Grenfell House Fire.

Exterior fire spread discussed by Tim Veater.


http://thefader-res.cloudinary.com/images/w_760,c_limit,f_auto,q_auto:best/GettyImages-695781690_js5kch/police-man-a-security-cordon-as-a-fire-engulfs-the-grenfell-tower-in-west-london.jpg


Now let me deal with a number of issues in relation to the external spread of fire. 

From the above photograph, taken probably less than half an hour after the fire erupted, certain features can be observed. 

The fire has already reached to the top of the building on at least two exterior elevations, setting alight the interior rooms as it progressed. With reference to the above photograph, it would appear the surface cladding on the left hand elevation, where it is claimed the fire started within a fourth floor flat, at this point has in fact burnt out, leaving fires, within virtually all the flats on that elevation.

Live video of the event can be seen here: https://www.youtube.com/watch?v=mWwNvdTqb68&t=40s



https://az-eandt-live-media.azureedge.net/e/3/c/b/d/d/e3cbdd8718bb26e95a3b8bd200a525c487fd8896.jpeg

Meanwhile, fire still rages in a diagonal line of flame on the right hand elevation, setting alight to flats as it progressed. Significantly please note how this upward movement of flame appears to be contra-indicated on the far right. I would suggest that this is because it travelled down the corner vertical rib feature, suggesting no effective fire breaks had been incorporated in the design. 

This conclusion is supported by the following image after the fire had been extinguished (below).


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Note how consistently there is evidence that fire has travelled down the vertical ribs beyond the face particularly in respect of the far right corner. Apparently in this manner fire traversed from just one side to all four! This is quite remarkable. 

Plainly, not only was the cladding highly flammable, there were no effective fire stops either vertically or laterally. Indeed the material and design of the vertical ribs appears to have facilitated the spread upwards and downwards, and significantly around the corners of the building. The damage to the four elevations is represented in the following diagram:


https://ichef.bbci.co.uk/news/660/cpsprodpb/C942/production/_96522515_grenfell_tower_fire_starting_point_624.png


From the above BBC illustration it would appear from the initial fire location on the North East corner of the building, flame spread predominantly upwards in both directions, subsequently engulfing the South and West elevations also. It is also likely that wind direction played a significant part in the flame progression.

The above diagram is supported by this image of the still smoking tower block, facing the morning sun and so revealing the western and southern elevations to left and right.



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The fire was obviously hot enough to breach any barrier provided by the windows and set fire to flat interiors that were extensively damaged. Whether there were any other factors that supported the interior fires, awaits to be seen but there are some puzzling images of intense flame whist combustible items such as cupboards remain largely undamaged. This needs to be explained particularly in relation to possible gas supply.

Apart from the basic problem of inadequate fire stops, it is clear that the cladding itself demonstrated no evidence of fire resistance. Indeed it appears to have been highly flammable. It is quite astounding that such a material was specified and/or approved for such use, if indeed it was. Only a searching investigation, including the examination and testing of remaining panels, will determine this point. 

It has been reported that the fire-resistant version would have added only £5,000 to the overall cost. In view of earlier incidents around the world and specific warnings, it is hard to view this decision as other than scandalously reckless!

The exterior cladding, consists of a 3mm composite panel - a 'sandwich' of aluminium and polythene. (See diagrams above and below) The polyethylene is flammable, the aluminium is not. In a statement issued after the disaster at the end of last week, the Department for Communities clarified the legal position as follows: 

“Cladding using a composite aluminium panel with a polyethylene core would be non-compliant with current Building Regulations guidance. This material should not be used as cladding on buildings over 18m in height.”

If this is the official government position, the question remains how it came to be used and escaped all the professional and administrative hurdles in the process?

