Insulation materials used in below ground structure must perform reliably for the entire life of the building – typically 50 to 60 years or more* – as they cannot be replaced once construction is complete. 

The challenge being that below-ground insulation faces relentless pressure: moisture exposure, thermal fluctuations, and crucially avoid deformation under continuous load. If it absorbs water, loses thermal efficiency, or deforms under weight, the consequences can be severe—uneven support, cracks, force redistribution, and costly structural repairs.

That’s why durability means more than lifespan. It’s about consistent mechanical strength and thermal performance, with materials that remain stable, resilient, and free from harmful substances throughout the building’s life.

Discover how FOAMGLAS® cellular glass insulation helps you overcome these challenges in our Below Ground White Paper.