How should rigid board insulation be applied to non-nailable decks?

Applying rigid board insulation to non-nailable decks requires a method that ensures a secure bond to the surface while accommodating the characteristics of the deck. Using adhesive applied to a base sheet is the appropriate choice because it creates a solid and continuous layer of insulation. This method ensures that the insulation is effectively bonded without the need for nailing, which is not possible on non-nailable decks.

Adhesives can distribute stresses and movements in roofing systems more evenly, minimizing the risk of damage or failure. This technique also helps maintain the integrity of the insulation and creates a more energy-efficient building envelope by reducing air leaks.

In contrast, the alternatives, such as mechanical fasteners, heavy-duty tape, or setting the insulation in sand, might not provide the same level of security and resistance to environmental factors, leading to potential issues in insulation performance and longevity.