Fire burns, but let’s be clear on what that means

Man is the only creature that dares to light a fire and live with it. The reason? Because he alone has learned how to put it out. – Henry Jackson Van Dyke, Jr.

Humans have learned to utilize fire’s power and enjoy its beauty and warmth, but yet we are still learning to protect ourselves from its destructive nature. In order to improve, there must be meaningful conversations and collaboration between those who study, design for, live with and fight against fire. To do so, they must all speak the same language. The English language has so many different words for concepts and ideas that are nearly identical, yet each conveys slightly different emotions, details or opinions depending on context and intent. The simple fact that each word has specific meanings allows you to (hopefully) understand what I have written here. When lives are at stake, there is no room for confusion or arguments resulting from improper use of a simple word. Knowing the exact and agreed upon definitions to certain terms used throughout the various codes and standards is also often the biggest stumbling block to understanding key concepts. The following terms are not interchangeable, and it is therefore critical that everyone understands them.

Flammable, Combustible, Non-Combustible, and Fire-Resistance

All four of these are common throughout dozens of codes and standards; the term “combustible” is used in some form almost 300 times in the IBC alone. They are also used in everyday news reports and on thousands of product labels. Once you have the real definition, you’ll be amazed at how often they are mis-used and actually lead to incorrect assumptions.

The International Building Code (IBC) and NFPA 101 actually avoid defining three of these terms in a simple sentence or paragraph because in order to be classified under one term or another, the material must be tested in a recognized manner. If the definition of what combustible meant was summarized by a highly interpretable paragraph, nobody would ever fully agree on whether something was or was not combustible. Basing a definition on whether something has passed a consistent and widely accepted set of criteria and even testing helps to reduce interpretation errors.

The first two are often used interchangeably, but should not be:

Flammable versus Combustible

Here are some official definitions. Note that I’m including the definition of noncombustible because combustible is defined as anything that cannot be called noncombustible. Yes, I know the thought, “Well, Duh…” entered your head, but it’s actually an important point.

Flammable: capable of being easily ignited and of burning quickly – Merriam-Webster.com (1)

Flammable Material: A material capable of being readily ignited from common sources of heat or at a temperature of 600°F or less. – 2015 IBC

Combustible Material: A material that, in the form in which it is used and under the conditions anticipated, will ignite and burn; a material that does not meet the definition of noncombustible or limited- combustible. – 2012 NFPA 101

Noncombustible: A material that complies with any of the following shall be considered a noncombustible material:

(1)*  A material that, in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat

(2)  A material that is reported as passing ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 Degrees – 2012 NFPA 101

There are three key differences in these terms:

  • Flammable material ignites from common heat sources or at a temperature less than (or equal to) 600°F. Combustible material is ANYTHING that ignites, burns, supports combustion, etc… at any temperature or from any fire.
  • The term flammable is most commonly used to refer to fabrics, furnishings, decorations, clothing, and other such non-building related components. Combustible is more often used to describe a building material or finish that will burn.
  • Combustible materials are defined as those that would FAIL the ASTM E 136 test.

Using these definitions: All flammable materials are also combustible. Combustible materials are not always flammable. Whoa… what did he just say? Let me give an example:

A product that has been a big part of recent headlines is the metal composite material (MCM, or ACM) Reynobond PE®. It is composed of aluminum sheets (a non-combustible material) with a polyethylene foam core. Polyethylene foam ignites at a temperature of 340℃ (644℉) (2). Because the foam ignites at all it is considered combustible. The panels however would not be considered flammable as the aluminum skin does not burn (keeping flame away from the inner core under “common sources of heat”), and below 600℉; the foam core does not ignite. In this particular case, the material is NOT flammable by definition. It IS combustible. I would encourage you to read my first blog post for more discussion on the Grenfell Tower fire.

Ok, so flammable and combustible are different, but it’s just semantics right?