Wikipedia states: 

"In September 2014 a building regulation notice a for the recladding work was submitted to the authority, and marked with a status of "Completed—not approved". The use of a "Building Notice" building control application is used to remove the need to submit detailed plans and proposals to a building control inspector in advance, where the works performed will be approved by the inspector during the course of their construction. Building inspector Geoff Wilkinson remarked that this type of application is "wholly inappropriate for large complex buildings and should only be used on small, simple domestic buildings"" (4)

The obvious question to be answered by any enquiry therefore is: 

• Why was the cladding specified and allowed to be used in this case?

• Did the architects specify it knowing it breached Building Regulations?

• Did the clients through their architects, seek Building Regulations approval or did it escape such oversight as a self-certification?

• Could it have happened if previous governments had not relaxed the planning/building regulations legal framework allowing developers to self-certify works of this nature?

• Or is there evidence that a cheaper material had been substituted from that specified?

The panels are made by an American firm, "Arconic". Its web page here (https://www.arconic.com/global/en/what-we-do/building-and-construction.asp) states: 

"Arconic has been helping advance innovation in building design for well over a century. We invented the look of the modern downtown, and then, from the Statue of Liberty to the US Bank Stadium—home of the Minnesota Vikings—we’ve never looked back. Arconic’s Kawneer, Reynobond and Reynolux technology can be found across skylines the world over.

"Our breakthrough technologies serve a larger purpose—high-thermal performance to meet growing demand for energy efficiency. Resiliency, to protect against hurricanes and natural disasters. And blast mitigation to protect what’s inside—all while advancing the boundaries of architectural design."

In the light of Grenfell this may be cause for some concern!

The company claims to be a very ethical one. It states: 

"Arconic is a Values-based company

Our Values guide our behavior at every level and apply across the Company on a global basis. We expect all directors, officers and employees to conduct business in compliance with our Business Conduct Policies and we survey compliance with these policies on an annual basis. The Board has adopted a number of policies to support our values and good corporate governance, which we believe are important to the success of our business and in advancing shareholder interests. Our Corporate Governance Guidelines along with our Certificate of Incorporation, By-Laws, board committee charters, Director Independence Standards, Code of Ethics for the CEO, CFO and Other Financial Professionals and Related Person Transaction Approval Policyform the foundation for the governance of Arconic."

The question to be posed is: 

• Does it do all that it realistically can to warn buyers of the limitations of its products as well as its advantages, with all the necessary precautions to be applied?

• More specifically did it do so in the case of the Grenfell Tower refurbishment?

• If it knew of inherent dangers in relation to exterior cladding and fire why did it not insist that fire retardant panel were used?
• 
  

Structure of an ACM sandwich panel. In the case of Reynobond PE, aluminum sheets' thickness is 0.5 mm (0.020 in) and overall panel thickness is either 3, 4 or 6 mm.  https://en.wikipedia.org/wiki/Grenfell_Tower_fire#/media/File:ACP_structure_-_small.png

The precise specification can be found here: http://www.arconic.com/global/en/products/product.asp?prod_id=1706&cat_id=916 (3)

The above diagram may misrepresent the material actually used on Grenfell insofar as the overall depth of the panel we are told was three (3) mm. If so the polypropylene (polythene) filling would be only two (2) mm and proportionately much thinner than that shown. 

This does raise the fundamental question: 

• why the panels were so innately flammable?

Physical Properties of Aluminium in Fire

As probably most people know, there are three basic requirements for combustion (fire oxygenation) to take place: heat, oxygen and fuel. Although plastic is flammable, aluminium isn't. Aluminium is rated AA for fire resistance. It melts at 660 degrees Centigrade - twice the temperature required to melt lead. It melts but will not burn. See below (1) Although this document (2) gives ranges of 935 to 1215 degrees F. clearly much lower. I am not a metallurgist and so unable to explain this wide divergence in physical properties but it needs to be.

In practice the compressed laminated nature of the panel would prevent the air (oxygen) getting to the interior polythene layer which in any event at just 2 mm thick, it is hard to see how it would generate so much flame and heat, without some additional physical factor involved. 

