Why does the NRCA recommend replacing composite roof decks made from laminated insulation and OSB?

The recommendation by the National Roofing Contractors Association (NRCA) to replace composite roof decks made from laminated insulation and oriented strand board (OSB) primarily stems from their tendency to hold moisture. When a roof deck retains moisture, it can lead to significant dimensional changes in the materials, which may compromise the integrity of the roof system. This moisture retention can foster mold growth, reduce insulation effectiveness, and potentially lead to structural issues over time.

In contrast, while the weight, cost, and load-bearing capacity of roof decks are important considerations, they aren't the primary reasons for replacement in this context. Moisture management is critical in roofing systems to ensure longevity, performance, and safety, which highlights why addressing this issue is paramount in the NRCA's guidelines.