Which material should not be used for fastening foamglas?

In the context of fastening Foamglas, wire should not be used due to the risk of compromising the material's inherent properties and insulation performance. Foamglas is a closed-cell cellular glass insulation, and using wire can puncture or deform the structure of the material, leading to potential thermal bridging. The integrity of Foamglas is crucial to maintaining its insulative qualities, and fasteners should not compromise the air-sealed environment that the cellular structure provides.

In contrast, staples, clips, and adhesive can be specifically chosen to secure Foamglas without damaging it, allowing for proper installation while minimizing the risk of air infiltration or moisture accumulation. Therefore, the focus on avoiding wire as a fastening material ensures that the performance of Foamglas insulation remains optimal.