What is foam glass gravel?

Foam glass gravel is a building material designed for a future where the built environment is not at odds with the natural environment. Both versatile and lightweight, foam glass gravel’s physical properties allow it to be a preferred material across the built environment. Not only is foam glass ultra lightweight (9.8 pounds per cubic foot), its closed-cell structure gives it thermal insulation of R1.7 per compacted inch. Foam glass can be used across a variety of construction verticals, from subslab insulation, to green roof fill, and infrastructure backfill.

Cellular Glass Close Up
PC: Oliver Parini
PC: Oliver Parini

How is foam glass gravel made?

The conversion of glass powder into foam glass begins with blending glass powder with a foaming agent. This mixture is fed across a continuous belt that carries the material through a tunnel furnace. The belt slowly carries powder through the furnace, heating the mixture to 1600°F. As the temperature increases, the glass softens, and gases generated by the foaming agent expand to create suspended bubbles. After foaming, the glass is slowly cooled to ambient temperature and the product solidifies to a slab 4x thicker than the original powder bed. Cracking occurs due to thermal stress induced by cooling, breaking the slab into smaller chunks, which eventually fall off the end of the belt into a concrete bunker for use.


Why build with foam glass gravel?

Foam glass gravel is an incredibly low embodied carbon product that can streamline jobsite complexities and reduce supply chain logistics on site. With easy installation, building with Glavel foam glass is a cost effective way to build a healthy building and increase envelope performance, while divesting from petroleum-derived materials. 

Glavel Close Up