Official tests on how some tower block claddings would perform in a fire are inadequate, a report for the Local Government Association (LGA) has warned.
Materials are being tested for the government in the wake of the 2017 Grenfell Tower fire to establish what would happen to them in a fire.
Grenfell used aluminium composite material cladding, but there are also fears about how well non-aluminium composites would resist a tower block fire.
A report for the LGA safer and stronger communities board said the government intended to test these but not “with the intention of understanding whether the above materials fail to meet the required standard.
“Instead, they are exploratory tests…we have expressed our concerns to MHCLG that this is an insufficiently robust testing regime, as the cladding panels should be tested alongside the key elements that would be found on a real building, particularly the insulation”.
The report noted that councillors had voiced fears about the effectiveness of a draft remediation plan for glass reinforced plastic fire doors, which has been led by manufacturers.
Concerns centre on this covering only the highest-risk doors and excluding buildings of fewer than 10 stories and those built from large panel systems.
The LGA was also worried by the proposed methods for prioritising door remediation as it was “reliant on test data about fire doors that does not currently exist”.
It also doubted that door manufacturers would pay enough money towards remediation costs. “We have expressed our concerns to MHCLG and directly to fire door manufacturers,” the report said.
“We envisage that government will need to supplement industry’s financial contribution with its own remediation fund, in order to ensure that the highest-risk doors are remediated.”
Work on safety issues related to buidings built using large panel systems – and establishing how many of these structures still existed – had “stalled due to a reluctance on MHCLG’s part to carry out multiple data collection exercises”.
The report noted: “The LGA is concerned that this approach will leave government unaware of the scale of the issue and creates the risk of a serious occurrence involving a large panel system building.”
A Dutch researcher had provided the LGA with a list of such buildings and it will “proactively contact local authorities asking for a simple verification of the information in the list”.
An MHCLG spokesperson said: “Nothing is more important than ensuring people are safe in their homes. We have repeatedly and consistently made clear that building owners are primarily responsible for the safety of their buildings.
“We have issued unambiguous advice to building owners 18 months ago to reinforce existing building safety requirements and tell building owners what to do to make sure their cladding system is safe. This advice was updated in December 2018.”
The ministry said its expert panel had agreed a test method for non-aluminium composites and findings from this would help to determine any further action.
Where fire doors failed tests building owners must take responsibility and review their fire risk assessments.
It said councils and housing associations had been given advice on checking the structural safety of building which use large panel systems.
The LGA report included latest MHCLG figures on social sector tower block remediation:
Work started 87
Plan in place 21
Funded through government’s cladding removal programme: 144
Funded through existing funds and litigation: 14
Latest MHCLG figures on private tower block remediation:
Work started 16
Plan in place 78
Plan in development 38
Unclear plan 32
Cladding type to be established 7