NEWS Cladding testing and cost issues highlighted


A STUDY by the University of Central Lancashire (UCLan) found that the BS 8414 testing regime for combustible materials ‘omits key details […] critical’ to evaluating fire safety of the materials used; while the Housing, Communities and Local Government Committee (HCLGC) published a report that found ‘fixing fire safety defects’ in high risk residential buildings could cost up to £15bn; and the National Audit Office (NAO) released a report into the progress of removing and replacing combustible cladding, with all at risk buildings not expected to see work completed until mid 2022.


‘Crucial gaps’ in testing


The UCLan project found that the BS 8414 testing regime, ‘which allowed combustible materials to be used in the external walls of thousands of tall buildings across the UK, omits key details that are critical in evaluating the fire safety of materials used’. The ‘inadequate processes’ and ‘crucial gaps’ found came after a ‘detailed review’ of the tests and classification criteria; namely the BS 8414 tests and the BR 135 criteria. The study was carried out


by Professor Richard Hull, UCLan professor of chemistry and fire science; FPA technical director Dr Jim Glockling; Arup associate director of fire safety engineering Judith Schulz and associate director of facades Darren Kent; and A.C. Consulting Solutions Inc president Tony Crimi. Key details found to have been ‘omitted’ would ‘directly impact the risk’ of vertical fire and smoke spread over the external wall, including windows and surrounds ‘arranged above each other, along with other openings, including vents and flues’.


Although the revised standard


includes clarifications that ‘aim to improve the consistency of test results and new requirements for the formal reporting of tests’, it does ‘not address the inadequacies


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highlighted in the research’. The ‘detailed review’ was led by a ‘multidisciplinary team’ of designers, fire safety experts, regulators and researchers, who also found that the classification rules allow the temperature to rise by up to 600°C ‘within the first 15 minutes, three metres above the fire’. This is ‘where an apartment two


floors above would typically be found’, and the team stated that ‘there is no maximum threshold temperature after that 15 minute assessment window’, despite the fact that some cladding types which pass the tests reach temperatures ‘well in excess’ of this and up to 900°C ‘after 25-30 minutes’, which had been revealed by recent tests of high pressure laminate cladding by the Ministry for Housing, Communities and Local Government (MHCLG). While other temperatures are


recorded in the test protocols, ‘they are not part of the pass/ fail criteria’, and such criteria ‘are not set for factors such as falling debris, delamination, building collapse or pool fires’. The revised standard ‘states that windows, doors, balconies or ancillary penetrations such as vents, are not tested’, and the team called for a review including a ‘thorough revision’ of the BRE 135 criteria ‘to align with specific fire safety objectives’. Professor Hull commented:


‘Despite a number of measures JULY/AUGUST 2020 www.frmjournal.com


being implemented since Grenfell Tower, including the combustibles ban for residential buildings constructed after February 2019, the process by which combustible facades are permitted on tall buildings in England still does not ensure adequate fire safety. ‘With over 500,000 people


across the UK still estimated to be living in buildings with combustible cladding, it is imperative that the BS 8414 test, and the BR 135 criteria, are reviewed further. We are calling on the government to instigate an independent review of the current tests and criteria to ensure that they are robust and representative of actual buildings.’ Dr Glocking added: ‘This


research has shown that the fire safety of occupants in buildings with combustible, vented facades cannot be assured without additional, non-compulsory testing, even following the revised standard. An extension of scope to include assessment of the fire toxicity of combustible products would also seem prudent for some higher risk building types and occupant categories.’


£15bn repair costs estimated


Meanwhile, the HCLGC report estimated that fixing ‘all serious fire safety defects’ in high risk residential buildings could cost up to £15bn, with ‘some 2,000’


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