Noncombustible and Fire-Resistance

Let’s look at the other two terms: Noncombustible and Fire-Resistance / resistive. These unfortunately are used in similar ways, but do NOT have the same meaning.

Noncombustible: A material that complies with any of the following shall be considered a noncombustible material:

(1)*  A material that, in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat

(2)  A material that is reported as passing ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 Degrees C

– 2012 NFPA 101

Fire-Resistance Rating: The period of time a building element, component or assembly maintains the ability to confine a fire, continues to perform a given structural function, or both, as determined by the tests, or the methods based on tests, prescribed in Section 703. (Those tests are ASTM E 119 or ANSI/UL 263) – 2015 IBC

A material that will not ignite or burn in any way, such as steel, is considered non-combustible. Steel on its own however, does not maintain its structural strength when subjected to high heat, and therefore has a very low (if any) fire-resistance. It may sound hard to believe, but a heavy timber column (say 12 inches x 12 inches in dimension) will remain structurally sound much longer in a fire than the same size steel column.  Another common example is cementitious siding (known by the brand name HARDIEPANEL®). This product is non-combustible (3), but does little to confine a fire as it can quickly fall apart when subjected to an actual fire reaching more than 1,500℉, and therefore has little to no fire-resistance.

If you want to protect and separate the occupants of a building from a fire, you need materials and systems that are fire-resistive. They actually remain in place and hold together long enough to keep the fire away or hold the building up. There are fire-resistive systems constructed of non-combustible materials and just as many that are made with combustible materials.

Fire-resistance is not an issue of will it burn or not (combustible versus noncombustible); it is determined by how long a material or system will resist the fire and protect a building’s occupants.

It’s impossible to design, construct, or correctly maintain a building that protects its occupants if these terms are used incorrectly; besides, you’ll sound smarter using the right one.

More Information:

There are plenty of other terms related to building codes that are mis-used or mixed up that I know we’ll discuss later.

For additional information on fire-resistive properties of Aluminum Composite Materials (ACM) and the fire-resistant testing procedure ASTM E 119, please take a look at the following videos from Alucobond® and National Gypsum®.

https://youtu.be/Ku79wNywrDU

https://youtu.be/lgqDx646s-U

Footnotes:

  1. https://www.merriam-webster.com/dictionary/flammable
  2. Q & A on Fire and Fire Prevention of Rigid Polyurethane Foam, May 2009, Translation into English by JUII Fire Safety Committee from revised Japanese text, December 2011, Japan Urethane Industry Institute (JUII). http://www.urethane-jp.org/topics/doc/Q&A_on_Fire_and_Fire_Prevention_of_Rigid_Polyurethane_Foam_REV1.pdf
  3. ICC-ES Report, ESR-1844, HARDIEPANEL® (PREVAILTM, CEMPANEL®) SIDING, HARDIFLEX® SIDING AND HARDITEX® BASEBOARD https://www.jameshardie.com/JamesHardieMainSite/media/Site-Documents/TechnicalDocuments/Reports/ESR-1844.pdf

Codes 101

Understanding the intricacies of building and life safety codes is simply a matter of learning why they exist, how they are used, and where to get started.

The codes and standards used to regulate the construction, maintenance and general use of nearly every structure in the United States can seem confusing, frustrating and even occasionally contrary to common sense. Like so many other aspects of modern life, specific skills and knowledge are needed when dealing with highly specialized subjects. It isn’t reasonable to expect everyone to amass the in-depth knowledge of biology, anatomy and chemistry needed to be a doctor; nor is it possible for everyone to have the skills and talent needed to compose, conduct or play the violin in a classical symphony. While music may require more talent than architecture and construction (in my opinion), they both require practice and a lot of learning. Understanding the intricacies of building and life safety codes is simply a matter of learning why they exist, how they are used, and where to get started. Although seemingly complex, once you have the basic concepts down, the code is something akin to the “Choose Your Own Adventure” book series produced by Bantam Books in the 1980’s and 1990’s. Given one set of decisions, the codes send you in a specific direction for requirements and additional choices to make. Maybe there was a reason I enjoyed those stories as a kid, because as a self-described Code Geek, I find it rewarding to track down code requirements and learn new things everyday (sometimes with negative results, but often with positive ones). Codes are critical to protecting the health, safety and welfare of the public through consistency and minimum levels of quality and protection. The codes were not created in a vacuum by politicians trying to increase tax revenue or regulate just for the sake of control. Every code and standard in use today began with individuals and groups getting together when agreed upon standards were needed; often in response to tragedies and failures that could have been avoided. The codes exist because of one reason; people caring for the safety of others.

