Archive for March, 2012

Unheeded Fire Hazards in New Energy Efficient Buildings !!

2012-03-29:  The relentless pressure, within the European Union (EU), to bring a greater measure of stability to imported energy supplies … to reduce our overall use of energy … to be far more efficient in the ways we consume those lesser amounts of energy … to find cleaner sources of energy to replace oil, gas, and especially coal … to comply with ambitious targets on climate change mitigation … are all pointing in one direction with regard to design and construction.  We are forced to super-insulate new buildings !

Without many people realizing it, however, we change how fire behaves in a highly insulated building … especially when insulation materials are part of the interior finishes, not carefully buried within the construction.  [Even the old Building Bye-Laws in Dublin City permitted a cavity in a masonry wall up to 150mm wide !]   And, as usual, Building and Fire Regulations are slow to catch up with these important architectural developments.

Let me show you an example of a basement car park in a new hospital (which shall remain nameless !) … where a serious ‘fire’ problem has been festering since it was opened, and occupied, a few years ago.

This hospital could be anywhere in Europe …

Colour photograph showing the basement car park in a hospital. Click this photograph, and the photographs below, to enlarge.

Colour photograph showing the basement car park in a hospital. Click this photograph, and the photographs below, to enlarge.

The ceiling height in this car park is low … approximately 2 metres above floor level.  The ceiling comprises a 6mm off-white calcium silicate board of limited combustibility (for the techies out there – this board is not ‘incombustible’, and it is not ‘non-combustible’) … above which is a 40mm rigid phenolic thermal insulation board … all fixed to the underside of a concrete floor slab.

This phenolic insulation board is very efficient … and during the normal course of events, its job is to stop the loss of heat from the hospital wards and other areas above.  A cold concrete floor is also very uncomfortable for people, i.e. hospital staff, having to walk around on it for long periods.

Because the insulation board is efficient, and it is fixed to the underside of the floor slab … in a fire situation, let’s say that a fire starts in a car … the heat from that fire will be reflected by the insulation board back downwards.  The result:  the fire will be encouraged to spread much more quickly to neighbouring vehicles.  And so, in a very short time, we will have a much larger fire … and a much more intense fire … which will be far more difficult to control and extinguish, when the fire services eventually arrive on the scene.

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There are a Number of Twists in This Story …

     1.  For all sorts of normal reasons, there are service penetration openings in the car park ceiling shown above (some small and some large), especially in a hospital which is highly serviced … the overall approach to fire and smoke sealing in this new building is not the best … and workmanship is poor …

… which, together, all mean that it will be easy for fire and smoke to spread upwards into the hospital wards and other areas … in the event of a fire emergency.

In a hospital, not everybody is alert and mobile.  It will be difficult to evacuate some people … and it will be nearly impossible, because of their health condition, to evacuate others.  In order for a fire engineering strategy of horizontal evacuation to a ‘safer’ part of the same building to be successfully put into effect during an emergency … it is imperativethat the level of passive protection from fire and smoke provided is high … much higher, here, than in the case of an average office building, for example.  AND … it is criticalthat this high level of protection from fire and smoke is reliable.

In this new hospital building … the photographic evidence clearly shows that both of these criteria have not been met.

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     2.  Another twist in the story concerns the rigid phenolic thermal insulation board used in the car park ceiling … which, as the evidence also shows, is exposed to direct view in many places …

In a short, brochure-type document produced by the European Phenolic Foam Association (EPFA): ‘Phenolic Foam Insulation – The Ultimate Insulation System for the Construction & Building Services Industry’, the following is stated with regard to the fire performance of this material …

‘ Toxic gas emission from phenolic foam is generally limited to carbon dioxide and carbon monoxide with very low levels of other gases.’

However, in a report produced by the National Research Council of Canada: ‘Toxicity and Smoke Aspects of Foamed Plastic Insulation – An Annotated Bibliography’ … the following abstracts can be found …

  • Toxicity of Off-Gases from Phenolic Rigid Foam

‘ A reference sample of phenolic rigid foam was evaluated for toxicity of off-gases, using various test conditions in the NASA-USF-PSC toxicity screening test method.  Test results show that the response of this material to the various test conditions is similar to that exhibited by the majority of other materials previously evaluated by this method.  That is, animal response times generally decreased with increasing fixed temperature, and with increasing airflow rate under rising temperature conditions.  The authors suggest that formaldehyde is one of the toxicants present although the amount of CO produced at 600°C or higher was enough to be lethal by itself.

