BY DAN SHAW
 1 Photos by author. |
Building industry practices have a fundamental impact on our ability to perform on the fireground. The relationship between the building industry and the fire service is well documented and demonstrated in our nation on a daily basis. Firefighting strategies may differ across the country, but all firefighters will invariably battle fires in occupied structures. Construction materials and methods and the manner in which builders complete their work significantly impact our daily operations. According to the National Fire Protection Association (NFPA) report on 2004 firefighter fatalities, the category of “caught/trapped” accounted for 34 percent of fatalities among career firefighters and 3 percent among volunteer firefighters. This calculates to a total of 12 out of 103 who died in the line of duty because of some type of failure of the building system.
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Unfortunately, the impact the building industry has on fire service operations is ancillary to the need to construct buildings within strict codes set by governing agencies. Therefore, it is pertinent that the fire service be kept informed of the most recent codes, building techniques, and materials in use.
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A relatively new component used in limited commercial applications is Hi-Impact® Lexan® Wallboard (photos 1-3). This type of wallboard is reinforced with a sheet of Lexan® on the rear of the panel (Figure 1). This could be detrimental to a firefighter attempting to escape from a burning structure. Lexan® has incredible strength and resists many of the techniques firefighters use for emergency egress or ingress. Because this wallboard is expensive, it has limited use. It’s estimated that less than .0003 percent of the total gypsum wallboard sold in 2004 was of this type.
USES AND CHARACTERISTICS
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Hi-Impact® Lexan® reinforced gypsum wallboard is typically used to separate commercial occupancies and deter potential perpetrators from kicking through the wall of the adjoining occupancy. The wallboard is composed of 5⁄8-inch normal gypsum with a layer of Lexan® laminated to the back of the panel. Four thicknesses of the Lexan® are used.
Eighty-millimeter-thick Lexan® wallboard sheets laminated to the rear of the wallboard panel were used during tests we performed. To ensure that the tests were conducted using the wallboard in its true application, each gypsum panel was affixed according to the manufacturer’s recommendations.
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Each wall was constructed on 35⁄8-inch metal studs spaced 16 inches on center (photo 4). The 8-foot × 8-foot wall was constructed in a 13-foot × 8 foot, 6-inch room in the Fairfax County Fire and Rescue Academy burn building. One side of the wall was constructed with Hi-Impact® Lexan® wallboard on the lower portion and 5⁄8-inch gypsum wallboard on the upper portion. This side is referred to as the “Mayday” side (photo 5), to simulate situations in which a firefighter chooses to egress because of escalating and untenable conditions of a fire room.
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The other side of the wall was constructed of 5⁄8-inch gypsum wallboard on the upper and lower portions. This side is referred to as the “RIT” side (photo 6), to simulate the conditions a rapid intervention team (RIT) faces when attempting to enter a fire room to make a rescue from the adjoining room. Note: Both boards look the same on the outside; the Lexan® is covered by 5⁄8-inch gypsum board.
TESTING PROCEDURES
Five tests were conducted: one control test under no fire conditions, two egress tests from the fire side, and two ingress tests from the nonfire side. These tests were chosen to simulate situations firefighters encounter in structures where Hi Impact® Lexan® gypsum wallboard is used.
• Control test. This test was conducted under nofire conditions on the Mayday side. The wallboard was mounted in the appropriate commercial application, 35⁄8-inch metal studs 16 inches on center. The Hi-Impact® Lexan® wallboard was on the lower portion; 5⁄8-inch gypsum on the upper portion.
• Fire Test 1. The time parameter was selected based on National Fire Protection Association (NFPA) 1710, Standard for the Organization and Deployment of Fire Suppression Operations, Emergency Medical Operations, and Special Operations to the Public by Career Fire Departments, 2001, which states that the first-due engine at 80 percent of the suppression calls should arrive within four minutes. We determined that if it takes four minutes to arrive on the scene, it would take an estimated six minutes to deploy a handline and begin firefighting. Therefore, our first fire test subjected the wallboard to six minutes of untenable fire conditions.
After six minutes, the fire was extinguished and the room was ventilated. The test was conducted in clear conditions; we were testing the degrading effects fire would have on the wallboard, not the psychological/physical impact of fire conditions on the firefighter. After ventilation, the Mayday firefighter began the emergency egress procedure. After the Mayday firefighter completed the maneuver, the RIT began its ingress operation.