What is a code, and who can enforce one?

The building and life safety codes today are published documents, rule books if you will, that provide guidance and limitations on a wide variety of topics and disciplines. The codes are generally written by both non-profit and private groups, and then published for use. The codes themselves are only words on paper until they are actually adopted by a jurisdiction that has the legal right to do so (such authority is typically given through federal, state, county or local government laws).

This is the single most important concept to understand: A code must be adopted by a governing body such as a federal, state, county, city or other such jurisdictional entity in order to be considered actual law.

Once adopted, that Authority Having Jurisdiction (AHJ), is now responsible for enforcing the provisions and requirements of the code. AHJ’s may also include taxing entities like water and utility districts, emergency service districts (fire and police services) and health departments. Once adopted, the code is the law of that jurisdiction and they are now responsible for not just enforcing it, but also the interpretation and even amending of it to suit their specific needs.

Most jurisdictions will also rename it to become their code. The City of Dallas, Texas, has adopted the 2015 edition of the International Building Code, and in doing so renamed it as the “Dallas Building Code”. (1) Technically under Texas state law, and many other states as well, a jurisdiction could write their own code from scratch so long as it meets the minimum safety standards as a published code. I’m not aware of any municipality willing to spend the time and money necessary to write their own code in lieu of starting with a nationally published one. In the end, although originally published by various organizations, those groups are not responsible for its enforcement, and do not have any authority to officially interpret the code; only the AHJ has that authority. Most AHJ’s will look to the original publisher for guidance, but it is the AHJ that makes any decisions needed. The key idea to remember is once adopted, it is their code.

An abbreviated history of US Life Safety Codes:

Prior to the 1890’s, no formal codes, standards or even guidelines existed to maintain consistency among the early pioneers and inventors of two burgeoning industries; Fire Sprinkler Systems and Electrical Systems. Following the invention and patenting of the first sprinkler head by Henry S. Parmelee of New Haven, Connecticut in 1874, and significant concerns surrounding electrical installations at the Chicago World’s fair and across the United States in 1893, interested groups began to meet and discuss the need for standards and rules for such systems. As expected, any early attempt at consolidating personal opinions and solutions would be unlikely, and at the end of 1895, there were five distinct electrical codes in the United States and no defined standards for sprinkler systems.

In 1896, and again in 1897, several national organizations met in New York in an attempt to consolidate the various standards, and in 1897, the “Joint Conference of Electrical and Allied Interests” established the “National Electrical Code of 1897” which was adopted and issued by the National Board of Fire Underwriters. This would eventually become NFPA 70, the National Electrical Code (NEC)

Also in 1896, a separate meeting was held in New York City by parties trying to consolidate standards for fire sprinklers; their release of sprinkler installation rules entitled, “Report of Committee on Automatic Sprinkler Protection” eventually became “NFPA 13”.

