Concrete Crack Repair and Injection

Epoxy cures as a rigid adhesive and is used to bond selected dormant cracks where structural continuity is required. Polyurethane reacts or cures into a flexible solid or foam and is used mainly to stop water and accommodate limited movement. Harrowgate chooses from crack behaviour, moisture, access, and the engineer's intended repair function.

Flowing water interferes with many structural epoxies and can carry material away. We first control or redirect the water, often with a compatible water-reactive polyurethane, then clean and assess the crack. Structural epoxy is used only when the substrate and moisture satisfy its requirements and the engineer confirms that rigid bonding is appropriate.

We compare crack width and displacement over time using gauges, tell-tales, survey points, temperature records, and load or leakage observations. Pattern and location also matter. Movement related to settlement, joints, or structural load must be resolved before rigid repair. A one-time width reading does not establish that a crack is dormant.

Proper port spacing, surface sealing, resin viscosity, pressure, and sequence are designed to fill the internal crack plane. Material reaching adjacent ports or the opposite face provides evidence of communication. Where required, cores or other verification are completed. Face sealing alone is not injection and cannot demonstrate internal bond or water cutoff.

No. Hairline surface checking, moving joints, wide broken sections, corrosion delamination, contaminated cracks, settlement cracks, and voided concrete may need routing, replacement, flexible joint work, reinforcement, or stabilization. Harrowgate investigates the mechanism and rejects injection where the material cannot reach sound crack walls or the structure will continue moving.

Polyurethane can form an effective flexible cutoff within a crack, but water can bypass through adjacent cracks, wall-floor joints, tie holes, penetrations, or failed exterior drainage. Harrowgate traces the route and treats connected defects. Where sustained hydrostatic pressure remains, exterior membrane, footing drain, sump, or grading correction may be part of the complete scope.

After the resin has cured, surface ports and temporary seal are removed where the finish requires it. Holes and shallow recesses are filled with compatible repair material, then the surface is ground or prepared for membrane, coating, or architectural finish. Exposed structural repairs may remain visible when inspection access is more important than appearance.