Lightweight. Low Carbon. Thermal Insulation.
High-performance buildings begin with thoughtful material selection, and subslab insulation plays a critical role in the long-term thermal and structural performance of a building envelope. Foam glass gravel is a solution that replaces both rigid foam insulation and crushed stone, delivering insulation, drainage, and load-bearing capacity in a single, streamlined layer.
Foam glass gravel simplifies the subslab assembly. Instead of layering multiple materials, it allows for a single approach that reduces thermal bridging, accelerates installation, and supports continuous insulation detailing under the entire slab. With an R-value of 1.7 per inch, foam glass gravel provides reliable below-grade insulation that contributes to energy efficiency and
Foam glass gravel performs under load with compressive strength of roughly 100psi, suitable for both slab-on-grade and load-distribution applications. Its closed-cell structure provides long-term moisture resistance while maintaining drainage properties, effectively acting as a capillary break and vapor-permeable insulation layer. This combination supports a durable, resilient substructure that helps protect slabs from moisture-related degradation over time.
Foam glass gravel is manufactured from 100% post-consumer recycled glass and carries a third-party verified Environmental Product Declaration (EPD) in accordance with ISO 21930:2017 and EN 15804. Learn more about Glavel’s commitment to material transparency here. With minimal embodied carbon and no synthetic binders or blowing agents, it supports project goals tied to LEED, Living Building Challenge, and other sustainable design frameworks.