Structural soil A highly engineered stone-and-soil mixture designed to support the heavy weight of concrete pavements while remaining porous enough for tree root growth.
Standard soil must be heavily compacted to support a concrete sidewalk without settling, but highly compacted soil suffocates tree roots and forces them to grow upward, cracking the pavement. Structural soil, such as CU-Structural Soil, features a rigid skeleton of crushed stone that transfers pavement loads while leaving open voids filled with nutrient-rich soil. Utilizing this material beneath new NYC sidewalks allows tree roots to grow downward, preventing future sidewalk buckling.
Frequently Asked Questions About Structural soil
What is structural soil?
An engineered mix of crushed stone and soil that supports pavement loads while remaining porous enough for tree roots to grow through.
What problem does it solve?
Ordinary soil must be heavily compacted to carry a sidewalk, but compacted soil suffocates roots and drives them upward into the slab.
How does it work?
A rigid stone skeleton carries the load while the voids between stones hold soil, giving roots space to grow downward instead of under the concrete.
When is it worth using?
On new sidewalk construction near trees, where preventing future root heaving is worth the added material cost.