New Construction Trends Give Rise to Innovative Fire Strategy
Fire resistant building materials, well-located sprinkler heads, alarm systems, and fire prevention education combined and incorporated in a new, low-rise housing project in the heart of a high fire incident area, are the keys to successful life and property loss prevention.
Lightweight steel framing construction in low-rise housing may prove to be a factor in reducing structural damage during a fire situation by providing the major firematic impact—the confinement of fire to the area of origin.
Of paramount importance in the construction features of these buildings is the lack of combustible material in concealed spaces. Fire that does find its way into voids (such as pipe recesses, cocklofts, walls, soffits, etc.) will not be nourished by the usual wood studs, lath, and other combustible surfaces. We may find fire in the cockloft, but we should not be confronted with a cockloft fire.
This construction is already in use in an inner city community in Brooklyn, NY.
Examining the construction more closely, we find that the lightweight galvanized steel framing of each level is erected on a poured concrete deck separating each floor. This decking is 2 1/2-inch, 3,000 psi concrete on corrugated steel. This assembly is supported by 9 1/4-inch steel joists spaced 24 inches on center. These joists, as well as the other framing members, have been fire tested by Ohio State University and have been accepted for use by the U.S. Department of Housing and Urban Development (HUD), the Federal Housing Administration and model building codes nationwide.
The only spaces located below grade in these low-rise structures are for the heating plant and the compactor room. The space heating is via hot water baseboard convectors supplied by two gas-fired boilers. The domestic hot water is supplied by a separate, residential-type gas heater also located in the boiler room. The compactor room is equipped with standard 165° F sprinkler heads. The compactor shaft system is equipped with on-off, 135°F heads. Two are located in the compactor machinery, and others are in the chute itself at each floor level.
Early in the construction, one structure collapsed under the weight of newly poured concrete. This gave rise to questions of stability. Some of the answers to these questions included an increased quality control of each construction phase and to insure the proper bracing of the framing. Panelization, which is the prefabrication of exterior wall sections in the factory, allowed for more exacting standards, including the spot welding of framing members, and assisted in increasing stability. Interior wall framing was fastened together by screws at the site. The required bracing was welded in place.
The exterior walls are sheathed with a ⅝-inch, water-resistant, fire-rated, gypsum board. This sheathing is affixed to the metal framework by screws and then covered with a brick veneer. The interior walls that separate apartments or border on the public hall are covered with a double layer of ⅝-inch, fire-rated Sheetrock. The ceilings of the public hall are similarly protected. Additionally, the walls of the public hall also include a layer of 14-gauge sheet metal. The partitions and ceilings within the apartments are covered with a single layer of ⅝-inch Sheetrock. The ceilings of the top floor apartments also have a double layer of ⅝-inch Sheetrock. This provides a substantial fire barrier to the attic space but also allows for an easy opening-up and examination for fire extension and extinguishment. Examination of the cockloft will reveal a dividing partition from the top of the ceiling joists to the roof ridge covered with ⅝-inch Sheetrock, double layered on one side and a single layer on the other. The pre-engineered roof trusses are not directly protected so the element of failure under high heat conditions must be considered.
We must realize that any structure exposed to a fire of great intensity for a substantial period of time will probably fail, especially when trusses are involved.
As professionals, we have to estimate the possible fire intensity based on fireload and the speed and capability of our firefighting forces.
Using this reasoning to analyze the fire-containment capabilities of these low-rise structures, we can establish many important factors:
- First, the typical residential fireload, especially for the apartment dweller, would not approximate that of commercial or industrial occupancies.
- Second, the construction features of these buildings should contain the common mattress, sofa, or kitchen fire long enough to allow fire units to attack before the fire extends to adjoining apartments.
- Third, the relatively small size of the fire area should be handled by the first arriving unit with one interior handline. The need for an interior attack is stressed because there is a great temptation to put water on visible fire from the outside of the building. This approach would hamper the life-saving efforts of the other firefighters and endanger occupants not in the immediate fire area by pushing the fire deeper into the structure. It might also entice later-arriving units to operate similarly, thereby neglecting the more efficient interior attack.
- Reaching the roof itself, we find the only combustible elements used in this low-rise construction. On top of a layer of 1/2-inch, water-resistant, fire-rated, gypsum board, which is supported by the trusses, is a layer of wood sheathing. The sheathing provides a nailing surface for the roof shingles.
