An Innovative, Cost-Effective Approach to Fire Safety

With the high price of fire suppression systems, the skyrocketing cost of insurance, and an overall industry focus on safety, utilization of fabric structures for storage and processing of biomass products is a cost-effective and practical solution.
By Chuck Auger | July 11, 2017

On an early November morning in 1999, a fast-spreading fire engulfed a Rubb Building Systems storage facility at the Merrill Marine Terminal in Portland, Maine. A stray spark caused hundreds of bales of scrap paper to ignite as fire swept through the 82-foot by 120-foot structure, one of four Rubb buildings at the terminal.

The fire vaporized the PVC membrane, allowing heat and smoke to escape, thereby preventing heat damage to the steel framework of the building. Fire personnel were able to fight the fire safely and effectively from outside the structure. Despite the severe fire, the structure was back in service with a new PVC membrane in less than a week after the severe fire.

After the event, Rubb Inc. client P.D. Merrill commented that any other building would have been a total loss.

This real life situation supports the fire performance testing and research done by Rubb Building Systems regarding fire safety and suppression in fabric-covered buildings.

The high price of fire suppression systems, along with the skyrocketing cost of insurance and overall industry focus on safety, especially fire safety, the utilization of fabric structures for storage and processing of biomass products is a cost-effective and practical solution.

The fire safety advantages of a fabric-covered building are fairly logical. Due in part to product familiarity and collected data, Rubb buildings are being used as the primary examples in this article; the performance of other fabric buildings may vary based on materials used in construction. The PVC cladding material (fabric) is woven to be fire retardant—it does not spread flame, contribute fuel or support combustion in a fire event. Once the internal building temperature reaches 400 degrees Fahrenheit, the material melts, thus venting the fire. The self-venting feature of the building membrane allows smoke, heat and combustible gases to exit the structure, thereby reducing the risk of flashover, property damage and injury. From a life safety standpoint, fires can be fought from the outside of the structure—fire personnel do not need to be put at risk to “vent” the roof.

In the Portland Harbor fire event, along with fire testing on framed, fabric structures done by Factory Mutual Research Corp., it was found that in a typical fire scenario, the alarm system was actuated prior to burn-through. However, it is questionable whether a sprinkler system would actually be effective against a flame, as fabric burn-though occurs quickly. Because Rubb utilizes hot-dipped galvanized steel, no structural damage occurs to the steel frame, as the temperature is never high enough to damage it. Conversely, in a conventional, metal-clad or wood building, the interior temperature would be expected to reach high enough levels to create structural failure. An aluminum-framed fabric building would also most likely suffer structural damage, as the heat would irreparably damage the aluminum.

In the aviation industry, specifically in regard to fabric-clad hangars, full-scale flame testing has shown that due to the aforementioned self-venting, sprinkler systems are no longer required in many instances. Fabric-covered, steel-framed hangars now often only require foam suppression systems to protect the aircraft, a significant cost savings.

The fire safety benefits of a fabric building are real:  lower fire suppression costs and requirements, less down time in case of a fire event (the Portland building was back in business in a week), potential insurance savings and definite life safety advantages.

The operational benefits of a fabric building are also real: little or no maintenance, often lower initial cost, lower energy costs, and translucent roof and flexible design features, including relocateability. As the fabric building industry continues to innovate and improve, the benefits of using these structures in the biomass industry are very real.

Author: Chuck Auger
Marketing Manager, Rubb Building Systems