Worcester Park

AN INVESTIGATION into the fire at the timber framed housing association block last year found that it was fitted with ‘defective’ cavity barriers that ‘contributed nothing to control of the fire’.

The fire last September destroyed a block on the estate in London, and residents were reported last October to have been ‘left at risk’ because of ‘missing or useless’ compartmentation. At that time, it had been established that there were ‘apparent flaws’ in two other buildings constructed by the same developer – Berkley Group – that would ‘allow fire to spread quickly’.

While the company responded that all the properties had been ‘independently signed off’, the housing association for The Hamptons estate amended its stay put evacuation policy after advice from London Fire Brigade (LFB). According to former resident Stephen Nobrega, the fire’s spread ‘was more or less instant. It was like paper. You would expect that the materials would contain a fire for a considerable amount of time, but it just didn’t happen’.

While there were no injuries, residents ‘believed they just about escaped in time’, with a number losing their homes. As a consequence, the development was ‘on high alert’ with 24 hour waking watch patrols, and housing association Metropolitan Thames Valley Housing (MTVH) ‘fitted smoke alarms in the electrical cupboards’ of all blocks. Two independent surveyors assessed another building on site, and found fire would ‘spread at speed’ there due to missing compartmentation.

Arnold Tarling found a ‘large gap between the fire stopping and the cladding’ which would act as a ‘chimney through which a fire will spread […] what we have here is a form of fire stopping which just won’t do its job’. Greig Adams said the breaches had ‘consequences, including a considerable increased risk to life in the event of a fire. The provision of effective fire barriers is a mandatory requirement, not an element that can be shoddily thrown together or to cut corners on’.

Previous residents had contacted Berkley Group ‘years ago’ over fire safety concerns, with one hiring an independent inspector in 2005 who discovered ‘similar problems’ with compartmentation that ‘did not meet basic fire safety requirements’. In December 2019, it was revealed that LFB had served the estate with 16 enforcement notices, after intrusive surveys found ‘a series of defects in the passive fire protection’.

This necessitated remedial work including ‘installing or improving’ cavity barriers, and correcting internal firestopping elements, MTVH having until 30 April 2021 to complete the work. The work was to be undertaken by original developer St James, which was also issued enforcement notices on some of its buildings on the estate, and MTVH pledged to rebuild the block – which had been made up of 23 shared ownership homes.

Post fire, the waking watch was accompanied by a move to simultaneous evacuation across the estate, while the communal fire alarm systems were ‘in the process of being installed’. However, Inside Housing has now reported that ‘defective’ cavity barriers ‘contributed nothing’ to slow the fire’s spread.

An investigation into Richmond House by consultancy Probyn Miers revealed flames ‘were able to rip through a 16cm cavity between the building’s main structure and cement board cladding’, and the cavity contained ‘three layers of timber battens, which provided fuel for the fire to burn behind the non-combustible cladding’.

The fire’s spread should have been slowed by cavity barriers, but those installed were defective, with the report adding: ‘In Richmond House, the cavity barriers that were fitted were defective: they were too small to close the cavity and they would have contributed nothing to control of the fire. Based on the limited number of drawings that I have seen, the defects in the cavity barrier installation appear to be the result of errors in the design.’

This meant flames were able to spread ‘almost unhindered both horizontally and vertically’ through the cavity, and on reaching the roof met a plastic board attached to battens that ‘burned readily and melted away’. There were no cavity barriers fitted to prevent spread into the roof, and so ‘there was no effective obstacle to prevent fire spreading into the roof, which there should have been’.

The report also noted that external walls were built with limited combustibility cement board with an A2 fire rating, but this was fitted to the cavity with timber battens that ‘burned fiercely’ and allowed flames to ‘spread rapidly, vertically and horizontally, inside the wall’. The cavity barriers were ‘too small and had almost no effect’, said to be because of ‘errors in the design’. Balconies were made from steel and finished with glass reinforced plastic and timber decking, which burnt.

The aforementioned issues with the roof and the plastic board allowed fire into the roof made of timber, which also burned, and while firestopping ‘may have been absent’, it ‘probably contributed little’ as the fire had already spread so far. Internal plasterboard walls were attached to timber stud walls, and resisted fire spread ‘more effectively’ than outer walls, largely preventing spread to the north east of the building ‘despite the south-west being almost completely destroyed’.

An escape staircase remained ‘largely undamaged’ as well, and many of the residents ‘are still in temporary accommodation’, having submitted a call to the government for reforms of the planned building safety bill, as the current package ‘fails to tackle the fundamental need to hold construction companies and property owners responsible for the construction failures they were responsible for’.

Their submission added: ‘We had to run for our lives in the middle of the night, in many cases carrying babies and young children, and wearing only our nightclothes. Residents opened their curtains to see a wall of flame. We all escaped the flames by moments and were lucky to come out with our lives. The requirement for cavity barriers is not new, complex or unknown.

‘It does not arise because of modern cladding materials but is a basic fire safety requirement identified within the existing building safety regime. The nature of construction is that failures can remain hidden for years and are only revealed, as with us, when there is a fire. By this time construction companies have moved on and seek to avoid or deny liability.’

They added that both Berkeley and MTVH are ‘refusing to pay compensation and have instructed commercial professional dispute lawyers to deny any liability’, while Richmond House – having been under 11m in height – would not be considered higher risk even under the new regime. The residents called for an ‘increase in scope to cover all innocent leasehold victims coupled with backing of real financial consequences that cover the costs of remediation’.

Former resident Jennifer Frame stated: ‘The attention and focus and funding has been so much on cladding, which is obviously a huge issue, it’s the most visible one but there’s so many other less visible issues that are not getting the attention they deserve. We’ve seen with our own eyes what a lack of cavity barriers and compartmentation can do to a building.’

An MTVH spokesperson said: ‘In November 2019, MTVH provided Richmond House residents with the intrusive survey report into their building from forensic architects, Probyn Miers. This was in line with our commitment to understand what happened on the night of the fire and to share information with residents. The report was discussed openly at a meeting attended by the residents and other stakeholders.

‘At the same time, independent experts also carried out assessments of the other buildings at The Hamptons owned by MTVH, and the findings of these investigations were then discussed at a series of drop-in events with residents, where the proposed remedial works were outlined. St James will be carrying out the remedial works on behalf of MTVH on the properties we own on the estate.’

The building will be rebuilt ‘in the same style of construction’, and a St James spokesperson responded: ‘A year on, St James once again extends its sincere sympathies to everyone affected by this terrible fire. As we have explained to residents, the cavity barriers contributed to the spread of the fire, although its initial cause was never identified.

‘Richmond House has since been demolished, planning consent has just been given for its replacement and construction work will proceed once the detailed design work has been completed and building regulations approval is in place. St James continues to work with MTVH, the council and all residents on The Hamptons development to make sure wider remedial works across the site are carried out properly, safely and with a minimum of disruption.’