ORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO   ONTARIO ROOFING NEWS – FALL 2018  11 System evaluations, which are performed under specific set laboratory conditions, assess the overall assembly response and are essential to demonstrating code compliance. However, a system test will not isolate a cover board’s protective characteristics. A system test focuses on the weakest link concept and failure mode and may not directly provide information about cover board performance. Furthermore, system evaluations can be tedious, costly and time-consuming because of the large number of variables that can be tested. MATERIAL SYSTEM INTERFACE FOCUS Individual material  Mimic field construction  Interaction of specific dissimilar materials OUTCOME Performance of individual material Overall assembly response under specific exposure conditions  Performance of two or more materials integrated with one another BENEFIT  To compare the relative performance of different materials  Code compliance for performance requirements To minimize system testing  To assess selected interface compatibility parameters Levels of Evaluation for Roofing Products Photo 1: Membrane peel from cover board caused by shear. Photo 2: Cover board pull-through caused by wind uplift.