• Fire Test 2. We consulted the NFPA 1710 standard again, particularly the portion concerning the arrival of the first alarm. The standard states that the entire first alarm should arrive within eight minutes. Therefore, our second fire test subjected the wallboard to eight minutes of fire.
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All tests were timed to evaluate how the emergency egress maneuver would be affected by fire in various timed sequences. Both a firefighter calling a Mayday and the RIT performing a rescue are ultimately concerned with time, since this is the determining factor of the air supply.
MAYDAY PROCEDURE
As mentioned before, the side exposed to the direct effects of the fire was referred to as the Mayday side of the wall, based on the criterion that a firefighter confronted with heavy fire conditions in this room, and who had no other means of egress, would appropriately call a Mayday. To ensure fireground reality and test continuity, we set the following conditions:
The exit hole was 24 inches high. This measurement was based on a six-foot firefighter weighing 200 pounds lying on his stomach (photo 7). This is the position a firefighter would retreat to if confronted with the fire conditions created in the burn building. Twenty-four inches is also roughly the height of the six-foot firefighter on his knees striking the wall with a halligan.
The Mayday firefighter had a halligan bar to aid in the emergency egress. On the East Coast, many fire departments carry this tool to most incidents because of the vast array of options it offers. Since a firefighter initially entering a structure can carry only what he deems a necessity for most situations encountered, the halligan bar was chosen for the emergency egress test.
To ensure continuity throughout the test, the same emergency egress technique was used. Based on the construction of the wallboard and fireground experiences, we found the following method to be the most efficient:
The fork end of the halligan bar was used to forcefully puncture holes through the highest portion of the wall, cutting through the gypsum portion and Lexan® sheet. For the Mayday firefighter, we estimated a 24-inch-high section would be sufficient for emergency egress. This maneuver is similar to that used to remove a windshield with a pickhead ax.
After making the punctures horizontally between the studs at the 24-inch height, the adz (point) of the halligan was used to enter the punctured line vertically. The halligan was then used to pull the gypsum portion of wallboard down toward the ground, removing the gypsum wallboard and exposing the Lexan® backing.
If the Lexan® portion was not fully punctured from the intial action, the process was repeated with the halligan. The fork end of the halligan was used to forcefully puncture a horizontal line between the studs through the Lexan®. This served as the top of the hole the Mayday firefighter used to perform the emergency egress.
Once the top line was clearly punctured, the halligan was turned vertically and the fork end inserted into the middle of the Lexan® between the studs. Downward pressure was then applied to the top portion of the halligan, and the Lexan® was torn apart in the middle, exposing a door-like entrance.
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The halligan or a well-placed firefighting boot was used to kick through the newly made hole in the Lexan® and break out the gypsum wallboard on the opposite side. To complete the emergency egress maneuver, the Lexan® sheet was forcefully pulled toward the firefighter, and his body was forced through the hole to the safe haven on the opposite side (photo 8).
RIT PROCEDURE
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The RIT is afforded the opportunity to gather an assorted cache of tools appropriate for the conditions the team faces in its operations. The tools typically available to the RIT (photo 9) include a circular saw with carbide blade, a 10-pound sledgehammer, a six-foot drywall hook, a pickhead ax, a flathead ax, a short-handled hook, and a halligan bar. Since the RIT is focused on rapidly gaining access, saws would facilitate this mission. Based on the manufacturer’s recommendations for site cutting, we used a circular saw and chain saw (not shown in photo 9), both with a carbide tip blade/chain.
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During the RIT procedure, the RIT firefighter encountered the reverse of what the Mayday firefighter met. He encountered normal 5⁄8-inch gypsum wallboard followed by Lexan® backing affixed to the rear of the 5⁄8-inch Hi-Impact® Lexan® wallboard (photo 10). It was assumed that the RIT would bring a proper assortment of tools following vigilant preplanning and consultation with the Mayday firefighter. Based on our fire test results, the most efficient method for RIT’s breaching a Hi-Impact® wall was as follows:
• Remove the 5⁄8-inch gypsum wallboard using conventional techniques-for example, kicking out the wall, using the adz portion of the halligan to puncture and pull down the wall, or using a short hook to puncture and pull down the wall.
