When thinking about automatic sprinkler protection for a warehouse, one might start by asking themselves, what will be stored in the building? That will define the fire hazard. This is a great starting point, but it’s also important to ask yourself additional questions: What type of operations will take place in the building? Will the owner have the need to store any idle pallets?   Although the latter may seem like an odd question, pallets can be a significant fire hazard—at times even greater than the commodities stored in the building. Not considering the hazard of idle pallets may result in an automatic sprinkler system that will not be effective at controlling a potential fire within the building.   Pallet fires have been shown to release large amounts of energy and challenge the effectiveness of automatic fire sprinkler systems. Stacked pallets provide airflow spaces that can optimize fire spread, while the upper pallets shield the lower ones, allowing what could be a concealed fire to rapidly develop. This type of fire is a challenge for even a well-designed sprinkler system. The 2022 edition of NFPA 13, Standard for the Installation of Sprinkler Systems, has criteria specifically for idle pallet storage in section 20.17, which is based on the type and storage arrangement utilized. It is important to note that idle pallets are treated separately from the other types of stored commodities and low-piled storage in NFPA 13.   Idle pallet storage is not limited to warehouses either. It can be a concern anywhere goods are received in bulk and broken down for sales or distribution. This may include buildings such as big-box stores, grocery stores, distribution centers, factories, and even smaller stores like pharmacies and convenience stores. Let’s review the types of pallets and configurations covered in NFPA 13 and some of the schemes provided for automatic fire sprinkler system design. Types of Pallets   Pallets can be either constructed from wood. NFPA 13 defines a wood pallet as “a pallet constructed entirely of wood with metal fasteners,” while the standard defines a plastic pallet as “a pallet having any portion of its construction consisting of a plastic material.”    The images below are examples of wood and plastic pallets. For the purpose of automatic fire sprinkler design, plastic pallets can be treated equivalent to wood pallets when it’s been demonstrated their fire hazard is equal to or less than that of wood pallets and they’ve been listed for such equivalency.     Storage Arrangements   Although NFPA 13 recognizes idle pallet storage can occur outside, in a detached building, or indoors, the standard only provides protection criteria for indoor pallet storage. In this case, pallets can be arranged in stacks on the floor and on racks without solid shelves. The height of the pallet “pile,” separation distance from other “piles,” and the height of the ceiling are all a part of the storage arrangement and will play a role in identifying the correct protection scheme. It should be noted that the storage of idle pallets on solid-shelf racks is not permitted due to the difficulty in extinguishing idle pallet storage combined with the shielding of the shelves.   Protection Schemes   Density Area Method – Ordinary Hazard Group II   When designing the sprinkler system for protection of idle wood pallets, it’s important to remember both wood and plastic pallets can be stored inside and protected by a density/area design criteria equivalent to Ordinary Hazard Group II. For wood pallets, the pile cannot be more than 6 ft (1.8 m) in height, and for plastic pallets, the pile cannot be more than 4 ft (1.2 m) in height. In both cases, the piles must be separated by a minimum of 8 ft (2.4 m) of clear space or 25 ft (7.6 m) of stored commodity. Each wood pile is limited to four stacks and each plastic pile is limited to two stacks. This scheme allows occupancies such as department stores and small factories the ability to store idle pallets in limited quantities.   