ORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO   ONTARIO ROOFING NEWS – FALL 2018  13 system failure. IE of the cover board and fastener plate will establish their interaction and determine the resistance required. In addition, several parameter evaluations can be performed economically through IE, such as variations in plate design and dimensions, to identify the optimum design combination of cover boards and fastener plates. Resistance to Repetitive Loading An example of rooftop repetitive loading is the vibrations of a photovoltaic panel and/or ballast tray, which in current practice are installed directly on a roof surface. Photo 3 shows the damage that can occur to insulation from repetitive loading when no protection is provided. When ballast weight is small (for example, 10 pounds), the resulting damage includes the compression and indentation on the insulation surface below the membrane. For heavier ballast or severe vibrations, the insulation facer can be punctured in addition to the compression of the insulation, which is not captured in material compressive strength evaluation. IE will help determine the required strength of the cover board to fulfill its protective function. Currently, there are no standard test methods to capture this behaviour. Dynamic Puncture Resistance Evaluating dynamic puncture resistance is essential to simulate a sudden impact, such as the dropping of a hammer or other tool during a roof system repair or damage from a severe hail event. Current dynamic impact testing is for individual materials, such as membranes. However, the puncture of a membrane can be minimized by the substrate below. Cover boards absorb the impact energy and protect the membrane and insulation. Therefore, for the interaction of the membrane and insulation with the cover board under dynamic impact, IE is needed to establish the resistance required. Photo 4 shows the damage to the membrane and insulation that was observed in the aftermath of a hail event for a system without a cover board. A thumb-sized depression was produced on the membrane, and a depression of more than 2 inches in diameter was observed on the top of the insulation board. Photo 4 depicts schematically the benefit a cover board provides in protecting adjacent substrates. The Benefits of IE To ensure cover boards are protecting a roof assembly, they must be evaluated with the materials they are intended to protect. This concept gave rise to the formulation of interface testing, defined as the intermediate testing between material and system testing that includes two or more dissimilar materials. As rooftops transition from having simple minimal burdens and foot traffic to increased foot traffic, overburdens and extreme climatic events, the cover boards of the future have a bigger role to fulfill. They will require more extensive and focused evaluation, and IE will be required to ensure cover boards fulfill the dual function of minimizing the deterioration of other materials and providing resiliency to roof assemblies. This article has been reprinted with permission from Professional Roofing. Bas Baskaran is a group leader at the National Research Council of Canada in Ottawa, and Dominique Lefebvre is a research officer at the National Research Council of Canada. www.sparmarathon.ca Roofing & Sheet Metal Super Service Centres OAKVILLE, ON (905) 825-0034 WESTON, ON (Weston Road) (416) 745-4111 BARRIE, ON (705) 792-6683 EDMONTON, AB (780) 432-2786 HAMILTON, ON (905) 560-2858 PICKERING, ON (905) 426-4443 WESTON, ON (Signet Drive) (416) 744-2050 CALGARY, AB (403) 255-8236 TORONTO, ON (416) 534-8421 LONDON, ON (519) 668-3626 WINNIPEG, MB (204) 338-7613 Protective Roofing Safety Products BY The PR 100 Guardrail Systemis an efficient and practical perimeter guardrail that allows you to work right to the edge of the roof. • Meets and exceeds OSHA & WCB requirements • Accommodates: parapets and cant strips • Provides unobstructed access to roof edge • Easy to install The PR 600 Mobile Fall Protection System can be moved along the roof by pulling the cart to the desired working location, providing a safe working area. The PR 600 meets O.S.H.A. compliance 1926.502D. www.sparmarathon.ca Roofing & Sheet Metal Super Service Centres OAKVILLE, ON (905) 825-0034 WESTON, ON (Weston Road) (416) 745-4111 BARRIE, ON (705) 792-6683 EDMONTON, AB (780) 432-2786 HAMILTON, ON (905) 560-2858 PICKERING, ON (905) 426-4443 WESTON, ON (Signet Drive) (416) 744-2050 CALGARY, AB (403) 255-8236 TORONTO, ON (416) 534-8421 LONDON, ON (519) 668-3626 WINNIPEG, MB (204) 338-7613 Protective Roofing Safety Products BY The PR 100 Guardrail Systemis an efficient and practical perimeter guardrail that allows you to work right to the edge of the roof. • Meets and exceeds OSHA & WCB requirements • Accommodates: parapets and cant strips • Provides unobstructed access to roof edge • Easy to install The PR 600 Mobile Fall Protection System can be moved along the roof by pulling the cart to the desired working location, providing a safe working area. The PR 600 meets O.S.H.A. compliance 1926.502D. www.sparmarathon.ca Roofing & Sheet Metal Super Service Centres OAKVILLE, ON (905) 825-0034 WESTON, ON (Weston Road) (416) 745-4111 BARRIE, ON (705) 792-6683 EDMONTON, AB (780) 432-2786 HAMILTON, ON (905) 560-2858 PICKERING, ON (905) 426-4443 WESTON, ON (Signet Drive) (416) 744-2050 CALGARY, AB (403) 255-8236 TORONTO, ON (416) 534-8421 LONDON, ON (519) 668-3626 WINNIPEG, MB (204) 338-7613 Protective Roofing Safety Products BY The PR 100 Guardrail Systemis an efficient and practical perimeter guardrail that allows you to work right to the edge of the roof. • Meets and exceeds OSHA & WCB requirements • Accommodates: parapets and cant strips • Provides unobstructed access to roof edge • Easy to install The PR 600 Mobile Fall Protection System can be moved along the roof by pulling the cart to the desired working location, providing a safe working area. The PR 600 meets O.S.H.A. compliance 1926.502D.