• The RIT was faced with the rear of the 80-mil Lexan® laminated to the gypsum wallboard. The RIT took a circular saw or chain saw with a carbide tip equipped blade/chain and made a horizontal cut from stud to stud (16 inches) at any point on the highest portion of the wall.
• Much like ventilation cuts on a roof, the RIT made two vertical cuts from the top horizontal cut to the ground in between the studs. The Lexan® wallboard fell from the remaining portion of the wall, exposing a 4 foot × 16-inch hole.
• If the RIT deemed a larger hole was necessary, the members cut across the metal studs, making a 32-inch-wide hole.
SUMMARY OF TESTS
As noted, Hi-Impact® Lexan® wallboard is designed to make it more difficult for a perpetrator to gain access to an occupancy. This wallboard poses a significant hazard if emergency egress is warranted. The need to be able to mitigate this new product precipitated our testing of this wallboard under conditions we would face.
By conducting nonfire and several fire tests, we found the best method for achieving an emergency egress or ingress. The following tips and tricks will aid in conducting a successful egress or ingress when this wallboard is present.
Mayday Activation
• The multiple functions and capabilities offered by the halligan show how valuable this tool is not only for normal firefighting operations but also for Mayday/RIT operations.
• To prevent a hand/forearm injury while using the emergency egress technique, hold the halligan bar on the shaft with both hands. This will prevent jamming the wrist if you inadvertently strike a stud or solid portion of the wall.
• The Lexan® proved to be harder to defeat when subjected to fire conditions. It began to delaminate; the heat made the Lexan® “sticky,” demanding more effort to puncture through with the halligan bar.
• The resounding lesson in this test is how important preplanning is for every member of the fire service. A firefighter unaware of the presence of Lexan® trying to attempt an emergency egress will be unfortunately surprised and possibly overmatched. You must know your buildings.
• If proper preplanning is done and a firefighter encounters the Hi-Impact® Lexan® wallboard during a Mayday situation, an alternate maneuver is available. Assuming the wallboard is mounted in the prescribed method (only on the lower half of the eight-foot wall in a horizontal fashion), you can use traditional breaching methods-i.e., any tool, foot, or fist, to breach the upper four-foot section of wall. According to the manufacturer’s recommended assembly directions, the top four-foot portion should be normal gypsum wallboard on both sides of the wall. Both sections are much easier to puncture if conditions warrant.
It is best to remove any possible entanglements from your gear prior to passing through the wall after making the hole in the Lexan®. The Lexan® on the rear of the wallboard might be jagged and tear your personal protective equipment and cause materials hanging from your gear, such as unclipped waist straps, to become entangled.
RIT Operations
• When the wallboard was subjected to fire conditions, the RIT side began to emit a pressurized thick, black smoke, comparable to that in a fire involving a petroleum product.
• The chain saw proved to be more effective in the emergency ingress than the rotary saw. The chain saw was easier to manage; the rotary saw subjected the firefighter to a harsh gyroscopic effect, regardless of inboard or outboard position.
• Depending on the size of the structure and the level of ventilation taking place, it may be necessary to use electric saws because of the volume of smoke emitted from the wallboard. Additionally, it is vital that you start your saws before entering the structure, ensuring they are properly warmed up. A tense, hot, smoke-filled environment is not the place to discover that your saw will not start.
In the fire service, we face the unorthodox choice of life or death when dealing with new and innovative building construction products for the first time in a fire situation. This choice demands that we be informed about and prepared for these products so we can defeat their adverse inherent qualities in the quickest and most efficient manner,
Since it is not possible for every fire service organization to test the Hi-Impact® Lexan® wallboard, we are sharing the information we gathered and urge that fire service members attempt to identify structures with this type of wallboard in their area. ■
Author’s note: Thanks to National Gypsum, particularly David Drummond, for donating the materials for these tests . Thanks also to the support team that conducted this test: the Fairfax County Fire and Rescue Training Academy staff, Captain II Dave Brooks, Captain I John Walser, Lieutenant Scott Kraut, and Firefighters Chris Blair and Bob Seward.
■ DAN SHAW, a 14-year-plus veteran of the fire service, is a lieutenant with the Fairfax County (VA) Fire and Rescue Department. He is also a field instructor for the University of Maryland Fire and Rescue Institute in College Park, Maryland. He was a H.O.T. Aerial Company Operations instructor at FDIC East.
