Repair Systems
Injection resins (epoxy rigid)
Rigid 2-part epoxy structural injection resin — technical reference for settlement cracks in Australian remedial building practice. Covers system selection, product comparisons, and brand equivalents.
What is injection resins (epoxy rigid)?
Epoxy rigid injection resins are structural adhesives injected under pressure into concrete cracks to restore full load transfer and tensile continuity across the fracture plane. The low-viscosity resin penetrates hairline cracks as narrow as 0.1 mm, bonding both crack faces as it cures to a high-strength rigid solid. Used by remedial engineers to repair structural cracks in beams, slabs, columns, and walls where continuity must be restored — typically specified as a precondition for the structure to return to its intended load use. The crack must be dry or only slightly damp for adequate bond development, and the multi-step injection process (port installation, chase sealing, low-pressure injection, grouting) requires experienced and licensed applicators with specialist equipment. Structural engineer sign-off is generally required after completion.
Product Reference
Scroll right to see all brands. Use each card's TDS link for verified specifications before specifying on any project.
Sika Injection-451 N / Sikadur-52
low-viscosity rigid 2-part epoxy injection, 380 mL
System Description
Structural reinstatement of dormant settlement cracks. Crack must be dry or pre-treat with PU first.
Technical Properties
- Restores structural continuity and full load transfer across the repaired crack
- Low viscosity variants penetrate hairline cracks down to 0.1–0.2 mm width
Limitations
- Rigid — crack may re-open or migrate if the original movement cause is not addressed
- Requires crack to be dry or only slightly damp — not effective in wet conditions
PROCUREMENT SOURCES
Fosroc Nitofill Epoxy
rigid 2-part epoxy injection resin, 380 mL cartridge
System Description
Structural reinstatement of dormant settlement cracks. Crack must be dry or pre-treat with PU first.
Technical Properties
- Restores structural continuity and full load transfer across the repaired crack
- Low viscosity variants penetrate hairline cracks down to 0.1–0.2 mm width
Limitations
- Rigid — crack may re-open or migrate if the original movement cause is not addressed
- Requires crack to be dry or only slightly damp — not effective in wet conditions
PROCUREMENT SOURCES
System Description
Structural reinstatement of dormant settlement cracks. Crack must be dry or pre-treat with PU first.
Technical Properties
- Restores structural continuity and full load transfer across the repaired crack
- Low viscosity variants penetrate hairline cracks down to 0.1–0.2 mm width
Limitations
- Rigid — crack may re-open or migrate if the original movement cause is not addressed
- Requires crack to be dry or only slightly damp — not effective in wet conditions
PROCUREMENT SOURCES
Brand Equivalents
Side-by-side view of equivalent products across all major brands.
| Material | Ardex | Sika | Fosroc | Tremco / Other | Parchem / Mapei |
|---|---|---|---|---|---|
| Epoxy injection resin (rigid) | — | Sika Injection-451 N / Sikadur-52 | Fosroc Nitofill Epoxy | — | Parchem Nitofill Epoxy |
Disclaimer
Information is general only. Product selection must be confirmed against project requirements, substrate condition, exposure class, manufacturer technical data sheets, NCC requirements, Australian Standards (including AS 3600), and consultant or structural engineer specifications. Do not rely on this reference as a substitute for professional engineering advice.
Concrete & Structural Defects
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Concrete & Structural Defects
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Settlement cracks
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