Control Mode Density/Area Method   The protection schemes for wood pallets using the density/area method allow storage heights between 6 ft and 20 ft (1.8 m–6.1 m), with maximum ceiling heights up to 30 ft (9.1 m), utilizing 0.2 gpm/ft2–0.6 gpm/ft2 (8.2 mm/min–24.5 mm/min) over areas between 2000 ft2–4500 ft2 (185 m2–450 m2). When plastic pallets are not separated in a dedicated storage room, the piles can be up to 10 ft (3.0 m) in a building, with a maximum ceiling height of 30 ft (9.1 m) and a density of 0.6 gpm/ft2 over 2000 ft2 (24.5 mm/min over 185 m2), utilizing a minimum K-factor of 16.8 (240).   Control Mode Density/Area Method – Dedicated Room   Plastic pallets are permitted to be stored in a dedicated room separated from other storage by a 3-hour-rated fire wall with storage piles up to 12 ft (3.7 m) utilizing a density of 0.6 gpm/ft2 (24.5 mm/min) over the entire room and protection from the steel columns in the room. Wood pallets do not have the same protection scheme equivalent.   Control Mode Specific Application (CMSA) Sprinklers   Only wood pallets may be protected using the control mode specific application (CMSA) method. Pallet storage can be up to 20 ft (6.1 m) in height, with maximum ceiling heights between 30 ft and 40 ft (9.1 m-12.2 m). The range of available K-factor designs is 11.2–19.6 (160–280) with different criteria for minimum design pressure and number of heads in the design. Currently, storage on racks without solid shelves is not permitted with the CMSA design scheme.   Early Suppression Fast Response (ESFR) Sprinklers   Early suppression fast response (ESFR) sprinklers are designed for challenging fires, which makes them an option for idle pallet storage. NFPA 13 has protection schemes for wood pallet arrangements, both on the floor and on racks without solid shelves, at storage heights from 20 ft­–35 ft (6.1 m-10.7 m), with maximum ceiling heights between 30 ft–40 ft (9.1 m-12.2 m), utilizing K-factor designs from 14–25.2 (200–360) and minimum operating pressures between 15 psi–75 psi (1 bar–5.2 bar). The schemes for plastic pallets are not limited in storage height, but are limited in maximum ceiling height, with schemes up to 40 ft (12.2 m) in height, utilizing K-factor designs from 14–25.2 (200–360) and minimum operating pressures between 35 psi and 75 psi (1 bar–5.2 bar).   High Expansion Foam   For plastic pallets stored in a dedicated room separated from other storage by a 3-hour-rated fire wall with storage piles up to 12 ft (3.7 m), a high expansion foam system combined with a sprinkler density of 0.3 gpm/ft2 (12.2 mm/min) over the entire room and protection from the steel columns in the room can also be utilized.   Specific Test Data   Recognizing the significant fire challenge of idle plastic pallet storage, any protection scheme that is based on test data is not only permitted but encouraged to take precedent over the listed protection schemes. However, this same clause does not exist for the protection of idle wood pallets.   Summary   The storage of idle pallets is a significant fire hazard. When this hazard is not considered during the automatic fire sprinkler system design, the potential exists for a significantly undersized sprinkler system. Whether you’re designing a warehouse or simply a storage/loading dock in an office building, it is important to consider the storage of idle wood pallets in the design. The type of pallets, height of the pallet piles, and ceiling height all influence the available protection schemes. If you’re looking for more information on sprinkler system design in storage occupancies, check out the NFPA 13 Storage Protection Requirements and Assessment (2022) Online Training Series.