In November of 1896, a new organization known as the “National Fire Protection Association” (NFPA) was formed from many of the same members previously involved. The long history of NFPA and its members is a tribute to the thousands of individuals who have volunteered their time to establish rules and standards. (2)

The NFPA would then continue to play a large part in the development of new safety standards. As is the case with many codes, tragedies such as the Triangle Shirtwaist Fire on March 25, 1911 in which 147 people perished led to the development of the “Building Exits Code”, which would later become NFPA 101, The Life Safety Code. Although it existed at the time, the Building Exits Code was widely ignored, and further tragedies occurred such as the 1942 Cocoanut Grove Fire in Boston, Massachusetts in which 492 people died, and the 1958 fire at the Our Lady of Angels School in Chicago in which 90 students and 3 nuns died. Established criteria in the Building Exits Code prohibited the unsafe conditions in both buildings which led to the high loss of life. The Code was reorganized and renamed the Life Safety Code in 1966. Even with the codes existence, and attempts by the NFPA and other life safety professionals to affect public policy and concern, subsequent fires continued such as the 1977 Beverly Hills Supper Club in which 164 people died and the 2003 Station Nightclub fire in Rhode Island in which 100 concert attendees perished. Every tragedy has led to changes in the code, but in each case, significant loss of life could have been avoided if the rules of the code had been followed. (2)

What about the Building Codes?

As in any free society, many people with the same positive intentions cannot always agree, or for various geographical or societal reasons cannot centralize their ideas. Such is the history of building codes in the United States. Three major organizations published building codes beginning in 1927 (earlier editions did exist for one of the three in 1905).

The three major codes were:

The Basic / National Building Code (BBC), first published in 1950 by the Building Officials and Code Administrators (BOCA); used primarily in the Midwest and Northeast United States

The Uniform Building Code (UBC), first published in 1927 by the International Conference of Building Officials; used primarily in the Western states, and

The Standard Building Code (SBC), first published in 1945 by the Southern Building Code Congress International (SBCCI).

In 1994, the three model code organizations created the International Code Council (ICC) to create a single set of model codes that would provide uniformity across not only the United States, but to help facilitate international use and promote innovation worldwide regarding new testing, research and products.

The ICC published its first set of model codes in 2000, consisting of the International Building Code (IBC), Fire Code (IFC), Mechanical Code (IMC), Plumbing Code (IPC), and others. These model codes have since replaced the BBC, UBC and SBC nationally, and are even used outside of the US. (3)

So what is the difference between the Life Safety Codes and Building Codes?

Building codes strictly control the allowable size, number of stories, height and structural systems used in any new building. They deal with gravity, wind, earthquake, snow and rain loads. The building codes deal with materials and systems with regards to structural integrity, water intrusion, durability, energy efficiency, accessibility and myriad of other topics. They also include many of the same requirements as the Life Safety Code with regards to fire protection, egress systems, fire sprinkler and alarm systems, etc.

Life Safety Codes such as NFPA 101 do not dictate building size, structural requirements, overall building area, or initial permitting. The Life Safety Code is concerned with one thing; the safety of life. I know it sounds repetitive, but the Life Safety Code is concerned with protecting the occupants during a fire while they stay put, or protecting them long enough to evacuate from a building or structure. While the building codes also prioritize the safety of the occupants, the Life Safety Code focuses solely on that idea.

So why can’t we just use the building codes?

This is a subject of great contention amongst those who design and construct any building that may have more than one AHJ. I believe it comes down to jurisdictions not stepping on each other’s toes. I will use healthcare in the United States as the example, because it’s easier to explain and is the focus of my own career. Every nursing home in the United States that wishes to receive federal funds under the Social Securities Act (whose programs include Medicaid and Medicare), must meet the federal requirements administered by the Centers for Medicaid and Medicare Services (CMS). They must also be licensed by the state in which they are built. CMS is a federal agency, and therefore its rules must cover every situation that may arise in every state, county and city. While some people would not want a federal agency telling them how to build or maintain their facility, you can guarantee that if a fire occurred in a nursing home which received federal funding, someone is going to look at the government for answers as to why it wasn’t safer.

