Last edited 03 Aug 2017

Grenfell Tower fire

Grenfell-Tower-fire1.png

Contents

Overview

On 14 June 2017, a fire broke out in Grenfell Tower, a block of social housing flats in North Kensington, London occupied by between 400 and 600 people. The fire was reported shortly after midnight and rapidly engulfed the building.

The Metropolitan Police reported that 350 people were living in the Tower at the time, 255 escaped and 14 were not in the tower that night. This leaves at least 80 people who are presumed dead. The final figure may not be known until the end of 2017, but is it unlikely to change by "more than single figures".

The source of the fire is thought to have been a fridge freezer, and the unexpected speed of the fire’s spread is believed to have been contributed to by the recently-installed exterior cladding, a kind that has been cited as contributing to similar fires in high-rise buildings around the world in recent years.

The 24-storey Brutalist concrete tower block was designed in 1967 and completed in 1974. It measures 67.3 m (220 ft) high and contained 120 flats. In 2015-16, an £8.7 million refurbishment was undertaken by Rydon Ltd. Works included new new windows, aluminium composite material rainscreen cladding (ACM cladding) and heating systems and remodelling of the bottom four floors.

Rainscreen cladding systems are formed of relatively thin, pre-fabricated panels intended primarily to prevent significant amounts of water from penetrating into the main wall construction. The majority of the thermal insulation, airtightness and structural stability required by the building envelope is provided by the second, inner part of the wall construction - in this case the existing wall of the Tower.

According to Rydon, the cladding system was intended to improve the building’s thermal performance and to give it a ‘fresher, modern’ look. Installation of the cladding was undertaken by Harley Facades, but at least 8 other contractors and subcontractors were involved in aspects of the refurbishment.

The Reynobond cladding used consisted of a polyethylene core sandwiched between, and fusion bonded to, two aluminium sheets. This is a commonly-used form of ACM cladding, however, cladding panels with a mineral rather than 'plastic' core are considered to offer better fire performance.

Fire safety experts have speculated that the cladding could have created a chimney-effect in the void between itself and the original façade, which may have contributed to the speed at which the fire spread.

Several other major high-rise fires have been attributed to similar cladding systems in recent years, including; the Lakanal House fire in Camberwell (2009) [see image below], the Wooshin Golden Suites fire in Busan (2010), the Lacrosse Tower fire in Melbourne (2014), and the Marina Torch and the Address Downtown fires in Dubai (both 2015).

Lakanal House.jpg

Grenfell Tower is managed by a tenant management organisation – Kensington and Chelsea Tenant Management Organisation (KCTMO) – on behalf of Kensington and Chelsea Council. Criticism was levelled at KCTMO in the aftermath of the fire, and attention was drawn to the residents’ organisation, the Grenfell Action Group, which has repeatedly expressed fire safety concerns.

Controversy surfaced over the lack of common fire alarms, and confusion regarding the 'stay put' fire advice given to residents, which recommended that in the event of fire, they should wait in their flats for rescue, rather than attempting to escape. This is a common strategy in such buildings, as the subdivision of the overall building into fire compartments should prevent fire from spreading. In this case however, the compartmentation may have been compromised by the newly-installed cladding, which allowed fire to spread up the outside of the building.

There was also concern about the absence of a sprinkler system. Part B of the building regulations requires the installation of sprinklers in new residential blocks of more than 30m in height, but it does not require that they are retrofitted in existing blocks.

After the Lakanal House fire in 2009, a report was published which recommended the installation of sprinklers in 4,000 tower blocks across the UK. However, the government declined to bring in rules requiring the retrofitting of sprinklers, saying; "...we consider a regulatory requirement is unnecessary and disproportionate".

The British Automatic Fire Sprinkler Association said it would have cost just £138,000 to instal sprinklers to Grenfell Tower, at an average cost of £1,150 per flat. However, such work would have been disruptive, and local council leader Nick Paget-Brown suggested there was not a collective view among residents in favour of sprinklers, telling BBC's Newsnight “We are now talking retrospectively after the most enormous tragedy, but many residents felt that we needed to get on with the installation of new hot water systems, new boilers and that trying to retrofit more would delay the building and that sprinklers aren’t the answer.”