- A hard-wire, a/c powered, ionization-type smoke detector is installed within each apartment and in the public hall.
- A local, audible alarm signal is activated by any smoke detector.
- A manual fire alarm pull box, located on each floor, will sound the interior alarm bell. This bell also will be sounded when any sprinkler head is fused. Standard, 165° F pendant-type heads are located on each floor in the public hall. There is also a head in each apartment just inside the entrance door. Due to the alarms, the tenants should be aware of any fire problem. However, lacking a supervised system (central station connection), delays in notification of the fire department may occur. All tenants and employees are instructed to transmit the alarm to the fire department upon hearing any fire signal—but experience has shown that collective responsibility often leads to non-compliance.
Examining all the features of these buildings for the purpose of pre-fire planning reveals some unique and some common problems associated with residential buildings. As is usually the case, the most imminent life hazard is anyone trapped within the fire apartment. Fires originating in the kitchen or living room would trap any victims in the bedroom or bathroom. The sprinkler head in the apartment would probably fuse and protect the apartment door and ultimately the public hall. However, it would have little effect on the bulk of the fire in the apartment. Sprinklers used in this fashion are usually compromises between municipal building officials and the building industry in lieu of secondary means of egress. The sprinklers are an attempt to maintain the integrity of the exit facilities for the occupants under fire conditions. Housing of this type, built with the aid of funds from HUD, can probably be found in any city of the country.
Strategies and tactics
The strategy employed for fires in these apartments is not complicated. The need to place the hoseline between the fire and the potential victims is consistent with most fire operations. The fact that this structure resembles both the two-story, private dwelling with a gable-type, peaked roof and the very hot, contained fire of the fireproof housing project apartment, suggests that the tactics employed would be a combination of those used therein.
Considering all these major factors, a philosophy of attack can be established:
- The possibility of occupants
- trapped in the immediate fire area requires that a fast, interior attack on the fire be combined with a simultaneous search and rescue procedure;
- The confined nature of the fire, in the early stages, allows the first arriving engine and ladder companies to be self sufficient in these operations.
The following tactics were developed from extensive pre-fire planning considering both the physical characteristics of these buildings and the response of two firefighting units of fouror five members each:
- The first arriving pumper would stop as close to the building entrance as possible.
- After estimating the distance to the building entrance, firefighters determine how much hose is needed to reach the furthest apartment. This hose length estimation is made rather
- simple due to the central location of the stairwell.
- Two, 50-foot lengths of hose to cover any apartment plus one additional length to reach the third floor should be sufficient inside the building. This would allow a line being used on a first floor fire to be quickly retracted and moved to another floor to extinguish any fire extension. Also, the elimination of a great excess of hose makes the operation smoother and more efficient by reducing kinks, friction loss, and the possibility of burst lengths because of lower engine pressures.
- At this point, the motor-pump operator (MPO) would drive to the nearest hydrant or other water source.
- If the hydrant test is satisfactory, the MPO would dump the booster (supply the fire forces with the pumper’s water tank) while connecting the
- pumper to the hydrant. This would give a few minutes of immediate water while he completes his hookup. (The MPO must always inform the men on the line when they are working on booster water to avoid an over-aggressive attack. When the hookup is completed, the MPO should again notify the nozzle team that they have a positive water supply.)
- The first arriving ladder unit or second pumper with laddering capability would commence a two-fold attack. The officer and one or two men would go to the apartment door to perform forcible entry and search, while the outside team would ladder the building for rescue and venting. The formidable nature of the entrance would suggest a need for training in lock-pulling techniques as well as conventional forcible entry (see articles on forcible entry beginning with the May issue). Spreading the steel door buck (frame) is made more difficult by the double layer of Sheetrock and the welded panel of sheet metal. This would also hinder a breach alongside the buck in order to reach inside and unlock the door. Double-key cylinders and multiple locks also increase entry problems. Most locks added by tenants are surface mounted rather than mortised, and with some training, the cylinders can be pulled and the lock defeated.
- If the unit is aerial equipped, the chauffeur should setup where he can best cover the fire area. This would not preclude the use of portable ladders, especially if the fire is in a rear apartment. The use of the portable ladder by the outside team is a key element in
- the attack strategy. Testing the buildings in training drills showed the 24 or 26-foot extension ladder to be the one used for all operations. It will reach the third floor sill comfortably and, when bedded, can be set properly at the second floor sill. Anything larger is unwieldy and difficult to position. This pre-determination of a specific ladder for all operations reduces confusion, especially when the fire floor is not immediately apparent.