Automatic fire sprinkler systems have consistently demonstrated their ability to reduce the impact of unwanted fires.   But when a sprinkler system fails, many times it is due to insufficient water reaching the fire. An NFPA® research report titled “U.S. Experience with Sprinklers” found that when a system fails to contain a fire, 50 percent of the time it was because water did not reach the fire at all, and 31 percent of the time not enough water reached the fire.   These statistics underscore the importance of effectively calculating the water demand needed for the automatic fire sprinkler system; otherwise, the system may not be effective at reducing the impact of a fire.   This is the first in a series of blogs aimed at providing an overview of the basics of fire sprinkler design calculations (demand calculations) using the density/area design method found in the 2022 edition of NFPA 13, Standard for the Installation of Sprinkler Systems. Today we will focus on subsection 19.2.3, which addresses the water demand, and paragraph 28.2.4.2, which specifies the hydraulic calculation procedures specific to the density/area design method.   Density/area method   The density/area method can be generally defined as a given amount of water (sprinkler discharge rate) over a specified area. This given amount of water is known as the design density, which is intended to provide cooling and wet adjacent surfaces with the goal of controlling an unintended fire until it can be fully extinguished by emergency services. The area is the expected area of sprinkler operation, or remote area for which the given amount of water (design density) must be applied. For water demand calculations, it’s assumed all sprinklers in this area will operate. This area is often adjusted for things like quick-response sprinklers, sloped ceilings, dry-pipe, double interlock systems, and high-temperature sprinklers.   Remote area   When calculating the water demand needed for the system it is imperative that the correct location on the sprinkler system be chosen as the remote area. Although most fire sprinkler system calculations are done utilizing hydraulic calculation software, many are integrated into computer aided drafting (CAD) programs. The ability of the program to correctly calculate the water demand is directly related to the user’s ability to select the correct area.   The area selected should be the hydraulically most demanding, which is often physically the furthest point from the sprinkler riser on the system. However, in some instances, pipe sizes may make an area physically closer to the riser more hydraulically demanding. An example of this may be an instance closer to the sprinkler riser, which utilizes a more condensed spacing than the physically most remote portion of the system. When in doubt, it is best to calculate multiple areas.   Identifying the remote area   The steps in identifying the remote area involve determining the area (square footage or square meters) from the design criteria, applying the necessary adjustments to this area, calculating the shape, determining the number of sprinklers necessary in the area, and selecting those sprinklers that meet the remoteness and shape criteria. Let’s walk through a basic example for remote area selection on a system with a main line and branch lines (not gridded or looped).   The initial step is to determine the area (square footage or square meters) from Chapter 19. Since we’re utilizing the density/area method on a new system, Table 19.2.3.1.1 applies. Determining the occupancy hazard classification is very specific to the area being protected and is a bit out of scope for this blog but certainly a topic we will cover in this series. For the sake of our calculation, let’s assume we determined the occupancy to be an Ordinary Group I hazard.     You’ll notice we’re given two options for each hazard. This is because areas adjacent to combustible concealed spaces present a unique challenge—the fire may establish itself in the concealed space and a greater number of heads may activate. Let’s assume we’ve determined we are not adjacent to a combustible concealed space, so the 0.15 gpm/ft2 (6.1 mm/min/m2) over 1500 ft2 (140 m2) applies, thus our area is 1500 ft2 (140 m2). Remember, this area may be adjusted for things like quick-response sprinklers, sloped ceilings, dry-pipe, double-interlock systems, and high-temperature sprinklers. For our example, let’s assume none of these adjustments applies.   After determining the size of the remote area, we’ll need to determine its shape. Paragraph 28.2.4.2.1 indicates that “a rectangular area having a dimension parallel to the branch lines at least 1.2 times the square root of the area of sprinkler operation (A)” is utilized. As an equation that is:   L = 1.2√A Where:  L = the dimension parallel to the branch line (ft or m) A = the area of operation (ft2 or m2)   For the sprinkler operation area in this example, we get:   L = 1.2√(1500 ft2  (L = 1.2√140 m2) L = 46.5 ft (L = 14.2 m)   We’re going to assume we’re utilizing a sprinkler coverage area of 120 ft2 (11.1 m2), which is under the maximum allowable square footage for an Ordinary Group I hazard with standard-spray sprinklers of 130 ft2 (12 m2) with sprinklers spaced 12 ft (3.6 m) apart along the branch line and branch lines 10 ft (3 m) apart as shown below.     The next step is to determine the number of sprinklers in the area. To accomplish this, we’ll divide the area from Table 19.2.3.1.1 by the coverage area per sprinkler.   1500 ft2 / 120 ft2 = 12.5 sprinklers   Since it’s not possible to activate half a sprinkler head, we round the number to 13 sprinklers.   Now that we have the shape and the number of sprinklers in the design area, we apply that to our layout and select the 13 most remote sprinklers that meet our remote area shape criteria.   To meet the shape requirement of 46.5 ft (14.2 m) long, we’d need to utilize five sprinklers along the branch line. To meet the number of sprinklers, we’d need an additional eight sprinklers, five along the next branch line and three along the third. We’re permitted to utilize any of the sprinklers along the third branch line. Most commonly, the ones closest to the cross main are selected as they will result in the greatest flow. This is shown graphically below.     As you can see, even in this simple example there are nuances to selecting the design. Keep in mind, this was one of many design options for new sprinkler systems in NFPA 13. Evaluation of existing systems has separate criteria. Make sure to utilize the correct option for your situation.   Wrapping up   Even when utilizing computer software, engineers and designers need to select these sprinklers correctly to ensure they accurately provide the water demand needed in the event of an unwanted fire. Next up in this series of blogs we’ll look at the K-factor formula for determining the flow of the starting sprinkler.   For more information about NFPA 13 sprinkler system design, check out the NFPA 13 Online Training Series. The training has been updated recently to reflect the most current 2022 edition of NFPA 13. Module 2 of this training provides users with a comprehensive overview of the calculations we discussed in this blog.

