Which of these is appropriate during proper installation of expanded polystyrene (EPS) rigid board insulation to a nailable deck in a low slope roofing system?

The appropriate method during the installation of expanded polystyrene (EPS) rigid board insulation to a nailable deck in a low slope roofing system is to attach it by mechanically fastening to the deck. This method is important because mechanical fastening provides a secure and stable attachment, which is crucial in ensuring that the insulation remains in place throughout the roofing process and during the lifespan of the roof. It helps to prevent any movement or displacement that could occur due to environmental factors such as wind or thermal expansion, which are especially relevant in low slope systems where water drainage may be a concern.

Using mechanical fasteners creates a solid bond between the insulation and the deck, allowing for effective load distribution and maintaining the integrity of the roofing system. This ensures that the insulation performs its function effectively, contributing to the thermal performance and overall efficiency of the roofing system.

Other methods of attachment, like relying solely on adhesive or not providing any additional fastening, may not offer the necessary support and could lead to issues with insulation settling or becoming dislodged. Covering the insulation with a temporary cap might provide some protection, but it does not address the need for proper fastening required for long-term reliability. Thus, mechanical fastening is the best practice for securing EPS rigid board insulation in this context