- The next obstacle, the continuous, steel, picket fence, required the fabrication of a special device. A three-foot long piece of 4 X 4-inch lumber was partially drilled out to match the picket spacing. This device is placed on the pickets and the ladder is slid over it to get to the back of the building.
- Once in the rear, the members can remove any victims showing at the windows or vent the bedroom window and make a search. Ideally, venting the fire room should be coordinated with the interior operations.
- Portable radios have greatly increased the efficiency of operations. When the interior attack team has water in the line and the door is opened, they can contact the members in the rear to begin horizontal venting behind the fire. This prevents the premature acceleration of the fire and increases chances of survival for the occupants.
- Another use of the radio is to contact the member assigned to locate the sprinkler control valve. Ordering the valve closed as the attack commences and the fire is under our control will assist the operation greatly.
- Any additional units arriving on the scene can augment the operation by
- stretching a precautionary back-up line, assisting with rescue efforts, and searching the exposed areas for fire extension and victims. When possible, entry to the adjoining apartments can be made with outside ladders to minimize damage.
- If extensive delay is experienced in entering the fire apartment, additional units could attempt a breach from an adjoining apartment or enter the adjoining apartment from a window or the entrance door. Once inside, firefighters would locate the common wall between the apartments. For these buildings, it is located in the bedroom wall closet. Punching a hole low to the floor may allow firefighters to enter and search a room not fully involved with fire. Victims pulled into the adjoining apartment would have a better chance for survival.
- Roof operations are kept to a minimum due to the pitch and the height. Venting the skylight would be of value to the interior forces but secure footing is a must in this operation. Cutting the roof would rarely be required. Substantial fire in the cockloft is not expected and examination can be performed via a scuttle hatch or by pulling the ceilings.
A coordinated attack, designed specifically for these structures, will result in:
- Rapid accounting for human life,
- A quick knockdown, control and extinguishment,
- Reduced possibility of fire extension to major-alarm proportions and the resultant heavy life and property losses.
Bushwick II is a renaissance of a residential community literally rising from the ashes and rubble of the chaos that prevailed for the past two decades in Brooklyn, NY. The groupings of three-story, brick dwellings with their new landscaping and playgrounds appear out of place in this inner-city setting. Directly across the street from this new development, the burnt out shells and partially occupied frame dwellings Bushwick II is replacing can still be observed.
Low-rise, public housing is not a new concept and neither is the lightweight steel framing system of construction. What is unique is the combination of these two elements. The original development consists of 50 buildings, each containing 12 apartment units. These 600 family units are expected to be followed by 300 more, making an impact on the community.
The low-rise concept of housing seeks to avoid the population density problems associated with previous, multi-storied, project-type housing. The buildings are spread liberally around the block area and are connected by a six-foot, steel, picket fence to prevent unlawful access to the grounds within. The grounds include open areas, parking facilities, and recreational equipment for the residents.
Guidelines for residency have been mandated to recreate the ethnic proportions existing prior to the devastion of the neighborhood. Similarly, applicants are drawn from different financial levels. Approximately 5% of the units are earmarked and equipped for the handicapped. These buildings are readily identified by responding fire companies by the ramps leading to the main entrance. The units for the handicapped are restricted to the first floor where three of the four apartments are designed to accommodate wheelchair-ridden persons.
Inherently, the construction features of this project should make firefighting operations less arduous and reduce structural damage to the building. However, this aspect should not overshadow the efforts of the housing management to promote fire prevention. The elimination of fire incidents is philosophically paramount to effective firefighting procedures. To this end, orientations are arranged for new tenants. They are instructed in proper use of compactors and the handling of rubbish in general. Tenant patrols are organized to supplement security measures provided by the management. Building committees are also formed to channel information to tenants, provide for lobby sitters, and generally promote interaction among the residents.
These measures hope to provide a more family-like atmosphere and inculcate pride and interest. Ultimately, this will reduce the major causes of accidental fire and also eliminate most conditions leading to deliberate firesetting. Arson derived from despair and frustration is less likely to breed where people are happy and content and where the ironic spector of being relocated in a Red Cross shelter or hotel exists.