In addition, aluminium is very good at conducting heat, which would have the effect of reducing surface temperature, yet this appears to have had no mitigating effect, the fire raging white hot and emitting grey coloured smoke suggestive of the aluminium itself being consumed. This is quite extraordinary and proves the temperature of the blaze must have been in excess of 660 degrees at least.

The basic questions to be answered therefore are:

• What was the melting point of the aluminium alloy panel actually used?

• How was it possible given the laminated construction denying air access to the flammable polythene core, was such an intense fire allowed to take hold?

• Given the fact that aluminium melts but does not burn and only a relatively thin (2 mm) of inflammable plastic was available to support combustion, how can the intense heat, white-hot flame, white smoke and incredible speed of spread, be explained?

• Was the aluminium material used for these specific panels altered in any way to support combustion? 

All this information should already be available to investigators if urgent tests have been carried out under controlled conditions, as of course they should have been.

Architects for the scheme

The refurbishing scheme was supervised by Studio E Architects, based at http://www.studioe.co.uk/?page_id=997 As such this firm would carry the ultimate responsibility for the specification and standard of work.

The schemes in which the firm has been involved are listed on its web site. They appear to be predominantly social and educational, many benefiting from Government policy and grants. A photograph of the Grenfell building on completion and prior to the fire, is still featured on the firms web page (as of 21.6.2017)

Over 120 clients are listed including many related to central and local government, particularly in the capital.

Directors: 


Andrzej Kuszell
DIRECTOR  

RIBA, DipArch

Andrzej Kuszell is a Founding Director of Studio E Architects. His main drive has been to develop and raise the practice’s architectural profile with a particular focus in education and sports/leisure design. With a passion for surpassing his clients’ expectations, he has become a recognized innovator in both sectors with results founded on a commitment to holistic sustainability, collaborative teamwork and a recognition that every project is special.

Responsible for a succession of award winning projects, these have included a range of new buildings at Haileybury College, the aspirational Leisure Centre for the American Community School in Cobham, the green exemplar Larmenier and Sacred Heart Primary School and the City of London Academy, Southwark which won the 2006 Prime Minister’s Better Public Building Award. In the last 6 years Andrzej has taken the lead in the design of five new Academies, two new Primary Schools as well as new International Schools in the Middle East. These projects included the City Academy, Hackney which won the BCSE Best Academy Award as well as the recently completed Kensington Aldridge Academy. In the same period the practice has twice won the BCSE School Architect of the Year Award.

David Lloyd Jones
DIRECTOR

FRSA, RIBA, AA DIPL

David is a Founding Director of Studio E Architects. An acknowledged expert and innovator in energy conscious and sustainable architecture he is responsible for a body of research work and publications that have informed Studio E Architects projects across the board. He has led on a sequence of award winning sustainable projects across a range of sectors. These have included Doxford International Solar Office, the Beaufort Zero Emissions Building, Grange Park Opera House and Townley Grammar School for Girls. Recent work has extended to master planning of the City of London Freemen’s School, the refurbishment of Highgrove Pool, designs for a new sports pavilion at Hackney Marshes and proposals for a new Arts and Crafts Institute in Pakistan. He overviews the practice’s QMS and drives the practice’s policies for high achievement in sound, energy conscious environmental design

GRENFELL TOWER – STUDIO E ARCHITECTS STATEMENT

15th June 2017

We are deeply shocked and distressed over news of the devastating fire at Grenfell Tower. Our thoughts are with those that have been affected by this tragic incident, together with all of their relatives and friends. It would be inappropriate for us to comment or speculate on events on Wednesday morning. We will be available to assist the relevant authorities as and when we are required. Our website was temporarily shut down yesterday as a result of the number of requests received.

In contrast an earlier happier story: 

"HRH THE DUCHESS OF CAMBRIDGE OPENS KENSINGTON ACADEMY AND LEISURE CENTRE

"April 22, 2016

"Transformational new school and leisure centre receive Royal stamp of approval!

