Automatic Sprinkler and Fire Alarm Systems

Don’t believe everything you see in the movies; here is a layman’s guide to fire sprinkler and fire alarm basics.

The myths and misconceptions surrounding fire alarm and fire sprinkler systems in movies and television is pretty staggering. As a design professional, I roll my eyes every time I see a character activate a manual pull station resulting in every fire sprinkler going off. Of course you might say, “It’s a movie; lighten up!”. On one hand; you’re right. It is only fiction. On the other hand, the consistency in which fire alarm and fire sprinkler systems are incorrectly shown actually leads to complacency and misunderstanding. In the not so distant past, I actually explained how a sprinkler works to a coworker, and they were floored that what they’d see in the movies was not correct. Entertainment is fine; I’m a big movie person myself. When no one actually explains how the systems really work to the average person, and the movies are all they know, it could actually lead to a delay in evacuation or other events that could put a person’s life in danger. I’m not suggesting changing the movies; let’s just talk about how the systems actually work. I’ll try and do so in the least technical way possible. To start, here’s some examples (from two movies I actually like) of movie imagination with regards to fire alarm and sprinkler systems. After the show, I’ll follow with some basic concepts and history for you:

Concepts and History:

Automatic sprinkler and fire alarm systems are two crucial components of a building’s life safety systems. They are what’s known as active protective systems. Passive protective systems such as fire-resistive construction, protected stairways, smoke barriers and fire walls are intended to be the main line of defense in the protection of occupants against a fire. Fire alarms are there to actively notify occupants of a fire so they can evacuate, and automatic sprinkler systems are intended to help suppress the fire long enough for the fire department to arrive and extinguish the blaze. While typical light-hazard sprinklers may often extinguish a small fire, their purpose is to keep it from growing; not put it out. More specialized systems are actually designed to fully put out a fire, but those are normally reserved for high hazard occupancies such as large storage buildings, hazardous material handling and very large mercantile buildings such as big box stores like Home Depot, Costco or Walmart.

Automatic sprinkler systems have been in existence since the late 1800’s, beginning with Henry S. Parmelee’s invention of the first sprinkler head in 1874. While improvements have been made in sprinkler design and the various system components, such as valves and piping; the basic concept of automatic sprinkler systems has not changed that much in almost 150 years.

The earliest fire alarm systems involved nothing more than a person keeping watch in the streets who would then alert the fire brigade. With the invention of the telegraph in the early 1840’s by Samuel F. B. Morse, cities such as New York began to construct municipal alarm systems of communication between fire stations and government buildings. This reduced the time needed to alert the fire brigade and improved response time through better directions. By 1880, manual fire alarm signal boxes had been patented by John Gamewell and his brother-in-law James M. Gardiner. At that time, the Gamewell Company held a 95% share of the United States market for fire alarm systems. William B. Watkins designed the first electric fire sensor / heat detector in the early 1870’s and in 1873 formed the first private fire alarm company, Boston AFA; known today as AFA Protective Systems.

In the early 1900’s, leading fire alarm and fire sprinkler companies such as ADT (American District Telegraph), Holmes Protective, AFA, Grinnell and Automatic Fire Protection (AFP), established contracts with each other to supply detection equipment, sprinkler systems, sprinkler system supervisory equipment and central station monitoring services.

In 1939, Swiss physicist Ernst Meili invented an ionization chamber which could detect combustible gases in mines and a cold cathode tube that could amplify the small signal generated to a level sufficient to activate an alarm. By 1951, the first ionization smoke detectors were sold in the US. The photoelectric (optical) smoke detector was then invented by Donald Steel and Robert Emmark of Electro Signal Lab in 1972. The technologies and devices used in fire alarm systems have continued to advance, but the basic concepts remain the same.

Fire Alarm Systems: The Basics

Fire alarm systems are required to be installed in accordance with NFPA 72, the National Fire Alarm Code. (Disclaimer: The following explanations are in layman’s terms and intentionally omit and generalize some technical details, devices and system components for clarity).

Fire Alarm Systems are made up of three basic categories of devices:

  1. Initiating
  2. Notification
  3. Control / Transmission

Initiating Devices:

These components do exactly what you think they would; they initiate an alarm. They include both automatic and manual means of activating the alarm system. The most common manual device is the “Manual Pull Station”. This would be the red device on the wall labeled “Pull in case of fire” or something similar. When the handle of this pull station is moved it literally flips a switch inside the box that tells the system to go into “Alarm”.

