high-rise buildings, a holistic approach is essential.
Always consider:
- The decking surface material
- A fully non-combustible subframe
- Correct fire classification (A1 or A2)
- Slip resistance
- Sustainability
By addressing these factors early in the design process, you can ensure a compliant, safe, and visually appealing decking solution.
