New research carried out in the wake of the Grenfell Tower fire has exposed the ‘utter inadequacy’ of the tests currently used to check the fire safety of building materials.

The Association of British Insurers (ABI) commissioned the Fire Protection Association (FPA) to test external cladding systems in experiments that more closely replicated the conditions the materials would be used in than is currently the case with standard tests.

In one experiment, the FPA created a fire with just wood - as is the normal practice for such tests - and a fire where 20% of the materials were plastic, a more realistic simulation.

The fire containing plastic had flames that extended one metre longer than the wooden fire and the temperatures involved were 100 degrees hotter.

In a second test, the FPA set fire to three columns. One was bare, the second had cladding fitted to create a void but with sealed edges and ends, the third was clad with a void, leaky sides and some ventilation at the top and bottom.

The last column - considered to be the one that most closely resembled a real-life situation - rapidly caught fire and the flames enveloped the entire column. The fire on the other two columns quickly self-extinguished because of a lack of oxygen.

In the final test, the FPA set fire to a section of wall covered in cladding that had a plastic vent installed, as would normally be the case on a building. The vent provided a route for the fire to spread rapidly.

‘The results of this important research confirm long-held concerns by many in the fire sector that the current cladding test standard requires urgent review to ensure that systems that pass are reflective of the systems that are installed and of the risks to which they are exposed,’ said Jonathan O’Neill, the managing director of the FPA.

‘We urge BSI (British Standards Institution) to urgently reconvene the group responsible for this standard to consider the results of this research and to make changes to the standard as required.’

The results of these tests have been included in the ABI’s submission to Dame Judith Hackitt’s review into Building Regulations and Fire Safety, which was established by the Government following the Grenfell Tower fire tragedy.

ABI also called for an end to the use of all but non-combustible materials in construction, and a reformed testing regime that replicates real world conditions to provide genuine evidence of how materials perform in a fire.

‘Dame Judith Hackitt’s important work post-Grenfell has already recognised the building control system is broken,’ said Huw Evans, director general of the ABI.

‘This latest research is yet more evidence that fundamental reform is needed to keep our homes and commercial premises safe from fire.

‘It is a matter of urgency that we create the right testing regime that properly replicates real world conditions and keeps pace with building innovation and modern design.’

The Government is currently consulting on the use of ‘desktop studies’ to assess the fire performance of external cladding systems after Dame Hackitt recommended in her interim report such studies be ‘significantly’ restricted.