MILITARY ROOFING SECRETS How SPF Roof Systems Work For Some Of America's Toughest Customers Historians note that, without the development of nylon, the Allies may well have lost World War II. Today, another synthetic product, spray polyurethane foam (SPF), is contributing to the effective operations of the United States Military. T his article examines the use and benefits of SPF as a roofing material on U.S. Military bases throughout the United States and the world. Part I offers information on SPF benefits and performance, while Part II, which appears in the November ‘96 Issue of ROOFER Magazine, profiles several military bases that have installed and benefited from SPF roofing systems. Background Back in the 1970s, the military first began discovering the benefits of SPF, a roofing option suitable for almost any type of structure, in virtually any climate. It saw that SPF provided more than a physical barrier between ceiling and sky. When applied, coated, and maintained properly, it insulates, resists high winds, and prevents leaks. Furthermore, it features a life expectancy ranging from 10 to 40 years or more - depending on whom you talk to. These factors, and others, have led to a number of military installations over the years. The Benefits Of SPF Roofing Systems What is SPF roofing, and how does it work? SPF is a urethane polymer that sprays on as a fluid. Upon application, this fluid expands to form a foam that cures quickly, creating a seamless, self-flashing, monolithic roof surface that bonds to virtually any roof substrate. This bonding has two key benefits. First, it eliminates the need for metal fasteners that can cause energy-wasting thermal bridging. Second, it provides excellent wind uplift resistance. As stated in the UL file NC554, "Based on comparison of performance, the application of SPF did provide an enhancement of the uplift capability of the BUR Roof...The direct application of SPF to steel decks and plywood decks demonstrated uplift load resistance up to the capability of the test equipment to develop load (160-165psf) without any sign of delamination or other damage to the foam." SPF is also insulative by nature, boasting the highest R value of any readily available insulation in the marketplace. Many companies and organizations have reported savings of up to 30% on their heating and cooling bills after installing an SPF roofing system. According to a presentation prepared in 1993 by Sam Cohen, Project Management Supervisor, Engineering and Design Services at Texas A & M University's Physical Plant Department, "(we) monitored energy savings on 27 different buildings that had received an (SPF) roof from 1980 to 1984. The results were astounding. TAMU was able to recover the complete cost of the roof application through energy savings in an average of four and one-half years." According to George H. Sievert, former Executive Director of the Spray Polyurethane Foam Division (SPFD) of the Society of Plastics Industry, Inc.(SPI), "SPF has been a boon to metal buildings," he notes. "Install it on metal and it prevents expansion with the heat and contraction with the cold. That adds up to a controlled environment for the building structure. What's more, it helps stabilize the interior temperature of the building, which means fewer fossil fuels are consumed, and that lowers the emittance of CO2 into the atmosphere. No other type of roof is as environmentally oriented." Another benefit: At only three pounds per cubic foot (0.5 pounds per square foot), SPF weighs much less than conventional roofing alternatives, and in most retrofit applications, it weighs less than the loose aggregate remodel. Furthermore, many SPF applications have earned a UL 790 Class A fire resistance designation. The Importance Of A Protective Covering Despite its reputation as a highly advantageous roofing option, SPF does have a hurdle to overcome: UV rays. If left exposed to the sun, the polyurethane surface eventually breaks down, a process called degradation. Hence, the importance of a protective covering or coating. Eric Lundquist, Director of Marketing for the Flexible Products, Co., adds, "When an SPF roof is topped with a protective covering, such as a synthetic coating or an aggregate material, it becomes highly resistant to the elements." An SPF roofing system and subsequent coverings can be specified to resist many environmental factors, including chemicals, molds, mildew, fungus, hail and ice. Small areas of mechanical damage, including bird pecks, can be repaired with a compatible material, such as urethane, acrylic, or silicone (depending on coating type). This material can be applied with a caulking gun. SPF Earns A Strong Reputation A 1995 survey of more than 370 SPF roofing contractors reveals that 160 million square feet of SPF roofing are installed each year. SPF has been applied to