It’s the time of year when we’ll start to see Christmas Trees pop up all around. The colorful ornaments and bright lights add flare to almost any room and remind us that the New Year is just around the corner. As a fire inspector, this time of year adds a whole new twist. Christmas Trees, although festive also poses a very dangerous fire hazard. The thin needles spaced just far enough apart are easily ignitable and can lead to rapid fire growth. Christmas Tree fires quickly releases a large amount of energy, placing them among the higher hazards when it comes to contents and furnishings. Natural Cut Christmas Trees can be a more severe hazard than artificial trees, especially when they go without water for even a short period of time. With such a severe fire hazard, it’s no surprise NFPA 1 Fire Code puts limits on both natural cut and artificial Christmas Trees just like it does for mattresses and upholstered furniture. Considerations for natural cut Christmas trees When placed inside a building, natural cut trees are required to be fresh cut ½” (13mm) above the end and immediately placed in water, with the water level monitored to ensure it is always above the level of the cut. So how often do you water your Christmas Tree? The answer is as much as necessary to keep the water level constantly above the cut. If the tree shows any signs of dryness, such as brittle needles that easily come off, the tree must be removed. Trees must be located away from heating vents or other heating equipment which may cause the tree to dry out. If fire retardant treatment is applied to natural cut trees it must meet both Test Method 1 and Test Method 2 of ASTM E3082, Standard Test Methods for Determining the Effectiveness of Fire-Retardant Treatments for Natural Christmas Trees. Method 1 involves the use of a detached branch where Method 2 utilizes the whole Christmas Tree to test the effectiveness of the applied fire-retardant treatment. Even with these provisions natural cut trees are prohibited from in Assembly, Board and Care, Detention and Correctional, Dormitories, Educational and Hotel occupancies. Without automatic fire sprinkler protection, trees are only permitted inside the unit of an apartment building, in an industrial occupancy and in one/two family dwellings. If the building is protected by automatic fire sprinklers additional occupancies can display natural cut trees, and less restrictions are in place if the tree roots are dug up and balled to help the tree survive. Check out the table below from NFPA 1 (2021ed) for the list of permitted locations. Considerations for artificial Christmas trees Artificial Christmas Trees also present a fire hazard like natural cut trees as they have thin needles spaced to allow rapid fire growth. Combine that hazard with the high energy release rates of synthetic materials and it warrants special provisions in both NFPA 1 and NFPA 101. Artificial trees must meet test method 1 or test method 2 from NFPA 701, which addresses the flame propagation of textiles, with the goal of limiting flame spread to limit fire growth; or a maximum heat release rate of 100kW when tested to NFPA 289 with a 20kW ignition source, where limiting the heat release rate limits the impact that adding an artificial tree will have on the fire hazard of the contents and furnishings. General considerations Regardless of the type of Christmas tree, natural cut, balled or artificial, they cannot be placed such that they obstruct corridors, exit ways, or means of egress.  Additionally, any electrical equipment used must be listed for its application. In all cases no candles or open flames are permitted on any type of Christmas tree. Inspecting and enforcing these items for all Christmas Trees goes a long way to reduce fire hazard they present. Summary During the holiday season Christmas Trees can add additional fire hazards to building contents and furnishings not present year around. Codes/Standards aide to minimize this hazard while allowing for festive holiday decorations, however their ability to reduce the fire hazard is dire directly related to the knowledge of those inspecting to and enforcing those codes/standards. For more information about how to prevent Christmas Tree fires and steps you can take to stay fire safe during the holidays check out these NFPA resources: Christmas tree safety tips Christmas tree safety video – Put a freeze on Winter Fires Deck the halls with fire safety video