"On Monday 19th January 2015 Kensington Aldridge Academy, together with the Kensington Leisure Centre, received a Royal Opening. A special moment for this corner of North Kensington after 3 years of design and construction. Studio E Architects were the master plan lead for the entire project and architects for the Academy."

The critical questions that presumably have been posed of the architects will have been:

• Did you specify the materials and fixing method of the external cladding in particular?

• Did you supervise its installation and sign off on the work?

• Were you satisfied that in all respects the work was completed in accordance with the specification?

• As respects to the interior upgrading, did you make any recommendations to the clients (the Royal Borough of Kensington or Tenant Management Organisation) on matters of fire or general safety, and if so were they all adopted?

• On completion of the works did you have any further dealings with the clients with regard to the building specifically regarding tenants representations on safety or the satisfactory nature of the works and if so what?

Main Contractor

The firm primarily responsible for carrying out the work was Rydans Construction based in Essex. Their  web site is here: http://www.rydon.co.uk/who-we-are 

It states: 

"From our beginnings in 1978, Rydon has grown into a multi-faceted company, employing over 750 people.Rydon delivers quality solutions in the built environment for education, housing and healthcare to shape and advance people’s lives."

Beside much other work and clients we are informed that: 

"Rydon has been working with the MoD for several years as a partner on the Aspire Defence Capital Works through the Allenby/Connaught framework, the largest infrastructure Private Finance Initiative project ever let by the Ministry of Defence.

"Our role has been to support Aspire Defence in the modernisation and reprovision of a significant number of military facilities around Salisbury Plain.

"To date, Rydon has won in excess of £50m of work across over 25 projects through the framework, all of which have been delivered on live operational military bases."

A chosen contractor for works is not responsible for the design of the scheme, only the competent implementation of it. 

The question for the main contractor therefore must be:

• Did you carry out the works in complete accordance with the plans and specification or did you alter any of them in respect of either the materials used or the way in which they were applied? 

• Did you at any stage have any reservations concerning these or make any representations concerning any matters that impinged on safety and particularly fire safety?

Cladding Contractors

The actual cladding work was carried by Harley Facades Ltd. The company's web site is here: http://www.harleyfacades.co.uk/ This element of the refurbishment was contracted for £2.3 m. 

The web site states:

"Harley Facades Ltd provides a comprehensive design and construction package for building envelopes including; curtain walling, windows, doors, structural glazing, and rainscreen cladding systems. Incorporating curtain walling and rainscreen into your concept design, can create a unique and cost effective solution for your building. Curtain walling and rainscreen is suitable for both new build and refurbishment projects. Harley Facades Limited has successfully undertaken projects throughout the UK involving curtain walling and rainscreen."

"Owner and Managing Director, Ray Bailey, formed the original Harley business in 1996.  With a move to it's own brand new purpose built offices in December 2003, Harley had now become well established as one of the leaders in the field of designing and constructing complete building envelopes. A further development came with the formation of Harley Facades Ltd, a business to focus on the specialist refurbishment market including high rise residential tower blocks."

GRENFELL TOWER FIRE STATEMENT FROM HARLEY FACADES LTD

"Harley Facades Limited completed the refurbishment work to Grenfell Tower.  This included the installation of exterior cladding. The Aluminium Composite Material (ACM) panels are a commonly used product in the refurbishment industry.  Harley Facades Limited do not manufacture these panels.

"Commenting on the fire, Ray Bailey, Managing Director at Harley Facades Limited said:

“This is an incredibly tragic incident.  Our thoughts are with the residents and their families who have suffered such a personal loss.  We will fully support and cooperate with the investigations into this fire.  There will be many questions about this whole incident and so you will appreciate that it would not be appropriate for us to comment or for others to speculate on any aspect of fire or it causes in advance of these inquiries.   At this time, we are not aware of any link between the fire and the exterior cladding to the tower.”

