The Grenfell impact – Will the new post-Grenfell fire regulations change the way we build?
On 14th June 2017, a fire swept through the 24-storey Grenfell Tower in North Kensington. It was started by a broken fridge-freezer within a fourth-floor flat, with the flames bursting through a window and quickly spreading upwards throughout the whole building.
Within just nine minutes the fire had spread to the crown of the building, where burning debris fell and set other parts of the building on fire. The devastating blaze led to 72 people losing their lives, with countless others left injured and homeless.
The concrete block tower was built in 1974, however, it had recently been given a major £8.6 million refurbishment, which was designed by Studio E Architects and constructed by Rydon. The cladding quickly became a major focus of attention, due to the vast number of witnesses who saw the uncontrollable blaze spread rapidly across the tower’s exterior.
What cladding was used on Grenfell Tower?
One of the main aims of the refurbishment was to improve the tower’s thermal efficiency, through the addition of new external cladding. The new insulation system was manufactured using Celotex FR5000 insulation board which was attached to a timber backing. The architect’s drawings also specified the addition of a Reynobond ACM rainscreen panel, which was installed 50mm in front of the insulation.
These rainscreen cladding panels are available with a polyethylene core or a more fire-resistant honeycomb mineral core, although this is slightly more expensive. Following the fire, it soon emerged that the construction company chose the cheaper cladding option, which was already prohibited for use in high-rise buildings in some countries.
Fire safety guidance prior to the Grenfell Tower fire
According to the Department for Communities and Local Government, the cladding used on the tower was already prohibited for use on buildings above 18 metres tall. In addition, the existing fire safety legislation stated that any insulation or cladding used on buildings over 18 metres tall should be designed to meet strict combustibility regulations. However, a survey carried out by the Fire Sector Federation in 2015, found that 92% of its members believed that even this legislation was long overdue an overhaul.
In the Middle East, a series of major fires within high-rise buildings were linked to polyethylene panels, which was the same material used on the exterior of Grenfell Tower. As a result, the UAE banned the use of the material, alongside making a new rule that all components should be fire-tested with the other components, rather than on an individual basis.
Both the construction and combination of the materials can have a significant impact on the combustible properties of the architecture. The cladding and insulation system used within Grenfell Tower created a series of gaps which resulted in a chimney effect. The combination of smoke and heat forced the powerful flames upwards to the floors above.
Prior to the fire at the Grenfell Tower, the fire safety checks carried out on tower blocks across the UK appeared to have been in decline. In fact, between 2011 and 2016 the number of fire safety checks in commercial buildings and tower blocks fell by 25%.
The impact of the fire on the construction industry
The Grenfell Tower disaster has forced both the regulatory bodies and local government to review the framework relating to fire safety and combustibility. Immediately following the fire, the UK government launched an emergency fire safety review of all high-rise apartment buildings, with tests ordered for 600 blocks that were also clad in combustible aluminium-composite panels.
During these tests, a mock-up of the Grenfell Tower cladding system was built, which failed the fire safety check and was described as an ‘absolute failure’. The results led to cladding being stripped from blocks as a precautionary measure, with the high-rise safety regulations found to be unfit for purpose.
In the months following these reviews, the UK government placed a ban on the use of combustible building materials, with cross-laminated timber also limited to specific uses. This new legislation was released on 30th November 2018 and has had a huge impact on the construction industry, with the facade market in particular having to navigate the various changes in building requirements.
The legislation states that no combustible materials are permitted for use on external walls in any new or renovated building which is more than 18 metres tall. This applies to specific forms of residential housing including student accommodation, care homes, school dormitories and hospitals.
The policy states that all materials used must have a European fire rating of Class A-1 or A-2. All wood products are excluded from classification, which means the policy prohibits the use of all wooden materials in building exteriors within buildings over 18 metres tall. This also applies to engineered timber such as cross-laminated timber, which was previously viewed as a sustainable alternative to concrete or steel.
The New regulation 7(2) of the Building Regulations 2010 came into effect on 21 December 2018, with building owners and developers urgently seeking to replace dangerous cladding used within a range of external architecture designs. The new regulations also apply to balconies, solar panels and devices attached to external walls, although some components such as door frames, seals, glass and window frames are excluded from the new fire safety requirements.
The Alsecco facade systems
Fire safety has always been one of the most important factors in our designs here at alsecco. Our complete range of rainscreen and insulated facades are fully compliant with the new regulations, with an A-2 classification across each material. This means that all our cladding systems are fully compliant with the new code, even the brick designs.
This will provide you with complete design freedom, while also having the peace of mind in knowing that your materials meet the new compliance rules. Our cladding systems are available in a range of finishes including natural stone, airtec glass panels, ceramics, renders, concrete and PiPV (Photovoltaic). Through the wide array of colours and textures, it will be possible to create safe yet stylish modern tower blocks.
To find out more about our fully compliant cladding systems and how they will enhance your architecture, please contact the team today.