Concerns over post-Grenfell fire checks come as government is poised to confirm ban on combustible materials

The government has ordered a review of building safety advice amid concerns that scores of tall buildings fitted with combustible cladding and insulation may have been missed by a testing programme following the Grenfell Tower fire.

James Brokenshire, the housing secretary, told a panel of fire experts to examine whether action needed to be taken to ensure the safety of potentially thousands of residents living in towers clad in combustible materials that have not been the focus of government safety checks since the disaster claimed 72 lives in June 2017.

Brokenshire is poised later this week to confirm a ban on combustible materials, including the aluminium composite material panels and foam insulation used on Grenfell, on all new residential buildings more than 18 metres (59ft) high.

It follows the identification of 457 tall residential buildings using ACM, which is being stripped off and replaced on towers across the UK, but the ban is not expected to be retrospective.

About 160 apartment, hotel and student blocks are among high-rise properties built with sometimes different combustible materials in their rainscreen cladding systems, which have not been accounted for in the government’s targeting of buildings with ACM panels, according to industry estimates provided to the Guardian.

Rockwool, which manufactures non-combustible insulation, said an analysis of product databases relating to buildings erected or refurbished since 2013 showed 2,955 projects featured rainscreen cladding systems, of which 885 were high-rise. Seventy per cent of these are likely to use combustible foam insulation, according to separate market research seen by the Guardian.

Given that the government has identified 457 buildings over 18 metres high that have ACM cladding, this leaves about 160 buildings that are likely to feature combustible insulation set to be banned for new buildings. Some of the towers are also clad in high-pressure laminate (HPL) panels, some of which are combustible and also expected to be prohibited on high-rise homes.

“There is nothing more important than ensuring people are safe in their homes,” Brokenshire said.

“The government’s independent expert advisory panel has already published advice to building owners about other types of cladding and what action should be taken. I have asked them to review this advice to determine if additional action or guidance is required.”

The government updated advice to building owners last month, saying it was concerned about “heightened risks” linked to other external wall systems. It urged large-scale fire tests of systems. Citing HPLs, which are often made from compressed wood or paper fibre, it said owners should ensure products have been properly identified and “ensure they adequately resist the spread of fire over the wall to the standard required by current building regulations guidance”.

Confusion and uncertainty persist about building safety for residents as well as builders. Some fire brigades have found recently finished buildings clad using materials that are expected to be prohibited for future buildings, because the materials are used in conjunction with other safety measures or they have to rely on existing building regulations, which they are deemed to meet.

There has been pressure from Labour MPs who want a clearer system and have urged the government to accelerate an assessment of risks associated with non-ACM cladding, saying: “There must be no more Grenfells.”

Steve Reed, the Labour MP for Croydon North, told Brokenshire in a letter this month: “You have not yet gone far enough to guarantee public safety. We urge you to reconsider and extend the scope of the ban on flammable cladding so everyone in our country can be reassured the buildings they use are safe from fire.”

Stephen Mackenzie, a fire safety consultant, said: “The government haven’t gone far enough and haven’t tested other systems like high pressure laminate. The testing is incomplete.”

HPL panels are used at Sutton Point, a recently completed 332-apartment complex in south London. There is no suggestion the building is unsafe and the panels are labelled as fire-retardant. However, they have a European fire rating of B, which means they are considered combustible and would not be allowed on new tall residential buildings under Brokenshire’s proposed ban, which will permit only A-class materials on high-rise housing.

The building’s developer, CNM, was placed in the difficult position of fixing cladding over the past year while not knowing how building regulations would change. As a result, it said it opted to take a holistic “whole building” approach to fire safety.

The developer has installed fire and cavity barriers, sprinklers and dedicated firefighting lifts. It said the buildings’ compliance with fire regulations had been confirmed by the London Fire and Emergency Planning Authority twice since Grenfell.

“The industry is now aligned to ‘safety first’ and Sutton Point is a clear example of that approach,” a spokesperson said.

Similar panels are used at a University of Essex student accommodation complex in Southend but they are backed by the same Kingspan Kooltherm insulation foam used on Grenfell, which has a fire rating of C and is combustible.

The university said the University Square complex met building regulations when it was built and Essex fire and rescue service confirmed last year it was safe. The university said it had commissioned an independent consultant to assess the cladding system in the light of new regulations.

“The safety of our students is our priority and we have extensive safety measures in place at all our buildings,” a spokesperson said.

“This includes the highest standard of fire alarm system, fully trained security staff on-site 24 hours a day who will respond to any alarm activation within two minutes, and procedures for full simultaneous evacuation if an alarm is activated.”

The government has so far spent £400m on the removal and replacement of Grenfell-style cladding and insulation on social housing blocks.