Stephen Childs, Technical Services Manager, OMG Roofing Products
Commercial, industrial and institutional buildings can be constructed with several different roof deck types, including steel, wood, concrete, gypsum and others. Each has a unique set of characteristics that require different mechanical fasteners to meet the various needs of the roof assembly. Regardless of the specific deck type, contractors should always ensure that the fasteners used to secure any roofing components are proven for the application and are code compliant (e.g., Factory Mutual, Miami-Dade County).
Since first used to attach insulation in the early 1980s, roofing fasteners have evolved a great deal. Prior to 1980, fasteners had not been specifically designed or engineered for commercial roofing applications. Fastener pullout, back out and corrosion resistance requirements were unknown and, as a result, fastener performance was not always up to the task. As fastener manufacturers started working closely with roof system manufacturers, more sophisticated and task-specific roofing fasteners were developed.
At first, wood and steel were the only roof decks suitable for mechanical fastening. Cementitious wood fiber (Tectum), gypsum, lightweight insulating concrete and even structural concrete decks possessed unique properties that did not allow insulation or membrane to be secured with traditional screws. Fastener manufacturers began to recognize the roofing world as a new opportunity and dedicated resources to design and engineer products to address market demands. New fastener companies solely dedicated to the roofing industry emerged, bringing with them new fastener designs and better performance. Below is a general description of the most common decks and fastener options.