  • Toxicity of Off-Gases from Thermal Insulation

‘ Toxicity test data on the off-gases from various thermal insulation materials are presented in this paper.  Under rising temperature without forced airflow test conditions, phenolic foams exhibited the shortest times to death, while polyisocyanurate, polyurethane and polystyrene foams exhibited the longest times to death.  The introduction of airflow significantly reduced time to death, apparently due to a higher degree of oxidation and more rapid delivery of toxicants.  The authors conclude that under the particular test conditions, plastic thermal insulations appear to exhibit less toxicity than cellulosic board and cellulose insulation, with polyimide and phenolic foams being the exceptions.

  • Relative Flammability and Toxicity of Thermal Insulation

‘ Relative flammability and relative toxicity data are presented for 30 samples of thermal insulation materials.  There appears to be no inherent, necessary compromise between flammability and toxicity in the selection of materials.  Cellulosic and plastics insulations appear to represent significantly different combinations of flammability and toxicity hazards, and require different approaches when planning and designing applications.  Polyurethane foam appeared to be significantly less toxic and slightly less flammable than wood and other cellulosic materials.  Polyisocyanurate foam seemed to be more toxic than polyurethane foam but still less toxic than the cellulosic materials.  Polystyrene foam exhibited the longest time to death while phenolic foam showed the second shortest time to death among the group of rigid foams evaluated.

  • Carbon Monoxide Production from Overheated Thermal Insulation Materials

‘ Carbon monoxide yields were obtained for selected thermal insulation materials.  The data are presented and discussed in this paper.  Among the rigid foamed plastics, phenolic gave the highest yield of CO under a rising temperature and no airflow test conditions.  Polyurethane foams based on propoxylated aromatic amino polyol appeared to produce less CO than polyurethane foams based on propoxylated trimethylolpropane polyol.  Under fixed temperatures of 800°C without airflow test conditions, similar results were obtained for the rigid foamed plastics.’

  • Toxicity of Pyrolysis Gases from Phenolic and Isocyanurate Rigid Foams

‘ Special reference samples of phenolic and isocyanurate rigid foams were evaluated for toxicity of pyrolysis gases, using 6 different test conditions of the USF toxicity screening test methods.  Under rising temperature conditions, phenolic foam appeared to be consistently more toxic than the isocyanurate foam.  CO level appears to be the factor, which is twice as high from the phenolic foam.  The temperatures corresponding to the times to death indicate that the toxicants were evolved below 500°C for phenolic and below 640°C for isocyanurate.  These are in agreement with that of the University of Pittsburgh (UP) data.  At a fixed temperature of 800°C, there appeared to be no difference in toxicity between the phenolic and isocyanurate foams, although the former tended to produce more carbon monoxide.’

  • Toxicity of Pyrolysis Gases from Phenolic, Isocyanurate and Polystyrene Rigid Foam Insulation

‘ Samples of phenolic, isocyanurate, and polystyrene rigid foam insulation were evaluated for toxicity of pyrolysis gases, using four different test conditions of the toxicity screening test method developed at the University of San Francisco.  The test conditions were 200 to 800°C rising temperature and 800°C fixed temperature, each without forced airflow and with 1 L/min airflow.  On the average over these four particular test conditions, phenolic foam appeared to exhibit the greatest toxicity and polystyrene foam appeared to exhibit the least toxicity.

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As already discussed in an  earlier post , dated 2011-01-13 … we know that Carbon Monoxide (CO) is an odourless, colourless and toxic gas … and because it is impossible to see, taste or smell the toxic fumes, CO can kill before you are aware it is there.

So … it will be easy for Fire, Visible Smoke and Carbon Monoxide to spread upwards into the hospital wards and other areas of this building … in the event of a fire emergency.

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This Hospital’s ‘Fire’ Problem & Its Solution

The ‘fire’ problem in this hospital has been allowed to fester for a number of years because the issues shown in the photographs above are either inadequately addressed … or not addressed at all … in Ireland’s Technical Guidance Document (TGD) B … a document which is intended merely to present some supporting guidance for operating Part B: ‘Fire Safety’, in the 2nd Schedule of the Building Regulations.

Unfortunately, all parties directly responsible for this hospital debacle are under the very mistaken impression that the guidance in Technical Guidance Document B is prescriptive regulation.  This is a major error !   Furthermore … TGD B is fundamentally flawed … and it is particularly inadequate when the building type is a health facility.

