The subject invention relates to low-slope roofs that are typically found on commercial and industrial buildings and in particular, to prefabricated multi-layer roofing panels and a roofing system for low-slope roofs.
Commercial and industrial buildings typically have roofs with low-slope roof decks. The roofing systems for roofs with low-slope roof decks typically include one or more layers of low-density insulation, such as low-density polymer-based foam insulation layer, that, if not protected, can be partially crushed or otherwise damaged from worker traffic over the insulation, the placement of heaving objects on the insulation, the weather, and other causes commonly encountered in roofing construction; a layer of roofing cover boards that overlie and protect the more fragile low-density insulation from damage, act as fire barriers, and augment the insulating function of the low-density insulation; and an uppermost layer that is a waterproofing membrane. Normally, these three components (the low-density insulation, the roofing cover boards, and the waterproofing membrane) of the roofing system are separately manufactured and separately and successively applied to the low-slope roof deck. These roofing systems function very well and there are multi-layer roofing panels such as the roofing panels disclosed in U.S. Pat. Nos. 3,111,787; 3,468,086; 4,680,909; 4,706,435; 4,965,977; and 5,251,416 for use in roofing systems. However, there has remained a need for an improved prefabricated multi-layer roofing panel: that combines the insulation layer, the roofing cover board layer, and the waterproofing membrane layer into a single unit; that can be effectively, easily, and quickly self-adhered to a roof substrate; that has a waterproofing membrane which can be effectively, easily and quickly joined to the membranes of other roofing panels to form a waterproofing membrane for the roofing system; and/or that includes an interlocking structure for effectively, easily, and quickly locking together the roofing panels of the roofing system. With the use of such an improved prefabricated multi-layer roofing panel, roofing systems for low-slope roof decks can be improved and/or the time, labor and costs associated with the installation of roofing systems on low-slope roof decks can be reduced. In addition, the assembly of the prefabricated multi-layer roofing panels under controlled factory conditions greatly reduces the possibility of defects in the roofing system.