A further fire at Shepherd's Court in west London on 19 August 2016 also spread up the outside of the building, this time attributed to cladding panels made from metal, polystyrene and plywood. The fire brigade subsequently wrote to local authorities asking them to carefully consider arrangements for replacement and improvement of building facades, and to make suitable information available to fire risk assessors. Ref File:Shepherds court fire letter from london fire brigade.pdf

The Regulatory Reform (Fire Safety) Order 2005, which came into force in 2006, requires that owners of premises other than private dwellings appoint a responsible person who takes reasonable steps to reduce the risk from fire and makes sure people can safely escape if there is a fire. Fire authorities no longer issue fire certificates, but are the main agency responsible for enforcement, carrying out inspections, assessing complaints and undertaking investigations.

However, a review of the Order published by the Department for Business Innovation and Skills (BIS) in 2013, found there was considerable discretion as to how each fire authority approached its duties, and that many small businesses were not aware of their responsibilities.

Successive housing ministers have been criticised for delaying a review of fire safety regulations and Approved Document B of the building regulations for four years, following the recommendations made after the Lakanal House fire.

Updates

June 2017

On 16 June 2017, Prime Minister Theresa May announced a public inquiry would be held, while urgent safety reviews were conducted into thousands of similar tower blocks, particularly those renovated with the same cladding system. On 29 June, it was announced that the Inquiry would be led by retired Court of Appeal judge Sir Martin Moore-Bick. For more information see: Grenfell Tower Inquiry.

It was also announced that The Metropolitan Police had launched a criminal investigation, working with the Health and Safety Executive and London Fire Brigade.

On 18 June 2017, the government required social housing owners to compile lists of buildings with aluminium composite cladding panels and buildings more than 18m high by the end of 20 June 2017. Owners then had to send samples of any ACM cladding for fire tests. A letter from Melanie Dawes (File:Acm cladding checks.pdf), Permanent Secretary for the Department for Communities and Local Government (DCLG) to all local authority and housing association chief executives stated:

“Once inspections are completed and necessary work identified, DCLG will work with housing associations and local authorities to identify the most appropriate options for supporting funding.”

On 21 June 2017, Melanie Dawes wrote a similar letter to owners, landlords and managers of private residential blocks offering testing of ACM cladding, paid for by DCLG. Ref https://www.gov.uk/government/publications/safety-checks-on-private-residential-blocks

On 23 June 2017, the Police confirmed the fire started in a Hotpoint fridge freezer. They also announced that small-scale fire tests had been carried out on the Reynobond ACM cladding and Celotex insulation and both had failed. Detective Superintendent Fiona McCormack said; "The insulation was more flammable than the cladding. Tests show the insulation samples combusted soon after the test started."

On 24 June 2017, the government issued a statement from Sajid Javid MP, the secretary of state for the Department for Communities and Local Government (DCLG) regarding the cladding testing failure rate. Ref https://www.gov.uk/government/news/statement-from-the-secretary-of-state-regarding-the-cladding-testing-failure-rate

It confirmed that all the cladding samples tested at that point, that is, samples from 34 high-rise buildings in 17 local authority areas, had failed a combustibility test carried out by the Building Research Establishment (BRE). Fire and rescue services were asked to conduct fire safety inspections of those buildings to decide what remedial works might be required.

However, the statement made clear that:

...a failure in testing of the cladding does not necessarily mean that a building will have to be evacuated; the decision by Camden Council to evacuate 4 of the 5 towers on the Chalcots Estate was because the failed testing of the external cladding was compounded by multiple other fire safety failures which the fire inspection team found within the buildings.

On 26 June 2017, in a statement to the House of Commons, Sajid Javid announced the creation of an independent expert advisory panel:

It is clear that this failure must be understood; it must be rectified without delay, and the government is determined to ensure that happens. As an initial step I can inform the House today that I am establishing an independent expert advisory panel who will advise the government on any steps that should immediately be taken on fire safety. Further details of the panel including its members will be released shortly.

Ref https://www.gov.uk/government/speeches/government-response-to-the-grenfell-tower-tragedy

For more information see: Grenfell Tower independent expert advisory panel.

On 30 June 2017, the CEO’s of the Construction Industry Council, Build UK and the Construction Products Association, met with the Permanent Secretary of the Department for Communities and Local Government, together with officials from the Cabinet Office, Department for Business, Energy & Industrial Strategy, Homes and Communities Agency and the Local Government Association, to agree the establishment of a joint industry task force to enable the sector to respond to the demand for products and services to replace cladding and other fire safety equipment in the aftermath of the tragedy.