Two weeks ago, I had the opportunity to attend The 1st University of Maryland/NFPA Fire & Life Safety Ecosystem Symposium, in College Park, Maryland, U.S.A, where fire and life safety experts from across the globe gathered to discuss the principals of the NFPA Fire & Life Safety Ecosystem™ and its application to address today’s fire safety issues. For those of you who are not familiar with the NFPA Fire & Life Safety Ecosystem™, it is “a framework that identifies the components that must work together to minimize risk and help prevent loss, injuries and death from fire, electrical and other hazards.” In other words, it identifies the items NFPA feels contribute to achieving the expected level of safety when it comes to fire and electrical hazards. Each component is depicted as a cog, each of which connect to form a circle. Over the two day symposium attendees reviewed case studies on the Ghost Ship Warehouse fire in Oakland, CA (2016); the Grenfell Tower Fire in London, UK (2017); and the Camp Fire, Butt County, CA (2018); and also discussed emerging issues involving residential fires; the safe use of alternative energy; and how to think about fire safety when using new building materials. Each topic was evaluated through the lens of the NFPA Fire & Life Safety Ecosystem™.  In many of the case studies multiple components of the ecosystem failed or lacked effectiveness. When discussing the emerging issues, no single component would solve the challenge presented. This seemed to lend to the idea that all the cogs must be working together to ensure the expected level of safety, so what happens if just one isn’t operating at peak performance? Does the ecosystem still provide a level of safety because the cogs remain connected? One example that came up several times was the need to mandate automatic fire sprinkler systems in all new and existing high-rise buildings. According to research done by NFPA, fire Sprinklers have been shown to be an extremely effective of increasing life safety with an 89% reduction in fire deaths in properties with automatic fire sprinklers as compared to those without. So, sprinklers would certainly make an impact on reducing deaths in fires. NFPA 1 Fire Code requires automatic fire sprinklers systems in all new high-rise building and all existing high-rise buildings within 12 years of the code becoming law. Mandating compliance with the most recent edition of this code through legislation falls under government responsibility cog. If the government responsibility cog was effective, this incorporation of NFPA 101 Life Safety Code would be one way they could create laws which prioritizes public safety needs.  However, as is sometimes the case a local government also could incorporate into law a modified NFPA 101 Life Safety Code, one which doesn’t mandate sprinklers in all high-rise buildings, specifically existing buildings. In the second case, one could argue that this cog would not be functioning at its optimal potential. How does this impact the level of safety in existing high-rise buildings? There are many examples of major fires in non-sprinklered or partially sprinklered high-rise buildings including the One Meridian Plaza fire (1991), the Cook County Administration Building fire in Chicago (2003), the Marco Polo Apartment Building Fire in Hawaii (2017) and the Twin Parks Northwest fire in New York City (2022). In all these cases a review of the fire concluded fire sprinklers could have made an impact, however all had multiple challenges; One Meridian Plaza had issues with water supply in the standpipe system; the Cook County Administration Building had locked doors preventing reentry on the floors above the fire; and both the Marco Polo and Twin Parks Northwest fires both had issues with self-closing doors. These challenges touch the Skilled Workforce, Code Compliance, and Investment in Safety cogs, resulting in the entire system failing. As I reflect on the discussion during the first NFPA Fire and Life Safety Ecosystem Summit, I can’t help but wonder if another part of the ecosystem concept is the resiliency of the anticipated level of safety in buildings. Each cog is interlaced with the next, adding elements of safety which can work together in an emergency to prevent a major tragedy. When one cog is not functioning at its optimal potential does the circular concept of the ecosystem allow the others to “turn” or function which will provide some level of safety, reducing the likelihood of a significant incident? As we wrap up fire prevention week, let’s think about all the cogs and how they’ll advance the level of safety for the public. Government Responsibility, Development and Use of Current Codes, Reference Standards, Investment in Safety, Skilled Workforce, Code Compliance, Preparedness and Emergency Response, and Informed Public all work together. Buildings which are designed, constructed, and operated with all these in mind really do have a level of safety which works to protect their occupants. Check out the NFPA Fire & Life Safety Ecosystem™page for more on the concept, an assessment tool as well as the 2020 & 2021 Year in Review reports on the state of the ecosystem.