warehouse roofs, unusually shaped, high-profile sports complexes, such as the 20-year-old Super Dome in New Orleans, high rises, manufacturing plants, condominiums, schools, and many other types of structures. SPF Gains The Attention Of The Military According to Rick Radobenko, President of Sprayfoam Southwest in Tempe, Arizona, the Navy and the Marines began using SPF back in the mid-1970s. "Once they saw how it performed and how versatile it was, they began specifying it a lot," he says. "They've used it on just about every type of building, from single-story mess halls and residences to huge equipment maintenance facilities and aircraft hangars." According to Radobenko, the military specifies roofing systems based on cost, functionality, resistance to harsh weather ranging from typhoon winds to desert heat, versatility, consistency, ease of installation, and long-term value. "When they discover something that works, they tend to use it again and again, " he says. Studies Conducted By The Navy In 1973, the Navy began conducting a series of studies to learn more about SPF roofing and what factors contributed to maximum performance and wear. Dr. Robert Alumbaugh, who worked as a civilian senior research chemist at what is now the Naval Facilities Engineering Service Center (formerly the Naval Civil Engineering Laboratory) at Port Hueneme in Southern California, lead this 15-year research program. Tests were conducted using small scale laboratory samples measuring 2 feet by 4 feet. Each sample had at least 1 1/2 inches of SPF material applied to a 1/2 inch plywood panel. The coverings on these samples included cementitious, silicones, acrylics, and urethanes. The samples were set out in varying environments, including marine atmospheric, desert, and high altitude conditions. In his research, Dr. Alumbuagh quickly discovered that some coatings worked better than others. "For example, in the early days of the single component urethane coatings, there were problems with a process called reversion," he recalls. "The polymer broke down and essentially turned to dust. This was more pronounced in the moist conditions along the sea coast than inland where the air is drier. It was a factor of the moisture, however, not the salt." In contrast, some of the silicone, urethane, and acrylic-coated SPF roofs installed on metal substrates at Port Heueneme are now 23 years old. Dr. Alumbaugh notes they were recoated only once and are still performing. Furthermore, a number of single component urethane and silicone coated SPF roofs installed by Navy crews at Subic Bay in the Philippines, which were supposed to be recoated every four years, are still in place. Dr. Alumbaugh adds, "The U.S. Navy no longer has the base at Subic Bay, but last I heard, they were only having to recoat those roofs every eight to ten years." Data And Specifications Are Compiled And Documented Dr. Alumbaugh eventually gathered enough data to set guidelines for a contractor and materials specifications manual that would help the Navy procure the best SPF materials and installation possible for any given climate or roof type. The specification was finalized by Keith H. Coultrap, CEO and Chairman of Sprayfoam Southwest. Coultrap also worked with Dr. Alumbaugh in preparing a guide entitled, Principles of Urethane Foam Roof Application. Another document, authored by Coultrap, Dr. Alumbuagh, and another associate, E.F. Humm, is entitled The User's Guide for Polyurethane Foam Roofing (HCEL Publication UG0011). Published in April 1987, this guide was commissioned by the Naval Civil Engineering Laboratory (NCEL) and has been utilized extensively by military personnel, roofing contractors, and architects all over the world. The Keys To Long-Term SPF Performance "In general, our studies and experiences showed us that, with quality materials and proper installation, an SPF roof will perform satisfactorily anywhere from 8 to 15 years before you have to recoat," says Dr. Alumbaugh. "Spray foam systems have been used all across the country," Dr. Alumbaugh adds. "A lot of Navy stations have them now. SPF is a good system that will perform and give you years of service when you do it right." A Roof Option With A History - And A Future Coultrap adds, "We've proved over a lot of years that we've got the capabilities to provide a 20 year roof, without question. Furthermore, Dr. Dean Kashiwagi at Arizona State University continues to do research on SPF roofs that furthers these claims." Coultrap concludes, "We've done thousands of these roofing projects over the years, and if the product wasn't any good and didn't do what it was supposed to do, we wouldn't be in business. Companies and organizations of all kinds, from the military to huge corporations like General Motors, are using it more and more. It's going to be around for the long haul." RM Close Window