To Correct This ‘Fire’ Problem … a Fire Suppression System should immediately be installed in the basement car park.  At the same time, if not before … ALL Service Penetration Openings in the concrete floor slab should be properly sealed so that, during a fire incident, the passage of fire and smoke and CO into building spaces above the slab will be prevented.  And … the quality of workmanship, on site, must be high !

An appropriate number of Carbon Monoxide Detectors should be installed in the hospital wards and other areas above the concrete floor slab.

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The ‘Institutional’ Problem

The procedure of having to submit so-called Compliance Reports with applications for Fire Safety Certificates, in Ireland, only confirms … and reinforces … the very mistaken impression in everybody’s minds that the guidance in Technical Guidance Document B is prescriptive regulation.

In the case of a different hospital … let me give you an example of a text contained in one such Compliance Report … submitted to an Irish Local Authority, sometime during 2004 …

Single Steps at Final Exit Doors

It is noted that Clause 1.4.3.4 of TGD-B is ambiguous vis-à-vis steps located on the line of final exit doors, i.e. as opposed to a condition where there is a step beyond the line of a door.  Accordingly, it is reasonable and appropriate to make reference to the current England and Wales Approved Document B (2000 Edition) for guidance on this issue in so far as Technical Guidance Document B is based on an early draft of the Approved Document.  It is noted that the UK AD-B in Clauses 6.15 and 6.21 specifically allow single steps at final exits provided they are located on the line of the doorway in question.  Furthermore, the recently issued Northern Ireland Technical Bulletin E (1994) also allows such steps, subject to the riser not exceeding 180mm.  On the basis of the foregoing, single steps are considered acceptable at the final exit doors subject to the riser not exceeding 180mm and the step being located on the line of the door.

This is mindless, incompetent nonsense … and it was accepted by the Local Authority.

How often, anymore, does anybody encounter a step … 180mm high, or of any height … at the front entrance to a new building ?   Building designers have finally understood the message that new buildings must be accessible-for-all … and a single step, in any situation, is a trip or a fall accident waiting to happen.  Now imagine the situation where people are attempting to evacuate an average office building, for example, during a fire emergency … and they encounter a single step at the final fire exit !?!   Now really stretch your imagination … and imagine where people are trying to evacuate a hospital !!??!!

FUBAR !!

The System is not only entirely dysfunctional … it is corrupt !

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END

 

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‘Fire-Induced Progressive Collapse’ – A Term Born To Confuse ?

2012-03-26:  Let me lay out the problem this way … recently, after further developing and refining the definition of the term …

‘ The sequential growth and intensification of structural deformation and displacement, beyond fire engineering design parameters, and the eventual failure of elements of construction in a building – during a fire and the ‘cooling phase’ afterwards – which, if unchecked, will result in disproportionate damage, and may lead to total building collapse ‘

… our attention, in CIB W14’s Research Working Group IV, automatically turned towards the term itself.  It didn’t sound right … it didn’t look right … and a lot of people in North America are still completely confused.

Was there anything we could do to clarify the situation ?

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BACKGROUND

The long delay in incorporating the Recommendations of the following 2 Reports …

  • NIST (National Institute of Standards and Technology).  September 2005.  Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report on the Collapse of the World Trade Center Towers.  NIST NCSTAR 1.  Gaithersburg, MD, USA.

and

  • NIST (National Institute of Standards and Technology).  August 2008.  Federal Building and Fire Safety Investigation of the World Trade Center Disaster: Final Report on the Collapse of World Trade Center Building 7.  NIST NCSTAR 1A.  Gaithersburg, MD, USA.

… into building and fire codes/regulations, standards and administrative provisions at international, regional and national levels … can partly be explained by institutional inertia and the stubborn resistance of vested interests in the construction sector.  To be fair, however, although both NIST Reports made extensive reference to the term ‘Fire-Induced Progressive Collapse’ … the structural concept was not defined, or elaborated, in either document.  This was not really a task for NIST.

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WHO IS CONFUSED ?

Since the publication of the 2005 NIST Report above, there has been much confusion about the term ‘Fire-Induced Progressive Collapse’.

