BY JAMES MASON
On arrival at a residential structure fire, many problems must be solved within a very short time. Sizing up conditions, identifying hazards, and communicating with responding companies often must be done in the first few critical minutes. Although some size-up factors (i.e., fire conditions) can be observed only during an actual fire, many other factors can be analyzed during prefire planning. This is an excellent way to get all members to “read” a fire building in the same way as well as practice sizing up factors pertaining to their specific engine or truck function.
Although formalized prefire plans are usually written for large commercial, institutional, and residential buildings, one-, two-, and three-family residential occupancies can also be preplanned by noting similarities in construction and layout. Emergency medical service (EMS) runs can be an excellent opportunity for firefighters to familiarize themselves with small residential buildings they otherwise would never enter except for a fire or other emergency. Preplanning can also be done during company drills. Members could discuss similarities in the residences in their response district and formulate tactics for each general design they may encounter.
Basic preplanning should be concerned with three fireground size-up factors: how the building is constructed and how it will perform under fire conditions; the occupancy, which will indicate how many victims may be inside and their locations; and the floor plan—how it will influence the hose stretch and search and rescue operations.
Determining the age of your district will help you identify the different types of construction, occupancies, and floor plans you will encounter. If your response area is close to downtown, it most likely would contain a great variety of construction styles. These areas were originally built using ordinary and balloon-frame construction. After some of these buildings burned down over the decades, some vacant lots were filled in with platform frame construction. Some areas bordering the downtowns of large cities were “revitalized” during the 1980s and 1990s and now house affluent young professionals who occupy buildings constructed with lightweight components or older buildings that have been renovated, most of which include lightweight trusses or I-joists. This “rehabbed” blend of old and new construction may look “trendy,” but it can be dangerous for firefighters who fail to recognize a lightweight truss in a building restored to its original appearance.
 (1) A view of ordinary construction from the street. (Photos by author.) |
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 (2) The same building. You can see the header courses of brick by looking down the side. Always look at as many sides of the building as possible to determine construction, occupancy, and floor. |
In addition, as the neighborhoods grew older, the original buildings were often rebuilt for occupancies other than those originally intended. Many of the structures built on the vacant lots have a different floor plan. As you move out to the most recently developed edge of the metro area, balloon-frame and ordinary construction become less common. All the structures in the new developments are constructed with lightweight members; generally have similar occupancies, such as single-family houses; and many have the same floor plans.
Even if the same fire were to occur in each of these buildings, each building would perform differently. When preplanning these buildings, look at how these differences affect fire spread and resistance to collapse. Examining the construction features will give you a rough idea of how long you would be able to wage an interior attack before having to switch to a defensive operation. The time estimated for safely mounting interior operations would depend on the fire’s location (and how quickly it is found), the degree of fire spread on your arrival, and the information in your preplan. Your preplans should anticipate a situation in which the original building is fully involved as well as the more common one- or two-room fire.
ORDINARY CONSTRUCTION
Ordinary construction can be identified by the following characteristics: outside masonry, load-bearing walls with wooden floors and roof. In the original condition, the floors and the roof are supported by dimensional wood joists at or about two inches 2 12 inches. These joists reach from one outside bearing wall to the other. A telltale sign of ordinary construction is the header course of brick that appears about every seven courses on the outside walls. Sometimes these header courses can be seen only from the side exterior walls because the front face has been covered with an additional brick veneer or façade. You have to examine this during your preplanning, because buildings with lightweight components often look like ordinary construction. In typical ordinary construction, there is little room for the fire to travel vertically between the plaster and the outside brick walls. When fire starts in a room, it will breach the ceiling and burn horizontally in the ceiling joist bays until it finds a vertical path, such as a plumbing wall, to travel upward. If the ceiling above the fire room leads to the attic, the fire will extend vertically to the roof and horizontally underneath the roofline until it is extinguished or burns through.
Buildings in their original state with dimensional wood floor joists and roof supports are quite stable under fire conditions. They tend to keep the fire from spreading to nearby exposures unless windows are lined up between two buildings. If you are the first to arrive on the scene of a fire in a building of ordinary construction and two or more floors are heavily involved, request an extra alarm and maintain a defensive position to protect exposures until the fire in the main building can be knocked down with exterior streams. The fire may then be finished off with an interior operation if the building is stable.