So, why not let the local AHJ handle that safety issue on their own? The simple answer is that it’s not always possible. There are millions of Americans who live in areas of the country that have no adopted building code or even a local government capable of adopting or enforcing one. Texas is a prime example, in that areas outside of a city’s jurisdiction are not required to have a building permit and county governments are only allowed (not required) to adopt fire codes and not building codes. Trust me, I was as shocked to learn that one as many of my readers will be.

Remember, that a code is just words on paper unless a governmental agency adopts and enforces it. If no local enforcement agency exists, then CMS in this case MUST have a set of standards to meet. You can imagine the disaster if CMS only enforced safety standards for some areas of the country and not others. CMS is also kept from enforcing a building code as, there again; imagine the issues with a federal agency issuing and granting permits, and inspecting all construction in the United States on every single project it funds (even indirectly). I don’t care what your political affiliation may be; that’s just not a good idea.

Keeping the building codes and Life Safety Code separate allows for various AHJ’s to protect their citizens, without overstepping their bounds (too much).

So where do you get started?

Sounds like a good idea for my next post; a basic primer on the IBC and Life Safety Code. If there are other general topics regarding codes you have questions on, please leave a comment.

References / Footnotes:

(1) City of Dallas, Texas, Building Inspection, Construction Codes

http://dallascityhall.com/departments/sustainabledevelopment/buildinginspection/Pages/construction_codes.aspx

(2) History of NFPA, NFPA.org

http://www.nfpa.org/about-nfpa/nfpa-overview/history-of-nfpa

(3) Building Codes, IMUA, 1998

http://www.imua.org/Files/reports/Building%20Codes.html

Copyrights:

All NFPA Standards, Cover Images and references are copyrighted by the National Fire Protection Association®, One Battery Park, Quincy, Massachusetts 02169-7471. All references and images reproduced above are for educational and reference purposes only.

The International Building Code® and all other similar codes referenced above are copyrighted works by the International Code Council, Inc., 4051 West Flossmoor Road, Country Club Hills, IL 60478. All references and images reproduced above are for educational and reference purposes only

Codes must be followed to be effective; Immediate lessons from the Grenfell Tower tragedy.

grenfell-tower-fire-1704-hero
Photo from https://static.dezeen.com/

A huge amount of information has flooded the internet and media outlets regarding the possible causes and now future ramifications of this tragedy. As the exterior cladding of the building is being initially blamed for the fire’s rapid propagation, the presence of such a material on dozens of other government owned housing blocks has led to large-scale evacuations of residents, putting thousands of people out of their homes.

This fire will no doubt lead to civic and criminal investigations in the UK, but what can those of us in the United States learn from such a disaster? The worst possible outcome for those of us watching from across the Atlantic would be complacency, “Oh, that wouldn’t happen here.” Really? Are you sure?

What went wrong?

Initial investigations by local authorities and news organizations has focused on a “flammable” exterior cladding installed during a recent renovation project to the Grenfell tower and others like it. The product installed (allegedly confirmed by the manufacturer) was a Metal Composite Material (MCM) as defined by the International Building Code (IBC), a model code that has been adopted in some form across all fifty states in the US. The MCM installed on Grenfell Tower is a product called Reynobond PE, manufactured by Alcoa Architectural Products, located in Eastman, Georgia. Reynobond PE consists of layers of Aluminum sheets over a polyethylene core (foamed plastic). The panel as a whole meets IBC flame spread requirements (Class A per ASTM E84), however the polyethylene core on its own does not. The product is manufactured in accordance with US standards and is permitted for installation on buildings as high as 75 feet tall per the IBC, with VERY specific exceptions. The primary exception is that such a product cannot be installed on a building higher than 40 feet above the ground unless that building is equipped with an automatic sprinkler system, and then never installed above 75 feet above the ground. Alcoa also produces a product called Reynobond FR, which has a mineral board core that meets the ASTM E84 flame spread requirements on its own.