Under NFPA 101, Life Safety Code, once a building has been approved by the Authority Having Jurisdiction (AHJ) and a new version of the code is adopted, that building becomes an existing building. Any changes to an existing building, from as small as touching up paint to as large as gutting an entire building, are covered in Chapter 43. The first step in determining the requirements for a specific change is to categorize the work being done in one of the seven work categories. The work category will drive the code requirements for the work areas so selecting the correct one is important. This blog will review the categories and walk through some examples of different projects and the category or categories they could fall under. The seven work categories are as follows: Repair - The patching, restoration, or painting of materials, elements, equipment, or fixtures for the purpose of maintaining such materials, elements, equipment, or fixtures in good or sound condition (NFPA 101 - 43.2.2.1.1 2021 edition). Renovation - The replacement in kind, strengthening, or upgrading of building elements, materials, equipment, or fixtures, that does not result in a reconfiguration of the building spaces within (NFPA 101 – 43.2.2.1.2  2021 edition). Modification - The reconfiguration of any space; the addition, relocation, or elimination of any door or window; the addition or elimination of load-bearing elements; the reconfiguration or extension of any system; or the installation of any additional equipment (NFPA 101 – 43.2.2.1.3  2021 edition). Reconstruction - The reconfiguration of a space that affects an exit or a corridor shared by more than one occupant space; or the reconfiguration of a space such that the rehabilitation work area is not permitted to be occupied because existing means of egress and fire protection systems, or their equivalent, are not in place or continuously maintained. (NFPA 101 – 43.2.2.1.4  2021 edition). Addition - An increase in the building area, aggregate floor area, building height, or number of stories of a structure (NFPA 101 – 43.2.2.1.7  2021 edition). Change of Use - A change in the purpose or level of activity within a structure that involves a change in application of the requirements of the Code (NFPA 101 – 43.2.2.1.5  2021 edition). Change of Occupancy Classification - The change in the occupancy classification of a structure or portion of a structure (NFPA 101 – 43.2.2.1.6  2021 edition). To help identify the appropriate category the flow chart below is one way to walk through the decision points for a particular work area to arrive at the rehabilitation work category. Each work area should be considered separately to ensure all requirements are captured. See a larger view of this diagram. In this method, the initial decision point is whether the work will result in a change to how the building will be used or occupied. If the work being done creates a change to the occupancy classification it is a change of occupancy, if not, it is a change of use. Although these are their own rehabilitation categories, it’s important to continue to evaluate the work associated with this change to ensure it complies with all the code requirements as a change in use or occupancy often result in additional work being performed. The second decision point will be if the work will add any areas, height or increase the number of stories, in which that case it will be classified as an addition. If not an addition, will any space or system be reconfigured? If so, it will either be a modification or reconstruction based on the level and type of work being done. If not, then the classification will be a repair where nothing is replaced or a renovation if construction elements or systems are replaced in kind. Let’s walk through a few examples of how different projects would be classified. You own and operate a warehouse and need to hire a team to manage the warehouse. The team is new to your operation and no office space exists. To address this need, you plan to convert some of the warehouse space into offices. This type of work would change how the building or space is being utilized, specifically you’d be changing from a warehouse which is a storage occupancy to offices which is a business occupancy. The work project would be classified in the change of occupancy rehabilitation work category.  