Also, if companies have been on the scene and working inside for 20 minutes without extinguishment, all companies should be pulled back to a defensive position. Two floors of fire and 20 minutes of work time without success are two rules your preplan should cite as criteria for evacuating the structure and switching to a defensive position. Under these conditions, expect that the building will soon collapse (photos 1, 2).
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BALLOON FRAME
Exterior walls of balloon frame construction consist of 2- 2 4- inch or 2- 2 6-inch vertical members, called studs, which extend from the building’s foundation to the attic. The floor and roof are supported by a ledger board nailed across the studs. Fire can spread vertically from the basement to the attic through the space between the studs inside the wall, except where horizontal “headers” are framed into a wall for a window or a door. The wood framing and sills that connect from the interior room window through the outside wall stop vertical spread. One way to tell a balloon frame is by the age. If it is nonmasonary and looks 60 to 100 years old, it may be balloon frame. These buildings generally were built before the 1940s. An old-time front façade should also make you suspect it is a balloon frame (photo 3). When in doubt, consider it to be of balloon frame construction until it has been proven otherwise.
Fire can easily travel vertically through an outside wall. If you arrive on the scene with fire or smoke showing in the attic, consider that the fire started on a lower floor or in the basement. Start your search for the seat of the fire on the lowest possible floor. When you find this situation on arrival and must protect civilian egress from an upper floor, feel the plaster on the exterior walls with the back of your exposed wrist while ascending the stairs. If the plaster is hot, you will know that the fire is below you and traveling vertically. Balloon frames often have fire break out at some midpoint in the exterior wall. If asphalt siding seals this wall from the weather, the fire most likely will endanger an exposure because the asphalt siding burns quickly and it will be difficult to get a hoseline on it if the lead out already has been brought inside. Preplan for an exposure line to be placed between close exposures early in the operation.
Buildings of balloon frame and sometimes ordinary construction may be leaning or racked to one side or the other. Note this during preplanning. Many if not all of the connections between the building materials are under stresses that will only get worse when the fire exposes them. Even a very small fire can cause collapse quickly in a severely racked building. The more racked it is, the less fire it will take to make it fall. If it is not leaning, generally the criteria for defensive operations are two fully involved floors of fire on arrival or 20 minutes of interior work time without success.
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 (6) This building in the rehab zone was originally built using ordinary construction. During the renovation, the front brick was stripped off. |
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PLATFORM FRAME
These buildings are the wood-frame replacements for balloon-frame construction. They are built as complete floors and are finished with a plywood floor deck before the next set of walls is erected on top. Platform construction can be seen as some type of multilevel single-family home or smaller multifamily apartment buildings; they often have some brick as a cosmetic veneer showing on the front exposure. Fire that penetrates a drywall ceiling will spread horizontally between the overhead ceiling joists and should be stopped by a top plate nailed to the top of the studs to support the floor joists or roof structure above. This inherent fire stopping provided by a top plate (at each floor in platform-frame construction) is eliminated when a portion of the top plate is cut away to allow ductwork, plumbing, or utility lines to run from floor to floor or from the top floor to the attic.
Traditional platform construction is still used today and can easily be confused with structures built of lightweight members. A traditional platform frame will stand much longer than a lightweight building. Knowing the difference between these two types of structures is important. If you know from your preplan that the building is of platform construction and not a lightweight building, you can expect that it will adhere to the 20-minute interior-work time rule unless more than two floors of fire are showing on arrival. Again, these two rules apply to a collapse in a platform frame.
Newly built platform-frame buildings can have two types of pitched roofs. The older ones, built in the 1960s through the 1970s, have low pitch roofs that often have nonusable attic space above the rooms. From the 1980s through the present, these buildings have been built with vaulted ceilings in the “living rooms,” which are used by occupants during the hours they are usually awake. Examples of living rooms would be a den or a kitchen.
