Illinois Roofing Practice Exam

The NRCA advises against using composite roof decks made of laminated insulation and oriented strand board (OSB) primarily due to the issue of moisture retention. When these materials are exposed to moisture, they can absorb water, leading to dimensional changes, which compromises the integrity of the roofing system. This moisture can also create problems with fasteners becoming loose or ineffective, as the structural support of the deck may weaken over time.

Such moisture-related issues can result in increased maintenance costs and the potential for significant damage to the roofing system, making it critical to consider the long-term implications of using these materials. Proper design and material choices are essential in enhancing the durability and performance of roofing systems, which is why the NRCA emphasizes the drawbacks of composite roof decks in this context.