THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN 10  ONTARIO ROOFING NEWS – FALL 2018 Cover Boards in Commercial Roofing T he North American roofing community has long recognized the benefits of including a cover board to increase a roof assembly’s durability. In the past, the main purpose of cover boards was to protect against weather elements and minimal foot traffic. As a result, cover boards were evaluated for their material properties based on standards that were developed for individual board types. Rooftops now are used as platforms for add-ons, such as photovoltaic or vegetative roof systems, which result in increased foot traffic, loads and stresses on roof systems. In addition to the increased physical burdens, there are more frequent extreme weather events, including hail storms and heavy winds, that can result in debris and other items contacting roof systems. The roofing industry has responded to this need by manufacturing a wide variety of boards made from asphalt, gypsum, cement, wood fiber, insulation and recycled products. These boards are placed above the insulation substrate to provide additional protection for roof systems. However, there continues to be damage observed to substrates. This leads to the fundamental questions: What is a cover board? What should a cover board be contributing to a roof assembly? What They Do A cover board is a rigid roof material in a compact roof assembly that enhances resiliency and durability. It is installed below the membrane and above the insulation to minimize the deterioration of other materials during the service life of the roof. To achieve the goal of providing protection and minimizing deterioration, cover boards must meet certain criteria of evaluation. There are several levels of evaluation that can be considered for cover boards, including material, system and interface. The following chart summarizes the three evaluation levels and resulting outcomes and benefits. Material evaluation is useful to obtain the properties of an individual material and can be used to compare the performance of different products. Properties, such as flexural strength and water absorption, can be assessed at the individual material level. However, in roofing, the materials, including the cover board, are integrated with one another, which results in interactions. Material testing alone does not capture the interactive element. AssessingCoverBoards Anewevaluationtechniqueisneeded todeterminecoverboards’protectivefunction By Dominique Lefebvre and Bas Baskaran