Vaulted ceilings (photo 4) can be dangerous for firefighters because we are used to ceilings that rise only eight to 10 feet above our heads. Even though we are keeping low from the heat above us, we can still get a sense of the fire conditions above if the ceiling level is a normal height. If the ceiling is 15 or 20 feet above us, so are the heat and the fire. The fire could be rolling above us without our knowing it. Even if we raise our uncovered wrist while standing, we may be able to feel the heat only at the 10-foot level. If you determine in your preplanning that a building has tall ceilings, you would have to check conditions above your head when you get the fire duty. You can do this a couple of ways. You could send a quick stream of water from the hoseline to the ceiling and gauge the temperature when the water comes down. If it is very warm from the few seconds in the smoke or if it doesn’t come down at all because it has turned to steam, you have a problem. It is time to wash the ceiling in this tall room because fire is rolling above your head. Another way to check the overhead fire conditions is to stick a cool pike pole in the air for 10 seconds. If the metal hook comes down warm, it may be time to hit the ceiling with water. Structures with lightweight components can also have tall ceilings.
 (7) Here, the front brick has been put back and the new floor supports are in place. |
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 (8) The first-floor entrance. You can see the truss supporting the floors. This building can be deceiving because the floor is expected to be supported by 2- 2 12s and not a truss. |
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LIGHTWEIGHT CONSTRUCTION
This type of construction has been used since the late 1980s. The structure is basically built as a platform frame, but the floors and roof are supported by a truss or an I-joist system instead of the traditional 2- 2 12-inch dimension wood members. These trusses have little mass, which makes them easy to burn, and the small-gauge metal gusset plate connectors peel off when exposed to very little heat. When the fire breaks through the drywall ceiling of the fire room and starts burning in the truss, it will travel along the path of the truss, as it would in the case of traditional wood joists. It will also burn between the open webs of the first truss and expose other truss joists. All the truss joists will be exposed to heat and fire at once, and as soon as one of the trusses fails, the others may soon follow. This floor collapse can occur within five to 10 minutes, even with incipient fire conditions. This countdown starts when the fire starts, not five to 10 minutes after arrival on the scene. The floors in a lightweight frame can also be supported by I-beam joists. They are basically a 2- 2 4-inch top and bottom plate with a piece of 1/2-inch plywood placed vertically between them. They will burn through rapidly: They have so little mass that the fire will destroy the structural integrity in a couple of minutes.
Assume that newly built single-family houses and small multifamily apartment buildings are built with lightweight components until you know otherwise. This can be done through a prefire plan; companies should constantly familiarize themselves with their response districts and note the types of construction and structural members used in buildings under construction and renovation.
In older areas of the cities, you may find some lightweight structures built to look like ordinary and balloon-frame construction. Some have a brick façade on the front and vinyl siding on the other exterior sides. During the preplanning, explain to the crews that all members should look at as many sides as possible when arriving at the fire scene. If a building has brick on the front and vinyl on the sides, assume that it is newly built and probably has lightweight members inside (photo 5).
Some areas with older houses contain remodeled or rehabbed buildings that have a mix of old and new construction. These residences can be very deceiving; the old brick may have been stripped off the front, and lightweight components may be used as interior floor supports. The old brick is then replaced on the front façade to give it a trendy vintage look (photos 6, 7, 8).
The questions to ask when trying to ascertain whether a structure is made of lightweight components are the following:
Was the building constructed after the late 1980s?
Is the area in which it is located an older section of the community that is considered trendy and a desirable area in which to live? In other words, is this the “rehab zone”?
Was new floor space added to the building’s original plan, regardless of how old the original structure or addition is?
If you answer yes to any of these questions, the building may be at least partly constructed with lightweight components. New construction most likely would be built with a truss or I-joists. This is the quickest and most economical way to build if local codes allow it. Newly built government housing or housing subsidized by a government agency most certainly will be constructed with lightweight components. Structures in trendy areas with older housing generally will be rehabbed with truss joist floor supports, which is the most economical choice. Also, a single-family house that has added floor space probably contains these lightweight parts, including single-family houses that have dormers in a previously unlivable attic. A “dormered out” house could have a truss or I-joists supporting the entire first floor ceiling/second floor.
