ABSTRACT
Adhesion/cohesion strength is amongst the main considerations in the design of any roofing system. Traditionally, only static wind-uplift tests were conducted on the mock-up assembly. Testing is required for each design for both fatigue and ultimate static resistance. Baskaran and Dutt showed results of such tests for particular design, where the fatigue resistance is expressed as a percentage of the static resistance. Resistance to abrasion from traffic and wind-borne particulate needs also to be considered during the roof design. While the water vapor permeance of Spray Polyurethane Foam (SPF) is an important property, it has only a minor significance in the assessment of moisture performance of the whole SPF roof. Kashiwagi and Moor recognized that moisture performance is one of the critical factors in the SPF roof design. Moisture accumulation in the roof depends on its design, indoor and outdoor conditions, permeance of elastomeric coating, permeability of internal finishes, and penetrations in the roof membranes.
