Fire safety is an important consideration when specifying decking for external spaces. Balconies and roof terraces may appear similar, but when it comes to fire regulations they are treated very differently.
Understanding how fire regulations apply to these spaces helps ensure that external flooring systems are specified correctly and remain compliant.
Balconies: A Component Approach
Fire safety for balconies takes a component approach. Every element that forms part of the balcony must meet the required classification, including the flooring system, pedestals, joists and supporting structure. Waterproof membranes are a notable exception under the regulations.
For residential buildings with a storey 11 metres or more above ground, Approved Document B requires these elements to achieve European Classification A1 or A2-s1, d0 in accordance with BS EN 13501-1:2018. The same applies to commercial buildings, for any balcony higher than 18 metres or when the balcony resides within 1 metre of a relevant boundary.
In simple terms, this means the materials used must be non-combustible (A1) or have limited combustibility (A2).
Because of this, when specifying balcony decking it is important to ensure that all components within the system have the correct fire classification, not just the visible surface material.
Roof Terraces: A System Approach
Roof terraces and podium decks are treated differently because they form part of the roof construction. In this case, fire performance is assessed using a system approach. Instead of looking at individual components, the entire roof build-up is tested together.
The relevant classification here is BROOF(t4), assessed under BS EN 13501-5, which measures how a roof system resists the spread and penetration of fire. Importantly, BROOF(t4) applies to the complete roof assembly, including the roof deck, waterproofing layer, insulation, support system and surface finish. Components cannot simply be swapped for similar alternatives unless the revised system has also been tested.
There is therefore no such thing as a standalone BROOF(t4) product, only tested roof systems.
Achieving Fire-Safe Decking in Practice
A number of materials can deliver non-combustible external flooring while still offering flexibility in design. Common options include:
Porcelain
These materials combine fire performance with durability, weather resistance and low maintenance requirements.
For roof terraces, tested BROOF(t4) build-ups are now widely available, meaning compliant systems can be specified without limiting design options. And as more manufacturers test complete roof terrace assemblies, the range of compatible systems will continue to grow.
Fire safety should always be considered early in the design process. If you're working on an outdoor project, our team can help you specify decking systems that meet fire safety requirements while supporting long-term performance.