If you have not preplanned a building and are called to a fire in that structure, when you arrive on-scene, ask yourself the three questions listed above. If you answer yes to any one of them, examine the construction before committing firefighters to an interior attack. The key to doing this is to understand how fire and heat travel in open web truss joist supports. If you recognize that open web truss floor joists are present when you arrive, the construction of these joists will enable you to check the joists for fire. The easiest way to understand how fire spreads in the joists is to compare the truss area with a flat roof attic space (cockloft). An open web truss supporting a floor creates a loft similar to a cockloft. If you pull a ceiling as soon as you step inside the fire building, you will see the truss if one is there. Do this in an uninvolved section of the building where there is no smoke and where you can see the ceiling. It may be best to pull the ceiling on the lowest floor available and work up vertically from there. In this way, you will be able to determine if the floor the firefighters will have to walk on has truss joists and whether the joists have been exposed to fire (photos 9, 10, 11).
During preplanning, explain to your crews that checking the ceiling/floor joists should be done before the hose team gets too far inside. If the firefighter pulls ceiling and sees lightweight truss components, it will be evident that this portion, or possibly the entire building, contains these supports. This information must be communicated to the incident commander and all members on the fireground. If lightweight trusses are exposed to the fire, stop interior operations and pull your teams back to a defensive exterior position. A truss or I-beam joist system exposed to fire will collapse within five to 10 minutes.
Sometimes the inspection hole must be made on the ceiling of the fire floor—for example, in instances where the floor plan makes it necessary because there is no lower floor to enter or where you must protect civilians escaping from the fire. If you see smoke in the truss, it means fire and heat have already breached the ceiling in the fire room. Anytime you find a truss or I-joists that are not exposed to fire and decide to move deeper into the building on that floor, continue to pull ceiling at regular points and inspect the truss area for signs of fire, smoke, and heat. The time it takes your company to move deeper into the building gives the fire more time to breach the ceiling of the fire room and expose the truss loft above you head. If you must make the inspection hole on the fire floor and you find a truss in the ceiling above your head, consider if the floor on which you are standing is also supported by a truss. Does the floor feel weak or spongy? If so, it may be exposed to fire, and it is time to retreat so you can inspect the floor supports on which you are standing.
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 (12) This structure was originally built as a single-family house. Now, it should be considered a three-apartment unit. The rear porch provides a second way out of the second and attic floors. |
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OCCUPANCY
It is important when preplanning and sizing up on the fireground to determine the occupancy of the fire building. This information will give you an idea of whether the building has a floor plan with which you are familiar. The occupancy will tell you how many victims could be inside and where they may be found. Estimate that every bedroom has two occupants. A two-unit apartment building will have a different search pattern than that used for a single-family house. The single-family building most likely would have living rooms on the first floor and sleeping rooms on the second. A two-story multifamily structure would have two complete living units with both living and sleeping rooms on each floor.
In a multifamily apartment building, the work for the search crews is double that for the single-family house. This is true even if both the single-family and the two-flat structures have the same amount of floor space. With a two-flat building, you are working longer in adverse fire conditions because you have more rooms to negotiate through in dark fire conditions. If you normally arrive on the scene with minimum staffing, your preplanning should include a discussion of what it would take to get enough firefighters on the scene to search both floors in a timely manner.
The occupancy of a building can be deceiving. Single-family houses can look like two-flat structures, and vice versa. Older houses may have been remodeled into apartments before codes were passed to stop such practices; the structures may still be used as multifamily buildings under a “grandfather” exception in the building code. Buildings converted from a single-use to a multiuse occupancy tend to be older and usually are not located in the building renovation zone.
When you arrive on-scene, looking at as many sides of the building as possible can help you to determine the occupancy. Building codes mandate a second exit out of every separate residential living unit. This is a key preplan and fireground size-up consideration, and it applies even when the single-family house has been made into an apartment building. There must be a second way out of the second unit. A look at the rear or anywhere the second exit might be should tell you if the building is a single-family or a multifamily apartment building. If it is a two-story building and it looks like a two-flat structure but has a one-story rear porch, anticipate that it is a single-family house. With this observation, you have gone a long way in deciding where the bedrooms are and where the searches should be focused. If you are in a position on the fireground to determine if the building is a one- or two-family occupancy, radio this information to all on the fireground (photos 12, 13, 14).