Since this work also include reconfiguring space, you’ll need to continue to evaluate to see if other rehabilitation categories apply. You won’t be adding any area, height, or stories to the building. If you’re impacting an exit, the fire protection systems cannot remain operational, or the area is more than 50% of the floor the work would also be classified as a reconstruction. Otherwise, the work would also be considered a modification. Another example would be reconfiguring the entire second floor of your office building to convert the space to better serve a new tenant. The old tenant had several small offices off a hallway that provided access to the exit stairs. The new tenant would like two open office areas separated by the original corridor on the second floor. They also need a large office on the first floor, so you plan to convert two small offices into a larger one. In this instance, the use and occupancy would remain the same and the project would not add any area, height, or increase the number of floors to the building. The work would involve reconfiguring space. It would not impact a corridor or exit that is shared by more than one occupant space, and the fire protection systems and egress systems could continue to function during the construction. The work would not encompass the entire building, but since the work would involve more than 50% of the building area, it would be classified as a reconstruction. After the work has been classified in the appropriate rehabilitation work category or categories the next step would be to determine the requirements from Chapter 43. Each rehabilitation work category has a section in Chapter 43 of NFPA 101, which outlines the requirements. It is possible to have multiple categories in a single work project, that under certain conditions can be considered independently, for example the reconfiguration of a second-floor office area and the renovation of the first-floor lobby. Each of these areas would need to comply with the requirements of their specific category.  Historic buildings have their own section in Chapter 43. This is because sometimes special consideration is needed to balance historic perseveration and code compliance. To help address this, NFPA 101 allows three options for historic buildings, they can comply with: Section 43.10 for historic buildings, The applicable work category from chapter 43 or NFPA 914, Code for the Protection of Historic Structures. It may be best to investigate all three options to determine which best suits the historic structure being rehabilitated. When making changes to an existing building, whether as minor as replacing a ceiling in kind or as major as an addition NFPA 101 provides a roadmap for completing the work. The appropriate rehabilitation category will drive relevant requirements.  For more information on how to apply chapter 43 of NFPA 101 to a given building check out this blog How do I apply the provisions for rehabilitation to work at my building?, and for more on existing buildings check out this blog on Do all buildings have to comply with the latest code?

There are two main ways in which fire fighters currently receive information about fire protection features and construction types of a building they are responding to. The first is from a pre-incident plan (see NFPA 1620 for information about pre-incident planning) which is available as a result of prior building inspection and the second is through signage on the building. The most widely adopted signage which most fire fighters are familiar with is the NFPA 704 hazard diamond, which provides information about hazardous materials present and the fire, health, instability and special hazards which they pose. However, there is a lesser-known marking system that has been developed and incorporated in Appendix C of NFPA 1, which if utilized can provide fire fighters the basic information about fire protection features and building construction quickly and concisely as they’re arriving on scene of an emergency. Let’s look at why this type of marking system is important to fire fighters. Modern buildings are designed with fire protection features to protect both occupants and the building itself. Some of these features provide active protection, such as fire suppression systems, while others provide passive protection such as fire resistive construction. The required protection level is dictated by the codes incorporated by reference into law by the authority having jurisdiction at the time the building was designed and constructed, or under a retroactive requirement after the building is occupied. The specific fire protection features in a building, combined with the construction type will play a role in the tactical approaches to suppressing a fire in that building. So, having this information quickly and concisely displayed on the exterior of the building can enhance the fire department’s effectiveness. Although some states have adopted signs identifying construction type and location of truss construction, the fire fighter safety building marking system (FSBMS) in Appendix C of NFPA 1 goes further to include the hazard level of the contents, presence of fire sprinkler and standpipe systems, occupancy and life safety issues and other special designations. What does it look like?   