Issue link: http://www.e-digitaleditions.com/i/535074
18 STORM & SECURITY PROTECTION / FORECAST 2015 PROTECT / YOURSELF In the construction industry, building designs are engineered for structural integrity, which includes wind loads, stress loads, impact resistance, inflection toler- ance and attractive appearance to the end user. The products that go into a building have been tested and approved using the most up-to-date specifications. One of the least understood factors contributing to the safety of a building or its components is the affect of corrosion on a fastener or a fastening system. When a product is approved, the fasteners tested are brand new, right off the shelf. In the real world, how long will a fastener continue to have the same amount of strength as when it was installed, or how much of a safety factor needs to be applied to a new fastener to ensure that the product will not have a future failure? Currently, there are thousands of dollars being used to test for wind loads, design speeds and impact resis- tance, but who is testing product fasteners after they have been in the elements for a certain period of time? In the sterile environment of the preliminary testing lab with an unchanging environment free from the affects of mother nature, the protection or building charac- teristics would be unchanged and unchallenged, but in the real world products are always under attack from environmental elements. Anyone who has ever purchased an outdoor propane grill has seen the amazing speed at which the "perfect grill" becomes a "standard grill" to a grill that needs to be replaced. All the changes take place in a relatively short period of time. The same characteristics that affect an outdoor grill are being applied to building components, and the same sequence of breakdown is occurring. How completely will a shutter system installed 20 or 30 years ago really protect the occupants of a dwelling? Will the wind resistance of a pool cage built in the '90s really offer the same degree of effectiveness that it was designed to withstand when the fasteners that are holding the structure are being corroded by the chlorine or salt used to keep the pool water clean? The War on Corrosion Gary Hartshorn, of Hartshorn Construction, has said that he feels fastener failure might be the most significant issue affecting the pool cage industry. "Pool cages are being designed to resist higher wind speeds, but ultimately the ability of the fastener to retain the integrity of the structure reduces over time," he says. Additionally, Hartshorn is gathering evidence whether some of the new brick pavers being used in the pool industry are accelerating the corrosion of the fasteners directly attaching the pool cage to the pool deck. While everyone is in agreement that fasteners are evolving, no one is able to answer the question of how long a fastener will last. Greg Mann, All Points Screw, explains, "It is a very complex question with many variables including fertilizers, preservative-treated wood, de-icing salts, amount of moisture and salt air. Metal anchoring devices will corrode and lose load- carrying capacity when installed in corrosive environments or when installed in contact with corrosive materials. The intent of fastener manufacturers is to slow the corrosion process down." Mann adds, "The fastener industry is adapting with new products." Alco, Inc. has developed a two-component fastener to help improve the holding parameters of two dissim- ilar metals. The screw is made with bimetal technology: 300 (18-8) stainless steel head and shank fused and with hardened steel tapping threads and gimlet point. The benefits should be outstanding corrosion resistance, greater strength and better galvanic compatibility in dissimilar metal applications involving aluminum. Millennium Fasteners, along with other companies, is challenging the affects of corrosion by changing the composition of the screw, changing from a 410 to a 300 stainless composition and increasing the plating or coating of the screw along with ceramic top coating to eliminate moisture changes that expedite the corrosion of fasteners. The new coating and the introduction of new material should increase long-term metal fatigue | by Don Leggett | Should Fasteners Have an Expiration Date? If so, it could mean safer buildings and insurance credits. The insurance industry needs to develop a fastener inspection system that accounts for corrosion and includes a visual inspection.