There are a few exceptions to the conventional two-way-out rule—for example, an original unremodeled building that has less space than that stipulated for mandating the second means of egress or a structure that was built before any code existed. These buildings may have as much as 400 to 500 square feet on a floor. Sometimes a building at the back of a neighborhood lot, called a “coach house,” fits into one or both of these categories. Sometimes, these buildings may be two floors and legally “grandfathered” as two-family structures. During preplanning, note the locations of the bedrooms and where to place ladders for vent-enter-search/ladder rescues and vertical ventilation (photo 15).
There are times during preplanning when you come across a building the city has not yet caught up to with respect to enforcing the current building regulations. These buildings could have living areas, such as attics and basements, being used as sleeping areas instead. These rooms can be found in apartment buildings and single-family houses. Some indicators of this situation you can look for on the fireground and while preplanning include the presence of several mailboxes, extra gas service regulators, dormer additions to a pitched roof attic, additional basement entrances not in the original plan, and fire escapes (photo 16).
Demographics are also important when prefire planning. For example, neighborhoods with large immigrant populations commonly will have many large single-family homes that have been divided into multiple single-room occupancies. When arriving at a residential fire, look at the attic windows to see if this area is occupied. If the attic is tall enough to walk in and that window has an air conditioner in it and drapes or curtains on it, or if a thermal pane replacement window has been installed (which is a better window than normally would be found in such an unoccupied space), assume that the attic is occupied. If the rear of the building has a porch that extends to the attic so that it can be used as a second way out, consider that the attic is occupied. Again, finding any of these situations on the fireground should be radioed to the incident commander, who should notify all on the fireground.
 (13) A single-family occupancy. The one-story rear porch just above the rear window of the car tells us there is no second way out for a second-floor apartment |
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 (14) This two-unit apartment building has a two-story rear porch that provides a second way out for second-floor occupants. Both floors have living and sleeping rooms. |
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FLOOR PLAN
The rooms of a residence can be classified as “awake” rooms and “sleeping” rooms. Sleeping rooms are bedrooms and rooms such as living rooms and dens that have couches in them. Living rooms are all other areas in which we expect that there will be no sleeping persons. Regardless of your time of arrival on the scene of a residential fire, make searching the sleeping areas a high priority, because occupants, especially young children and the elderly, may be sleeping during daylight hours. If you are going to make sleeping rooms a primary search priority, consider the couches as sleeping areas. When conducting your primary search, expect to find victims in the sleeping areas and in the path of egress. On the way in, you may find victims who were overcome by smoke while trying to escape from the fire.
With some notable exceptions, such as Cape Code-style houses and new large suburban homes, bedrooms in residences tend to be grouped together. Again, prefire familiarization while on EMS runs will indicate if these exceptions exist in your district. In a one-story house, there is an “awake” and a “sleeping” side. If it is a two-story house, the bedrooms most likely would be on the second floor. Apartments have a complete set of bedrooms and living rooms on each floor. These points should be noted in the preplan. Primary search patterns should cover these areas as quickly as conditions allow.
While preplanning for bedroom locations, look at how you enter the building from the street. Older buildings tend to be narrow across the front and deep from front to back. The overall shape of the floor is rectangular, and the entrance doors are on the ends. The bedrooms are lined in a row on one side of the floor plan; the living areas are used as the hallway between them. Each bedroom exits into a living room, the kitchen, or the dining room. Newer floor plans will have the bedrooms within a circle of doors. The overall shape of each floor is square. All the bedroom doors lead to a short hallway, which then leads to the living rooms. The officer can use this hallway to monitor conditions while another member searches the bedrooms (Figures 1, 2).