The three most common automatic initiating devices are smoke detectors, heat detectors and sprinkler system flow switches. The first two are self-explanatory. When a smoke detector sees (or senses) smoke, it tells the system to go into alarm mode. If the heat detector senses a rise in temperature above a set point, it also tells the system to go into alarm mode. The third item is a component that few people outside the construction, design, or fire protection industries even know exists; the flow switch. A flow switch is a device installed into the piping of the fire sprinkler system just after the water pipes enter the building. The typical flow switch has a round “paddle” or disc that is directly inside the pipe and connects to a lever and electronic sensor. When the sprinkler system activates, water begins to flow through the pipes. When the water moves, this ‘paddle’ also moves; raises the lever and sets off the sensor. This tells the fire alarm system that a sprinkler has activated; also resulting in an alarm.

In a typical light-hazard occupancy sprinkler system ,which are the most common, this is the ONLY interaction between the sprinkler system and the fire alarm system. When water flows; the alarm goes off. It does NOT work the other way. Setting off the fire alarm DOES NOT activate any or all of the fire sprinklers. Unless the system being discussed is for very unusual situations like hazardous materials, locations with jet fuel, etc.; the fire alarm system and sprinklers are not set off electronically in any way. We’ll discuss how a sprinkler system works next.

Notification Devices:

These include two main appliances, commonly referred to as a horn and a strobe. The horn is what it sounds like; it’s that really loud and annoying noise maker that lets you know there is a fire and to GET OUT. The strobe is the light emitting device that flashes when the alarm activates. Strobes are there in case occupants are hard of hearing or ambient noise levels are high enough to prevent people from hearing the horn. The horn can also be a recorded announcement in some occupancies. These two devices are there to let you know a fire or another emergency is present and you need to act accordingly. Very commonly both devices are combined into a single appliance called… you guessed it: a horn-strobe. We look for humor in this subject matter wherever we can find it.

Control / Transmission Devices:

This is my own general category for the main Fire Alarm Control Panel (FACP), Fire Alarm Annunciator Panels (FAAP), and automatic dialing devices. All of the initiating and notification devices are connected to the FACP. When an initiating device is tripped, the FACP activates all of the notification devices to let people know there is a problem. If any systems are required to shut off when an alarm is activated (mechanical units, electronic door locks, magnetic door hold-opens, etc.), the FACP will send signals to that equipment accordingly. Most modern FACP’s also include the auto-dialer device. This is literally a phone / modem that calls a monitoring service and says, “We have an alarm. The following initiating devices were set off….” The monitoring company will then notify the fire department. As all of this is done electronically, there is very little delay between when a device is set off and when the fire department is notified. The FAAP (as shown below) is basically a twin to the control panel from the FACP that can be located at strategic locations without having to install the larger control box in public areas.

Fire Alarm Systems

Those are the fire alarm basics. Although the wiring, programming and code requirements surrounding what devices are required, where they go, and how they must work are more complex, the basic concepts of initiation, notification and transmission are pretty simple.

Fire Sprinkler Systems: The Basics

Automatic Fire Sprinkler Systems must be installed in accordance with NFPA 13, NFPA 13R or NFPA 13D. 13R is generally for multifamily and hospitality occupancies like apartments, condos, hotels, motels and dormitories. 13D systems are for single family homes or duplexes. The NFPA 13 compliant system is what you would normally see in any commercial, institutional, educational or other public type building. The 13R and 13D systems use the same types of sprinkler heads; they just have less restrictive requirements in where sprinklers are required, and what kinds of equipment and other devices are installed.

The central component to a sprinkler system is… no big surprise: the sprinkler.

Fire Sprinkler
Typical ‘pendant’ type sprinkler head

The most typical sprinkler installed has 4 main parts:

  1. The cap: a disc that covers the hole the water shoots out of;
  2. The thermal linkage: the colored glass tube or metal piece that bursts or melts at a certain temperature. The linkage holds the cap in place;
  3. The deflector: The metal disc or plate that the spreads the water out, and
  4. The frame: the “arms” of the sprinkler head that hold the deflector, cap and linkage all together.

