Epoxy injection is a crack repair method that fills a foundation crack with epoxy resin, a rigid material that bonds strongly to concrete and effectively restores some of the structural integrity the crack originally compromised, in addition to sealing it against water.
Because epoxy cures rigid rather than flexible, it’s generally the preferred choice when a crack repair needs to address structural bonding, not just water infiltration.
This structural bonding capability distinguishes epoxy from more flexible injection alternatives designed primarily for water sealing rather than strength restoration.
What Does Epoxy Injection Involve?
- Surface cleaning and port installation along the crack
- Two-part epoxy resin mixed and injected under pressure
- Curing into a rigid, high-strength bond
- Surface finishing once the repair is complete
Why Is Epoxy Injection Important?
Because epoxy bonds so effectively to concrete and cures into a genuinely strong, rigid material, this repair method is often specified when a crack has some structural significance, essentially reuniting the two sides of the crack into something closer to their original strength. This makes epoxy the standard choice for cracks in structural elements where strength restoration matters as much as, or more than, water sealing.
Epoxy’s rigidity is also a limitation worth understanding, since a crack that continues to experience movement after repair, whether from ongoing settlement or seasonal expansion, can eventually crack again right alongside or through the rigid epoxy repair itself. A professional assessment beforehand helps determine whether epoxy alone is sufficient or additional reinforcement is warranted. This professional input is a small cost relative to the value of getting the repair right.
Epoxy Injection vs. Polyurethane Injection
Epoxy injection cures rigid, restoring structural strength but offering no flexibility for ongoing movement. Polyurethane injection cures flexible, better suited to actively leaking cracks or those still experiencing minor movement, though it doesn’t provide the same structural bonding epoxy does.