Green roof systems effectively manage stormwater, reduce urban heat, and support biodiversity, yet their adoption has been limited by the complexity of traditional, multi-layer assemblies. Foamed glass aggregate provides combined drainage and insulation in green roof assemblies, reducing structural loads while supporting healthy green roof ecosystems. Positioned beneath the growing medium, it provides free-draining capacity, thermal insulation, and load-bearing support, expanding the feasibility and landscape design potential of green roof systems. By combining drainage and insulation into a single lightweight layer, foamed glass aggregate simplifies green roof construction and reduces embodied carbon compared to traditional multi-layer assemblies.
90% lighter than stone drainage layers, reducing dead load.
Closed-cell structure prevents waterlogging and maintains healthy root systems.
R1.7 per inch adds to roof thermal performance and supports energy efficiency goals.
Consolidates drainage and insulation into a single layer, eliminating the need for multiple materials.
Delivered in 3CY supersacks that crane directly to roofs.
Made from 100% recycled glass with no VOCs, microplastics, or harmful additives.
A typical Passive House slab-on-grade assembly with foam glass gravel consists of the following layers from bottom to top:
This assembly eliminates the traditional layers of crushed stone for drainage and rigid foam boards for insulation, consolidating both functions into the foam glass gravel layer. The result is simpler construction, fewer materials to coordinate, and continuous thermal performance without interruption. For frost-protected shallow foundations, foam glass gravel can be used both beneath the slab and as insulated backfill around the perimeter, creating a continuous insulated envelope that protects against frost heaving while maintaining thermal performance.
Foamed glass aggregate is typically used as the drainage and insulation layer between the filter fabric and growing media. It replaces drainage mats and insulation boards, combining multiple layers into one single lightweight, free-draining system. Specific placement depends on the green roof system. Consult your green roof designer to see where foamed glass aggregate would best fit in your assembly.
Typical installations range from 6 – 12 inches depending on drainage requirements, insulation needs, and structural load constraints.
Yes. When compacted, foamed glass aggregate achieves compressive strength of up to 125 psi, supporting the weight of growing media, plants, and water. Its lightweight structure significantly reduces the total assembly weight of the green roof system.
Yes. Foamed glass aggregate integrates with most green roof assemblies and can be used with various waterproofing membranes and filter fabrics. We recommend coordinating with a green roof designer to confirm compatibility for your assembly.
No. Foamed glass aggregate is free-draining and does not absorb water, which prevents waterlogging in root systems. The foamed glass aggregate layer ensures excess water drains efficiently while the soil above provides moisture retention.
Yes. Foamed glass aggregate has a high friction angle that provides slope stability. Proper edge detailing and edge restraints are essential to prevent material migration.
Yes. Foamed glass aggregate is inert, non-toxic, and made from 100% recycled glass. It does not leach chemicals or microplastics that could harm plants or contaminate stormwater runoff.
