Life Safety

Fire Reduces Five-Story Building to Ash in Less Than 3 Hours

Wind gusts of 15 – 20 mph swept over 90 con­struc­tion workers as they labored dili­gent­ly on a five-story, wood framed, 396-unit building in historic and diverse Montrose, Texas. The structure was the $50 million upscale Axis apartment complex. At 12:30 p.m., on that quiet March day in 2014, a small fire was reported on the roof of the Axis. Welders working on the roof attempted to put the fire out. But the high winds made it to impos­si­ble to control the fire. Soon nearly 200 fire­fight­ers and 80 pieces of emergency equipment responded to the five-alarm fire. Regret­tably, the fire quickly spread through the wood-framed building. The black smoke blinded the terrified men and women on the job site. The workers were forced to flee the complex. One con­struc­tion worker was trapped on a third story balcony as the flames whirled around him. For­tu­nate­ly, he was rescued by ladder just seconds before the flames would have engulfed him. Thank­ful­ly, no con­struc­tion workers or fire­fight­ers were hurt. At 2:56 pm, the fire was under control. Trag­i­cal­ly, in less than three hours, the luxurious apartment complex was reduced to ashes; just months before it was to open in June.

For years, wood con­struc­tion has been the standard for both res­i­den­tial and com­mer­cial buildings. Wood is a faster, easier, and less expensive con­struc­tion material than steel and masonry. However, wood-framed, and worse yet, engi­neered-wood buildings, are inher­ent­ly more dangerous under fire con­di­tions than those built with steel and masonry. In fact, a study by the National Fire Pro­tec­tion Asso­ci­a­tion documents that engi­neered- wood burns quicker and fails faster than cut lumber. Steel and masonry are not com­bustible, so fire spreads slower than either cut or engi­neered wood built buildings. However, steel can soften and bend, unlike masonry. Another downside to both steel and masonry walls is they lack the thermal per­for­mance required by the Inter­na­tion­al Res­i­den­tial Code (IRC) and Inter­na­tion­al Building Code (IBC) and so typically require insu­la­tion. Although wood con­struc­tion is very common, concerns about fire safety are causing designers and archi­tects to often consider alter­na­tive materials in wall con­struc­tion, like masonry, steel, or even better insulated concrete blocks (ICB).

When exposed to fire, insulated concrete blocks (ICB) limit the spread of flames. In addition, ICBs do not burn, bend or soften like steel. Insulated concrete blocks also meet the thermal per­for­mance required by the Inter­na­tion­al Res­i­den­tial Code (IRC) and Inter­na­tion­al Building Code (IBC) without addi­tion­al insu­la­tion. In summary ICB’s are capable of achieving fire ratings of up to four hours, prior to any finishes being applied. A four hour rating means a wall’s assem­blies will stay intact once exposed to fire for four hours. Compare this to the complete destruc­tion, in less than three hours, of the wood-framed Axis building! The exterior of a building con­struct­ed with insulated concrete blocks is identical to a wood-frame building once con­struc­tion is complete. However, fire behaves dif­fer­ent­ly in ICB than wood frame buildings. Buildings con­struct­ed with ICB have fewer empty spaces (cavities between struc­tur­al members) for fire to spread, and the insu­la­tion in ICB’s does not burn. Therefore, fire spreads slower in buildings con­struct­ed with ICB than wood.

Bautex Wall System Insulated Concrete Blocks Meet and Exceed Indus­try’s Standard for Fire Resistance

Exterior and interior walls of res­i­den­tial and com­mer­cial buildings can utilize the Bautex Wall System insulated concrete blocks.The Bautex Blocks have an ASTM E119 fire rating of four hours (two times the two-hour require­ment), and an ASTM E84 published values for flame speed of zero and smoke devel­op­ment of twenty. Because the Blocks meet the ASTM E84 and NFPA 286 they essen­tial­ly meet the NFPA 101 code. Bautex Wall System is highly fire resistant. They are also energy efficient, wind and moisture resistant and deliver sound reduction. When it comes to fire resis­tance, Bautex Blocks provide the maximum safety available in today’s choices of wall assembly materials. 

Fire quickly spreads in buildings con­struct­ed of wood.The Axis apartment building is a horrible example of how quickly a building con­struct­ed with wood can burn to the ground. Utilizing insulated concrete blocks that exceed indus­try’s standard for fire resis­tance, like the Bautex Blocks, will create a safer, more fire resistant structure than buildings con­struct­ed with wood.

ASTM E119 estab­lish­es a wall assembly’s ability to stop a fire from spreading. 

The ULC-S101 applies specif­i­cal­ly to the testing of material with fire and is unique to walls and ceilings.

ASTM E84 – Surface Burning Char­ac­ter­is­tics of Building Materials. The purpose of the method is to determine the relative burning behavior of the material by observing its flame spread.

The NFPA 101 is the only document that covers life safety in both new and existing struc­tures with pro­vi­sions for all types of dwellings, egress require­ments, fire pro­tec­tion features, emergency lighting, sprinkler systems, alarms, smoke barriers, and special hazard protection.