HOW DO NEW FIRE REGULATIONS AFFECT BALCONY DESIGN?

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HOW DO NEW FIRE REGULATIONS AFFECT BALCONY DESIGN?

This article outlines the balcony fire regulations which came into effect in December 2018.

 

As we have noted in a previous blog, in the past few years there has been an undercurrent of action within the construction industry to address a need for improved fire safety on balconies. When the Grenfell disaster threw an unforgiving spotlight on the use of flammable building materials, the issue instantly became part of the national conversation. Just over a year later, the West Hampstead balcony fires brought it to the fore once again. It was only a matter of time before safety concerns gave rise to statutory measures and those changes arrived on 21 December with The Building (Amendment) Regulations 2018 (S.I. 2018/ 1230) and amended Approved Document B and Approved Document 7 Guidance.

The new regulations ban the use of combustible materials in external wall systems and balconies. From now on, developments must use materials that are A2-s1, d0 rated or Class A1 under the European classification system (Euroclass) set out in the standard BS EN 13501-1 subject to exemptions. With requirements and definitions which depart from Approved Document B2, Schedule 1 B4, the new regulations prohibit other routes to compliance that were previously acceptable, including a desk top study or a test to BS 8414 to achieve BR135 certification. An overview of the Euroclass system is provided at the end of this article.

The ban applies to buildings which have a floor above 18 metres from the ground and are used for residential purposes, including student accommodation, registered care premises, hospitals and dormitories in boarding schools. The new regulations are not retrospective – they only apply to new build construction, replacement materials within a refurbishment and projects in which an existing building’s use is being changed to one of the relevant building types e.g. an office block converted into apartments.

The government has published an impact assessment outlining the implications of the ban, including projected costs involved. From a specification perspective, the new regulations provide greater clarity and a more straightforward route to compliance. In terms of balcony specification, one of the most obvious implications is a narrowing of options for decking and flooring materials. A number of materials with elements of wood, including composite decking products, were previously compliant but are no longer permissible as they are not A2-s1, d0 rated or class A1 under the Euroclass system.

Certain materials containing only a very small amount of organic compounds (e.g. concrete, steel, stone and ceramics) are deemed to satisfy the requirements of class A1 without testing. The highest possible European class for fire retardant wood products is class B. With its A1 rating, aluminium is an obvious choice for balcony flooring. It combines fireproof performance with a wide range of other benefits, including a recognised design life of at least 60-100 years. It’s maintenance-free, corrosive-free and 100% recyclable.

Aluminium is also lightweight (1/3 of the weight of steel) yet high in load-bearing capacity. This means it requires less supporting steelwork than other materials, thereby significantly reducing costs.  It can also be easily machined to provide a slip-resistant surface.

Even before the new regulations, aluminium was an increasingly popular choice due to these multiple advantages. Now that the new law has come into effect, this versatile metal is likely to experience a huge surge in demand and it could become established as the number one choice of material for balcony decking and flooring. Neaco offers a wide range of aluminium decking profiles with specially engineered anti-slip surfaces, efficient drainage and the highest levels of fire safety. To find out more, contact our technical support team.

 

 

THE EUROPEAN CLASSIFICATION SYSTEM (EUROCLASS)

 

Many of the member countries of the European Union (EU) have adopted the harmonised Euroclass system which provides a common classification framework for building products based on their reaction-to-fire performance. Reaction properties include ease of ignition, spread of flame, evolution of smoke and toxic gases, and heat release rate of the burning material.

1) Fire classification of building products/materials

In the Euroclass system, materials are divided to seven classes on the basis of their reaction-to-fire properties: A1, A2, B, C, D, E and F.

The main properties to assign classification are non-combustibility, ignitability, flame spread, calorific value as well as the development of smoke and burning droplets. Depending on the outcome of the various properties, the product is assigned a fire classification as shown below.  

 

balcony fire regulations

 

The diagram includes additional classes for smoke development:

 s1 the structural element may emit a very limited amount of combustion gases

 s2 the structural element may emit a limited amount of combustion gases

 s3 no requirement for restricted production of combustion gases

 

 

The above diagram also includes additional classes for burning droplets

 d0 burning droplets or particles must not be emitted from the structural element

 d1 burning droplets or particles may be released in limited quantities

 d2 no requirement for restriction of burning droplets and particles

 

 

2) Performance descriptions and scenarios

The performance description and the fire scenario for each class are outlined in the below table.

Indicative performance descriptions and fire scenarios for Euroclasses.

ClassPerformance descriptionFire scenario and heat attackExamples of materials/products
A1No contribution to fireFully developed fire in a room

At least 60 kW/m2
Natural stone, concrete, bricks, ceramic, glass, steel, aluminium
A2No contribution to fireFully developed fire in a room
At least 60 kW/m2
Products similar to those of class A1, including small amounts of organic compounds
BVery limited contribution to fireSingle burning item in a room

40 kW/m2 on a limited area
Gypsum boards with different (thin) surface linings. Fire retardant wood products
CLimited contribution to fireSingle burning item in a room

40 kW/m2 on a limited area
Phenolic foam, gypsum boards with surface linings (thicker than in class B)
DAcceptable fire contribution to fireSingle burning item in a room

40 kW/m2 on a limited area
Wood products with thickness greater than or equal to10mm and density greater than or equal to 400 kg/m2 (depending on end use)
EAcceptable fire contribution to fireSmall flame attack

Flame height of 20mm
Low density fibreboard, plastic-based insulation products
FNo performance requirementsSmall flame attack

Flame height of 20mm
Examples of products not tested (no requirements)

 

 

3) Fire classification of structures

 

Construction materials and products are classified according to how they react to fire, but structures such as roofs and walls – as well as systems such as ventilation ducts and pipes – are classified based on their fire resistance. The following properties are tested and classified.

The test results are measure in terms of how many minutes the structural element resists the fire before the threshold for each criterion is exceeded.

 

balcony fire regulations