July 2017

On 14 July 2017, the BBC reported that a full review of the building regulations would be undertaken, although it is not clear when this will be officially announced, and it is likely to be complicated by the ongoing police investigation and public inquiry. Ref http://www.bbc.co.uk/news/uk-40602991

On 19 July 2017, the Local Goverment Association (LGA) called for an “urgent and immediate” review of the building regulations. Lord Porter, LGA Chairman, said; "We cannot wait for the result of the public inquiry or coroner’s report before this review is started. We have to act based on what we know now". Ref https://www.local.gov.uk/about/news/lga-calls-urgent-and-immediate-building-regulation-review

Communities Secretary Sajid Javid made an oral statement to Parliament on 20 July 2017, giving an update on the government response to the fire. He said that:

"...no more than 208 local authority and housing association residential blocks over 18 m tall have been fitted with aluminium composite material cladding. 189 of these have had cladding samples tested by the Building Research Establishment, they’ve been tested by proxy or they have already had taken their cladding down. None of them have passed the limited combustibility test." https://www.gov.uk/government/speeches/statement-on-grenfell-tower-20-july-2017.

DCMS also published an explanatory note on the large-scale testing. File:20170720 Explanatory note on large scale testing FINAL.pdf.

On 26 July 2017, site manager Michael Lockwood announced that the tower would be covered in a protective wrap to assist with ongoing forensic investigations and the eventual demolition, which he expected would begin towards the end of 2018.

On 27 July 2017, in a letter circulated to survivors of the fire, the Metropolitan Police confirmed they considered there were reasonable grounds to suspect that the Royal Borough of Kensington and Chelsea and the tenant management organisation may have committed corporate manslaughter and that they will be questioned under the Corporate Manslaughter and Corporate Homicide Act 2007.

On 28 July 2017, Communities Secretary The Rt Hon Sajid Javid MP announced an independent review of the building regulations and fire safety. See: Independent review of the building regulations and fire safety for more information.

Tests carried out by BRE on a combination of cladding and insulation systems in July and August confirmed that the systems did not comply with the Building Regulations. See ACM cladding testing by BRE for more information.



For more detailed information about the construction of Grenfell Tower and the implications for building design see: ACM cladding, and Celotex RS5000 PIR insulation.

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External references

Comments

An analysis of the Celotex RS5000 insulation located behind it raises worrying questions.

If you look at the Celotex website it states that their products are BBA (British Board of Agrement), CE (European Conformity), and BRE (Building Research Establishment) tested. Two certificate numbers are shown under the BBA insignia despite the BBA website indicating no such certificates exist. A search of the BBA certificates listed elsewhere by Celotex indicates that none were obtained for RS5000 i.e. this particular insulation has no safety certificate.

The BRE certification is used as the justification for using this material in facades over 18m in height. Reference is made to the BR135 performance specification. However this applies solely to a unique construction based on two 12.5mm skins of plasterboard on a lightweight steel frame, with another 12.5 mm of incombustible board, then the Celotex RS5000, and finally a further 12.5mm fibre cement facade panel. In other words the insulation has to be totally encapsulated in fireproof material.

Only if that construction is followed is the certification valid. The manufacturer even warns architects about this by stating that “The fire performance and classification report issued only relates to the components detailed and constructed in Fig 4. Any changes to the components listed and construction method set out in figure 4 will need to be considered by the building designer”. That’s another way of saying that if you depart from this specification - as the Grenfell Tower facade designer did - then the fire performance is invalid above 18m.

That leaves only the CE certificate. Celotex state that “CE marking confirms that our products fully comply with BS EN 13165 and that key performance characteristics have been verified through independent type testing”. One would therefore assume that since this is a product advertised for use in a fire rated construction then the fire aspects will have been tested. However when you drill down into the certificate only the thermal performance and compressive strength have been verified. The remaining ten categories simply state “No Performance Determined”. This includes Reaction to fire; Release of Dangerous Substances; Durability of reaction to fire against heat; and Durability of thermal resistance against heat. Nowhere does it tell you that polyisocyanurate releases a lethal gas in a severe fire condition. Put simply, this certificate leaves so much risk with the designer that I would have no choice but to refuse to use the product.

That then begs the question that I asked previously about the Reynobond panel. How is it possible for so many people involved in the construction of the Grenfell Tower facade to ignore the warning signs that both these materials were fundamentally unsuited for use on any high rise construction ?