Ventilation Contractor

Apparently ventilation works were carried out. This has a baring on the disaster because the objective is to provide sufficient ventilation in case of fire to at least keep the access/escape stairway free of smoke. I am not party to what work was carried out not how far the ventilation secured this objective. All we have are numerous witness statements to the effect that the common areas and staircase was in fact with smoke and fume. 

Apparently Witt UK was chosen for this part of the refurbishment. On its web site here, http://wittukgroup.co.uk/fan-systems/ which it is claimed was taken down immediately after the event, it states:

"Fan Systems was founded in 1950, and is an acknowledged leader in the manufacture of high quality industrial fans, with units operating across a diverse range of process applications throughout the world.

"Fan Systems became part of the WITT UK Group in 1993, and acquired Alldays Peacock in 2006, adding high pressure blowers and gas boosters to complement its extensive fan range.

"Now operating from an exceptional new site in Yorkshire, and with additional world wide manufacturing capability, Fan Systems Group has one of the most advanced fan production facilities."

Question:

• As a specialist area, the design brief came from where and who approved it?

• Did the ventilation system work as intended, was the design defective or did it fail in some other manner?

Other specialist firms were employed to deal with the up-grading of electrical and other services inside the block that may have had implications on the way the incident spread and was alarmed but these are not touched on in this article. Readers are also referred to earlier articles on the subject on this blog. 



REFERENCES

1.  Extract from: http://www.alfed.org.uk/files/Fact%20sheets/11-aluminium-and-fire.pdf

"Aluminium in a Fire If aluminium is involved in a fire and the temperature rises to above its melting point, the metal begins to melt. The melting point of a metal, like its density, strength, or corrosion resistance, is a characteristic which can be measured and used to design the most effective component for any particular application. The thermal conductivity of aluminium is around four times that of steel and its specific heat twice that of steel. This means that heat is conducted away faster and a greater heat input is necessary to bring the same mass of aluminium to a given temperature, compared with steel. Where an aluminium structure is exposed to the heat of a fire, the relatively high thermal conductivity enables the heat to be rapidly conducted away from the exposed area. This helps to reduce hot spots where significant localised property loss could occur, so extending the serviceability period. It will, however, cause the temperature to rise elsewhere. The extent of dissipation of heat elsewhere in the structure will depend on the degree of thermal insulation provided to the aluminium elsewhere in the structure, necessary to provide fire protection in that area.

Relectivity of aluminium is 80% to 90%, compared with 5% for painted steel and 25% for stainless steel. This is of considerable benefit and will assist in prolonging endurance of an aluminium structure in a fire. The attached photograph is a good example of the behaviour of aluminium in the massive form in a fire. A car, with aluminium alloy wheels, was caught in a forest fire that swept over the car and moved on. Afterwards it was found that the aluminium wheels had melted, molten aluminium had run off and collected in a pool of metal which solidified as the fire moved on and the temperature fell. The aluminium had not burnt. "

"Aluminium alloy components are widely used in building as cladding and roofing materials, windows and doors. As defined by BS 476: Part 4 and the 1974 SOLAS Convention (as amended) aluminium alloys are ‘non-combustible’ and also provide Class 1 surface spread of flame to BS 476: Part 7. In addition, BS 476: Part 3 covers external fire exposure roof tests and the classifications laid down in the standard range from AA to DD. The first letter refers to the fire penetration performance and the second letter to the surface spread of flame. Aluminium and its alloys are rated AA, the highest possible under this classification system. Materials are also tested for fire propagation performance to BS 476: Part 6 (1989) and coating systems are taken into account. Aluminium achieves excellent ratings under this Standard."

SEE ALSO: http://www.alfed.org.uk/files/Fact%20sheets/11-aluminium-and-fire.pdf

2.  https://www.unitedaluminum.com/chemical-composition-and-properties-of-aluminum-alloys/

3.  http://www.arconic.com/global/en/products/product.asp?prod_id=1706&cat_id=916



4.  https://en.wikipedia.org/wiki/Grenfell_Tower_fire