Another likely cause of the fast growing fire was the way in which exterior columns were clad in MCM panels. Quickly looking at the plans of the Grenfell Tower, listening to reports and interviews of tenants, and reviewing images of the devastation itself, one can quickly see several problems that possibly led to the fire’s growth and more importantly made it extremely difficult to for residents to escape the building before conditions became untenable.

Grenfell.jpg
Photo from: https://cdn.saleminteractivemedia.com

Grenfell Plan

  • There appears to be a relatively large gap between the cladding material and the structural columns of the building itself along the exterior. This kind of cladding style is called a “curtain-wall”, as it is attached to the face of the building, and does not terminate at each floor, but creates its own cavity on the building’s perimeter. looking at the pictures following the fire, the space between the structural column and the cladding is quite large. Per the IBC, this kind of curtain wall assembly must be
    Grenfell Colored Elevation.jpg
    Images from : http://i.dailymail.co.uk

    firestopped at each floor level using a Perimeter-Fire-Containment System such as those tested and listed in the UL Certifications Directory (systems such as CW-D-1001).

  • Grenfell Tower had only a single exit stairway. For a 24 story residential high-rise, which would have an occupant load of no less than 22 people per floor (based on the floor plan of Grenfell Tower and the 2003 IBC), a minimum of 2 stairways would be required without exception.
  • The building did not appear to have an automatic sprinkler system or manual fire alarm system interconnected with automatic detection devices.

All of these factors likely contributed to the fire’s rapid growth and the inability for residents to evacuate fast enough.

Codes have to be followed to be effective:

You may say then, “Well, those issues can’t happen here because our codes don’t allow it”. This is where the truth really matters. It can happen here. Having the rules to follow doesn’t mean that everyone follows them. Having laws that limit the speed on every highway in America does not keep thousands of people from breaking them every day. I could not begin to list all of the code violations I have witnessed over my career that were either simple mistakes, intentional omissions, or a lack of understanding about what the code really requires. The third reason is actually the scariest one. Honest mistakes happen, and I’m sure intentional code violations exist as well, but in my experience, the most common reason codes are not followed, is because designers, owners and contractors don’t understand them. Ignorance is not bliss, its dangerous.

Although I have not seen a building constructed with too few stairways, I have seen plenty of stairs that were not protected from the rest of the building, had blocked exit doors at the bottom, were too narrow, had locked doors going into them, or some other issue that essentially eliminated them as a possible exit. Having the stair doesn’t mean anything if you can’t use it.

Having a fire alarm and fire sprinkler system is absolutely worthless if the systems are not installed correctly and then routinely inspected and maintained to ensure they work. Having a sprinkler system means nothing when it fails to work because someone unintentionally blocked a sprinkler head or closed a valve.

The exterior columns at Grenfell Tower, if it does turn out to be the issue it appears to be, is due to a lack of understanding on how a fire acts, and why the building codes are written to limit the spread of a fire. This exact issue could happen in the US if a contractor substitutes a less-expensive product (like the Reynobond PE instead of using the FR version), having no other intention than saving the owner money, but the design team is either not part of that decision, or fails to understand its ramifications. Whether the PE or FR product was used, a building official in the US could easily miss the requirements to firestop the perimeter of each floor at such a system. Such omissions could result in a similar fire without anyone even knowing the issue exists.

What can you do?

Educate yourself. Surround yourself with educated people if you can’t understand the requirements yourself. The costs are too great to downplay or ignore anything having to do with fire safety and building codes in any type of construction.

Ignorance is not funny and not acceptable. Education and knowledge are our greatest asset in preventing tragedies such as the Grenfell Tower fire from happening again.

Sources:

https://www.nytimes.com

http://www.dailymail.co.uk/

https://www.arconic.com

Notice: The commentary above regarding possible causes and circumstances surrounding the fire at Grenfell Tower are personal speculations and assumptions. Educate yourself on the facts. Listen to the evidence presented to you and research the actual laws and codes that were applicable. That’s my entire point.