The Maltese cross, which draws its origins from the Knights of Malta, has been widely adopted as a symbol of the fire service. The eight-pointed cross can be easily identified by its curved arcs between the points which all converge on a center circle. The FSBMS utilizes a rating system in each of the arms of the cross and the center circle to concisely display the hazard level, fire suppression systems, occupancy life safety issues and special hazards of a given building. The image above is an example of a FSBMS symbol. These signs should be located “in a position to be plainly legible and visible from the street or road fronting the property or as approved by the fire department.” To aide in visibility the signs should incorporate a white reflective background and black lettering.  Now let’s look at what each of the letters in the four sections of the cross identify. Rating System Construction Type The construction type is identified utilizing letter combinations in the top section of the Maltese cross as follows: FR — Fire-resistive construction NC — Noncombustible construction ORD — Ordinary construction HT — Heavy timber construction C — Combustible construction These construction types provide firefighters a general understanding of how well the building will resist collapse under fire conditions. Fire resistive construction would theoretically resist collapse the longest and combustible construction has the potential for the earliest collapse. Hazards of Contents The hazard of the building’s contents as it relates to fire conditions will be displayed on the left section of the Maltese cross as follows: L — Low hazard. Low hazard contents shall be classified as those of such low combustibility that no self-propagating fire therein can occur. M — Moderate hazard. Moderate hazard contents shall be classified as those that are likely to burn with moderate rapidity or to give off a considerable volume of smoke. H — High hazard. High hazard contents shall be classified as those that are likely to burn with extreme rapidity or from which explosions are likely. The hazard level will provide fire fighters with a general idea of how rapidly a fire will grow and spread through the building contents. This information can be used to anticipate the amount of water and firefighting resources needed to effectively control the fire. Automatic Fire Sprinkler and Standpipe System The presence of automatic fire sprinklers and standpipe systems will be displayed in the right section of the cross as follows: A — Automatic fire sprinkler system installed throughout P — Partial automatic fire sprinkler system or other suppression system installed S — Standpipe system installed N — None The general understanding of what active fire suppression systems are located in the building will guide firefighter’s tactics including apparatus positioning and hose line selection. Occupancy/Life Safety Issues The occupancy and life safety issues will be displayed in the lower section of the cross as follows: L — Business, industrial, mercantile, residential, and storage occupancies M — Ambulatory health care, assembly, educational, and day care occupancies H — Detention and correction facilities, health care, and board and care occupancies This information about building occupants/occupancy type will allow firefighters to gauge the difficulty in evacuating occupants from the building. The L occupancies representing those where the occupant load is lower, and occupants can most effectively evacuate unassisted. The M is of moderate concern where the occupant load is higher and/or the occupants may need additional assistance due to age or health conditions. The H is of high concern where the occupants may not be able to self-evacuate and considerable resources will be needed to evacuate the building. Special Hazards The center circle has been left empty to allow the inclusion of special hazards or provisions. This may be a location to include such things as truss type construction or even the hazardous materials information for example an NFPA 704 diamond, as long as the provisions for size of 704 are met. Summary Having the information on construction type, hazard level of contents, presence of sprinkler and standpipe systems and occupancy/life safety issues has the potential to enhance the effectiveness of firefighters arriving on scene. These responders would be equipped with the knowledge needed to best address an emergency in the building. States which have incorporated NFPA 1 into law should take the extra step to specifically name Annex C in the incorporating ordinance, thus incorporating a national standard the firefighter safety building marking system into law in their jurisdictions. Unless specifically incorporated by refence the FSBMS in Annex C would be a recommendation rather than a requirement. A national system has the potential to increase firefighter effectiveness while decreasing the number of fire fighter injuries and deaths by providing important information quickly and concisely as they arrive on scene.