Refer, for example, to the Introduction – Paragraph 1.1 on Page 1 – from NIST Document: ‘Best Practices for Reducing the Potential for Progressive Collapse in Buildings’ (NISTIR 7396 – February 2007) … where a lot of people, who should know better, really screwed up … and got it so wrong …

” The term ‘progressive collapse’ has been used to describe the spread of an initial local failure in a manner analogous to a chain reaction that leads to partial or total collapse of a building.  The underlying characteristic of progressive collapse is that the final state of failure is disproportionately greater than the failure that initiated the collapse.  ASCE Standard 7-05 defines progressive collapse as ‘the spread of an initial local failure from element to element resulting, eventually, in the collapse of an entire structure or a disproportionately large part of it’ (ASCE 2005).  The disproportionality refers to the situation in which failure of one member causes a major collapse, with a magnitude disproportionate to the initial event. Thus, ‘progressive collapse’ is an incremental type of failure wherein the total damage is out of proportion to the initial cause.  In some countries, the term ‘disproportionate collapse’ is used to describe this type of failure.

Based on the above description, it is proposed that the professional community adopt the following definition, which is based largely on ASCE 7-05:

progressive collapse – the spread of local damage, from an initiating event, from element to element resulting, eventually, in the collapse of an entire structure or a disproportionately large part of it; also known as disproportionate collapse.

The concept of progressive collapse can be illustrated by the famous 1968 collapse of the Ronan Point apartment building (Fig. 1-1). “

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Colour photograph showing World Trade Center Building No. 7 in ruins after 9-11 in New York City ... when Fire-Induced Progressive Damage led to Disproportionate Damage, and finally to total building failure ... a Collapse Level Event (CLE). Click to enlarge.

Colour photograph showing World Trade Center Building No. 7 in ruins after 9-11 in New York City ... when Fire-Induced Progressive Damage led to Disproportionate Damage, and finally to total building failure ... a Collapse Level Event (CLE). Click to enlarge.

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WE NOW KNOW

Fire-Induced Progressive Damage in Buildings is distinguished from Disproportionate Damage – a related but different structural concept – by the mode of damage initiation, not the final condition of building failure.  Until this phenomenon is properly understood, and unless it is impeded, or resisted, by building design … Fire-Induced Progressive Damage will result in Disproportionate Damage … and may lead to a Collapse Level Event (CLE), which is entirely unacceptable to the general population of any community or society.

So … if unchecked, Fire-Induced Progressive Damage will lead to Disproportionate Damage.

BUT … while it may happen … which it did, when WTC Building 7 failed completely at approximately 17.21 hrs (local time) on the afternoon of 11 September 2001 in New York City … it is not necessarily always the case that Fire-Induced Progressive Damage and Disproportionate Damage will lead to Total Collapse.

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OUR SOLUTION

In order to avoid the wide confusion which the term ‘Fire-Induced Progressive Collapse’ is continuing to cause at international level … the preferred term is now Fire-Induced Progressive Damage.

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Stop Press ! … ISO 21542 on Accessibility-for-All Published !!

2012-03-25:  No news about this momentous development, yet, on the International Design and Disability Networks … (why is that ? – are they all asleep out there ?) … but International Standard  ISO 21542: ‘Building Construction – Accessibility and Usability of the Built Environment’  was finally published by the International Standards Organization (ISO) in December 2011 !   Even ISO, and national standards organizations, have been slow with an official notification.

This International Standard now provides building users, architects, designers, engineers, builders, building owners and managers, manufacturers, policy makers and legislators with the requirements and recommendations to create a Sustainable Built Environment which is Accessible.

The First Edition of ISO 21542, dated 2011-12-15, represents an agreement reached by strong consensus between different countries all over the world … an agreement patiently constructed and pieced together by a small, dedicated international group of Accessibility Experts.  As one of those experts, I am tremendously relieved that this main task has been accomplished … but the process must continue … there are still errors in the document … and the fire safety texts must be expanded.

This is also an agreement which signals that uniform implementation of the main provisions (accessibility-related) in the United Nations Convention on the Rights of Persons with Disabilities (UN CRPD) can commence across the globe, not just in the developed economic regions.

The purpose of this International Standard is to define how the built environment … in particular, public buildings … should be designed, constructed and managed to enable people to approach, enter, use, egress from and evacuate a building independently, in an equitable and dignified manner and to the greatest extent possible.

Colour image showing an Accessible Fire Evacuation Route Sign. From now on, Building Users should expect that these routes will be Accessible-for-All, throughout their full extent, until they reach a Place of Safety which is remote from the Building. Otherwise, they will be able to find accommodation in a suitable Area of Rescue Assistance along the route. Click to enlarge.

Colour image showing an Accessible Fire Evacuation Route Sign. From now on, Building Users should expect that these routes will be Accessible-for-All, throughout their full extent, until they reach a Place of Safety which is remote from the Building. Otherwise, they will be able to find accommodation in a suitable Area of Rescue Assistance along the route. Click to enlarge.