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The bedroom itself has a floor plan. Furniture can normally be positioned in only a few ways. Almost all the bedrooms in one neighborhood most likely would be only of a few different sizes. If the room is small when the furniture is set down, the open floor shape would be a tight “U” or an “L” shape. The floor shape is created by the open space left after the furniture is in the room. If the room is larger, it would be a similar shape, but there would be more room between the furniture. This extra space will make searching more difficult because a firefighter may not be able to reach from one piece of furniture to another without going to a wall first for orientation. Parents with small children usually don’t place a crib under a window because the cold air from the outside may blow on the child. If the room is very small, the crib will be placed wherever it fits. Windows often will be on a wall opposite the door. This is a good point of reference for search and venting and would be a second way out if needed. Radiators and forced-air heat vent covers will be below the windowsill. Closet doors in the bedroom will open out toward you; most other doors in the building will open in away from you. Large walk-in closets in newer buildings can confuse firefighters into thinking they are bedrooms. Check the room you are entering before committing completely (see “Search Considerations” on page 68).
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Preplanning residences benefits engine company firefighters and those assigned to truck companies. Engine members familiar with floor plans of residences in their district will more accurately estimate the amount of hose needed to reach the fire as well as where to position themselves along the hoseline to maneuver it up stairways, down hallways, and around corners—obstacles not readily visible in heavy smoke. Truck company firefighters can use their preplanning familiarization to rapidly target sleeping areas and paths of egress—from the inside and outside of a dwelling.
By preplanning the one- to three-family buildings in your district, you can get all your members on the same page before arriving on the fireground. By preplanning, experienced members review and pass on their knowledge to the newer ones. It is a way to bring the entire company home at the end of the shift by ensuring communication and improving efficiency during changing fireground conditions.
 (15) This coach house may house two families. The attic also appears to be occupied, since there is an air conditioner in the left window on the third floor. |
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Search Considerations
Following are some considerations to keep in mind when searching a bedroom or other sleeping area and egress paths.
The bed will be the biggest piece of furniture in the bedroom and the most likely place to find a victim. When you sweep the bed during your search, ensure that at least one corner of the bed is covered with your hand. This is done to find out if the bed is a bunk bed and holds another person above your head. If the bed seems to be larger than a twin-size bed or if it seems to be unusually large for the room because you ran into it as soon as you entered the door, it is best to sweep all the way across it and from head to toe. You can feel if more than one person is sleeping in it.
The family may not be able to afford even a simple bunk bed and may have the children sleeping two or more to one bed. Sweep the floor below the edge of the bed from which a sleeping person would normally arise, which probably would be the side from which you entered. A person who can move a small distance before being overcome may roll off onto the floor in front of the bed in an attempt to escape the fire. As a safety measure, whenever you enter a bedroom, chock the door above the bottom hinge so that you will not get lost inside and you can pull the chock if conditions make it necessary for you to close the door. After searching the entire room, you will know you are exiting the same door when you reach the chock again.
Victims may be found sleeping on couches. Just as the bedrooms, the “awake” rooms have a common layout. The couches probably would be placed against a long wall or in a circle centered around a TV, table, or fireplace. As you do your EMS runs, note the layouts; you will probably notice some patterns. If you find a person when you sweep your hand across the couch, sweep the floor just below the edge of the couch. Another person able to move only far enough to fall off the couch could be there. In this area, you may also find a child who was being held by the occupant you found.
The path of egress often will have victims in it. Often when forcing entry, we find that even though the door seems to be open, it is blocked by something inside. Stick your hand around the back of the door to feel what it is. That block may be a person who couldn’t open the door from inside. In the path of egress, it’s good to sweep the area around the location in which you find a victim. If the overcome victim was carrying a child while running out of the room, the child would be next to the victim.
While on the way to the seat of the fire, the engine company may find a victim. If possible, hand the victim off to a truck member for the drag and continue to lead out. If there is no truck firefighter around, drag the victim out, leave him in safe hands, and continue the firefight.
Sometimes a victim will be found in the path of egress well after the fire has been extinguished. When this happens, the engine team may be saying that there was so much stuff in the building that it felt as if they were walking on bags of clothing. If you feel as if you are standing or kneeling on such a surface, check it out before moving forward.
JAMES MASON is a firefighter with the Chicago (IL) Fire Department. He has an associate’s degree in fire science from Chicago Citywide Colleges and has taught at the Quinn Fire Academy in Chicago.
