Crack injection is a repair technique that fills a foundation crack with a specialized material, typically epoxy or polyurethane, injected under pressure directly into the crack to seal it from the inside out rather than simply covering the surface with a patch.
This method addresses the crack’s full depth, offering a more thorough seal than a surface-applied sealant that only covers the visible opening.
Choosing between the available injection materials depends significantly on whether the goal is structural repair, water sealing, or both, since epoxy and polyurethane serve somewhat different purposes.
What Does Crack Injection Involve?
- Cleaning and preparing the crack surface
- Installing injection ports along the crack’s length
- Injecting material under pressure to fill the full depth
- Sealing the surface once injection is complete
Why Is Crack Injection Important?
By filling the entire depth of a crack rather than just its visible surface, injection creates a more durable and reliable seal against water intrusion than a simple surface patch, which can eventually separate from the crack edges as the concrete continues to move slightly. This thoroughness makes injection the preferred method for cracks that are actively leaking or have a history of water intrusion.
Determining whether a crack is a good candidate for injection alone, versus requiring additional structural reinforcement, generally calls for a professional assessment, since injection seals a crack but doesn’t necessarily address an underlying structural cause if one is present. This upfront diagnosis ensures the repair actually addresses the crack’s true underlying cause rather than just its symptoms. This step protects the homeowner from paying for a repair that doesn’t actually solve the problem.
Crack Injection vs. Epoxy Injection
Crack injection is the general technique of filling a crack under pressure. Epoxy injection is one specific material choice within that technique, generally selected when structural bonding strength matters alongside the water-sealing function.