Crack injection A specialized repair technique where liquid epoxy or polyurethane resin is forced into concrete cracks to seal them against moisture penetration.
In civil and foundation engineering, crack injection is highly effective at sealing structural concrete elements. However, for standard NYC sidewalks, injection is rarely used because a cracked sidewalk flag usually indicates subgrade settling or root growth. To permanently resolve a cracked sidewalk violation, the DOT requires the physical replacement of the affected concrete flags.
Frequently Asked Questions About Crack injection
What is crack injection?
A repair technique forcing epoxy or polyurethane resin into concrete cracks to seal them against moisture.
Is it used on NYC sidewalks?
Rarely. A cracked sidewalk flag usually reflects subgrade settlement or root growth, so sealing the crack does not address the cause.
Where is injection effective?
On structural concrete elements such as foundation walls, where the crack is the problem rather than a symptom.
Will injection clear a sidewalk violation?
No. DOT requires replacement of the affected flags.