Frost heave Frost heave is the upward movement of pavement caused when moisture in the ground freezes, expands, and lifts the concrete. The condition usually occurs during repeated freezing and thawing cycles.
Frost heave develops when frost forms beneath the pavement and pushes the supporting soil upward. Although some movement may reverse after thawing, repeated seasonal cycles can damage the sidewalk and weaken its foundation. Proper drainage and a stable pavement base help reduce the risk of frost-related movement.
Frequently Asked Questions About Frost heave
What is frost heave?
Upward movement of pavement caused when moisture in the ground freezes, expands and lifts the concrete, usually during repeated freeze-thaw cycles.
Why is it common in New York?
The region cycles above and below freezing many times each winter, so soil beneath sidewalks repeatedly freezes and thaws.
Does the sidewalk settle back after a thaw?
Sometimes partially, but repeated seasonal cycles progressively damage the slab and loosen its supporting base.
How is frost heave prevented?
Good drainage that keeps water out of the base, plus a well-compacted free-draining subbase, which reduces the water available to freeze.