So how does a sprinkler go off? Its rather simple. The most common thermal linkage you will see today is a glass bulb with a colored liquid inside. That liquid is a mixture of water and alcohol or glycol with a colored tint. The color indicates the temperature at which the bulb is designed to burst. Per NFPA 13, bulbs that are red in color activate at 155°F. Other colors such as green, yellow, or blue indicate higher temperature ratings.

When a fire gets large enough to raise the air temperature in a room (at the head itself) to a level equal to or above the head’s rating; the glass bulb bursts. With nothing to hold it in place; the water pushes the cap out of the way; water rushes through the opening (called the orifice), and then spreads out in a pre-defined pattern as it hits the deflector. That’s how a sprinkler gets activated. There are no electronics, no manual levers or special keyed switches. The bulb gets hot; it breaks; water comes out. The only heads that will go off in a fire are those that have been heated to that specific temperature.

If EVERY head went off in a building at once (as the movies like to show), the amount of water necessary would be as much as fifty to a hundred times greater than any normal building has available. Sprinkler systems are designed to have no more than 4-6 heads go off in a fire (that is a very general statement I know; the exact number of heads is a code requirement and up to the system designer and is dependent on a number of different factors). What you see in the movies is just not physically possible in any typical building. There are specialized systems in which a large number of heads are activated at the same time, but those are not used in any building the general public normally occupies.

There is of course more to a sprinkler system than just the sprinkler heads. Every head is connected to pipes made of steel or CPVC (specially designed plastic pipe). The pipes with heads on them are commonly referred to as branch lines, while the larger pipes that feed the branch lines are called mains. The single big pipe that supplies the mains is called the riser. The riser is located inside the building right after the main water pipe enters the building. The riser typically includes shut-off valves, pressure gauges, test valves, the flow switch (connected to the fire alarm system as mentioned above), backflow preventers, and other devices needed to maintain and test the system. A typical NFPA 13 system will also have a Fire Department Connection (FDC) at the riser (or a remote one that connects to the riser) which allows the fire department to connect a pump truck and supply the system with a higher flow and pressure than the normal water system may be capable of.

Main riser with valves, main drain and pressure gauges

The kind of system described above is known as a “wet” system because the pipes are always full of pressurized water. Water freezes however, so another common system known as a “dry pipe” system is often used in attics or other areas where no heat is available during winter months. In this system, the heads are actually the same, but the branch lines and mains are filled with compressed air. The water from the utility provider is kept at bay in the riser, by a special valve and the compressed air in the system itself. When a fire causes the sprinkler head bulb to burst, the process is the same, except the system has to first purge itself of the compressed air, and then the water comes rushing in behind. Same concept; it just slightly delays the water actually hitting the fire.

The basic concepts and components of a fire alarm and fire sprinkler system are not difficult to understand. In fact, they are simple enough that everyone should know how and when each system would go off, and how it generally works. Knowing these basics makes using them that much easier and safer.

Would you like know more?

This is a VERY broad overview of fire alarm and fire sprinkler systems. What components or requirements of these systems would you like to know more about?

Sources, Disclaimers and Copyrights:

  • Fire Alarm System Research – Where it’s been and where it’s going, Wayne D. Moore, P.E.

  • Sprinkler image: Courtesy of
  • Fire Alarm device images are the property of Potter Roemer Fire Pro., Copyright 1937-2016
  • Fire alarm control and annunciator panels images are the property of Silent Knight, by Honeywell, Copyright 2017.
  • Excerpt from Lethal Weapon 4, Copyright Warner Bros. Pictures, 1998
  • Excerpt from Casino Royale, Copyright Columbia Pictures, 2006
  • Fire Truck Image is the property of the City of Leander Texas Fire Department (actually one block from my office; thank you gentlemen).
  • Fire riser image is by DFD Architects, Inc., Copyright 2017.

All images and videos included or linked to are for reference and educational purposes only. All copyrights are the property of their respective owners.

Disclaimer: I am not a licensed fire alarm or fire sprinkler RME (Responsible Managing Employee) or installer. All fire alarm and fire sprinkler systems shall be designed and installed by appropriately licensed professionals in accordance with applicable state and local laws. The above commentary is from my personal experience and code knowledge, but should not be substituted for advice and direction from trained and licensed professionals in fire alarm and fire sprinkler design and installation.


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

(2) History of NFPA,

(3) Building Codes, IMUA, 1998


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.

Photo from

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.

Photo from:

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 :

    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.


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.