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A new international understanding of ‘Building Accessibility’ is hereby established … ‘Access’ (approach, entry and use) can no longer be divorced from ‘Egress’ (in the normal course of events) and ‘Evacuation’ (in the event of an emergency).

The concept of ‘Access’, in isolation, and the role of the ‘Access Consultant’ are, therefore, outdated and obsolete !   And use of the word ‘Escape’, in any context, is to be firmly and rigorously discouraged !!

The intention of this International Standard is to meet the needs of the majority of people.  This goal is achieved by agreement on minimum standards of accessibility and usability which are generally accepted to accommodate diversities of age and the human condition.

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In future … proper emphasis must be placed on Real and Effective Implementation of Accessibility-for-All in the built environment … to meet the needs of real people in all of our communities.

In the past … too many scarce human resources have been diverted into pointless discussions and arguments about accessibility design philosophies.  And, particularly in Europe, we have been far too fond of ‘talk’, instead of ‘action’ !   No more !!

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ISO 21542 : 2011  applies to new and existing buildings.

IF this Standard’s requirements and recommendations are taken into consideration during the earliest stages of New Building Design … the costs of providing satisfactory accessibility and usability in a building will be minimal.

Yes, there are problems with improving the accessibility performance of Existing Buildings … just as there are problems, for example, with improving their energy performance.  However … creativity, design flexibility, and an in-depth understanding of the principles of Accessibility-for-All … will ensure that the functional requirements of this Standard are properly met.

Mindful of the  1964 Venice Charter  and other similar international instruments … accessibility must also be facilitated in Existing Buildings of Historical, Architectural and Cultural Importance.  In such cases, it will be necessary for national authorities having jurisdiction to allow some relaxation of the requirements in this International Standard … as well as to proactively recommend appropriate alternative accessibility measures.

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This new approach to Accessibility-for-All in the Built Environment … as set down in ISO 21542 … was directly informed by Preamble Paragraph (g) and Articles 9, 10 and 11 of the United Nations Convention on the Rights of Persons with Disabilities (UN CRPD).

At the time of writing … the UN CRPD has been ratified by the European Union (EU) and 109 Other Countries.

An Important Note for Parties to the Convention which is entirely outside the scope of ISO 21542, and standardization generally … but very relevant to the implementation, for example, of Article 11 at national level in the ratifying Countries and EU Member States …

UN CRPD  Article 12 – Equal Recognition Before The Law

1.   States Parties reaffirm that persons with disabilities have the right to recognition everywhere as persons before the law.

2.   States Parties shall recognize that persons with disabilities enjoy legal capacity on an equal basis with others in all aspects of life.

3.   States Parties shall take appropriate measures to provide access by persons with disabilities to the support they may require in exercising their legal capacity.

4.   States Parties shall ensure that all measures that relate to the exercise of legal capacity provide for appropriate and effective safeguards to prevent abuse in accordance with international human rights law.  Such safeguards shall ensure that measures relating to the exercise of legal capacity respect the rights, will and preferences of the person, are free of conflict of interest and undue influence, are proportional and tailored to the person’s circumstances, apply for the shortest time possible and are subject to regular review by a competent, independent and impartial authority or judicial body.  The safeguards shall be proportional to the degree to which such measures affect the person’s rights and interests.

5.   Subject to the provisions of this article, States Parties shall take all appropriate and effective measures to ensure the equal right of persons with disabilities to own or inherit property, to control their own financial affairs and to have equal access to bank loans, mortgages and other forms of financial credit, and shall ensure that persons with disabilities are not arbitrarily deprived of their property.

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ISO 21542 : 2011  is available from the International Standards Organization (ISO) at … www.iso.org/

The Official Abstract on the ISO WebSite states …

ISO 21542 : 2011  specifies a range of requirements and recommendations for many of the elements of construction, assemblies, components and fittings which comprise the built environment.  These requirements relate to the constructional aspects of access to buildings, to circulation within buildings, to egress from buildings in the normal course of events and evacuation in the event of an emergency.  It also deals with aspects of accessibility management in buildings.

ISO 21542 : 2011  contains provisions with respect to features in the external environment directly concerned with access to a building or group of buildings from the edge of the relevant site boundary or between such groups of buildings within a common site.  It does not deal with those elements of the external environment, such as public open spaces, whose function is self-contained and unrelated to the use of one specific building, nor does it deal with single-family dwellings, other than those circulation spaces and fittings that are common to two or more such dwellings.

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