Facade Cracking

Sika Injection-451 is a low-viscosity two-part epoxy injection resin designed for the structural reinstatement of dormant cracks in concrete and masonry. It penetrates hairline cracks under pressure, bonds the crack faces together and restores the structural continuity of the element. It is widely used in Australian remedial building practice for structural crack repair in concrete facade panels, columns, beams and masonry walls where the crack is dormant (not actively moving) and the substrate is dry or slightly damp. The system is applied by low-pressure injection using a series of injection ports installed at centres along the crack. The two-part resin is mixed at the injection nozzle during application. After cure, the repaired section achieves structural bond strength exceeding the tensile strength of the surrounding concrete. Sika Injection-451 is not suitable for active, water-bearing or wet cracks — use a hydrophilic PU injection resin for active or wet conditions. Always confirm crack type (dormant vs active) and crack width with a structural engineer before specifying epoxy injection on Class 2 strata facades.

Sika Injection-101 RC is a one-component hydrophilic polyurethane injection resin that reacts with water to expand and form a flexible, water-resistant foam or gel within the crack. It is used for sealing active, leaking or water-bearing cracks in concrete facade elements where water ingress through the crack is the primary concern, and where the crack is actively moving or wet. Because the resin is water-reactive, it is ideally suited to wet crack conditions where epoxy injection would be impractical. The cured material is flexible and can accommodate minor ongoing crack movement. It does not restore structural continuity of the cracked element — it seals against water ingress only. A separate structural assessment is required for active cracks in structural elements. Active and water-bearing facade cracks in Class 2 strata buildings must be assessed by a structural engineer before specifying any injection system. PU hydrophilic injection addresses the water ingress symptom but does not address the underlying cause of cracking.

Nitofill LVEP is Parchem's two-part low-viscosity epoxy injection resin for structural crack injection in concrete and masonry. It penetrates hairline dormant cracks under low-pressure injection and after cure restores structural bond across the crack interface. The product is part of the Parchem (formerly Fosroc) concrete repair range and is commonly specified for structural crack injection in concrete facade panels, columns, beams and masonry walls in Class 2 strata remediation. The system is applied through low-pressure injection ports installed at centres along the crack. Mixed at the injection nozzle during application, the two-part resin achieves high tensile bond strength after cure. Nitofill LVEP is broadly equivalent in function to Sika Injection-451 and is specified where the Parchem supply chain is preferred or required by specification. Crack dormancy must be confirmed before specifying epoxy injection — active cracks require PU hydrophilic injection or movement joint treatment. Confirm current product designation and technical data with Parchem before specifying.

Acratex Surfacekote is a high-build elastomeric acrylic coating system from the Acratex (Dulux Group) range, used for crack-bridging over hairline and fine facade cracks in concrete and masonry exterior wall surfaces. It is applied by roller or airless spray in multiple coats to build a flexible film over the facade surface that bridges fine cracks and provides a water-resistant exterior coating layer. Acratex Surfacekote is used after structural crack injection has been completed (where injection is required) to provide a continuous, crack-bridging exterior coating finish over the repaired surface. For fine hairline facade cracks that do not require structural injection, it may be applied as the primary crack treatment. It is not a substitute for structural crack injection on dormant or active structural cracks. The product is part of the broader Acratex exterior coating system. Confirm surface preparation, primer selection and number of coats required with the current Acratex technical data sheet and system specification. The facade surface must be clean, sound and free of contamination before application.

Sikaflex-11 FC+ is a one-component moisture-curing polyurethane sealant widely used at sawcut and formed control joints and movement joints in concrete and masonry facade elements. At the facade level, it is applied to formed or sawcut control joints between precast or insitu concrete panels, at junctions between different facade materials, and to movement joints at floor-to-facade junctions and slab edges. Facade cracks that result from the absence or failure of movement joints — including cracks at regular spacing in concrete panel systems — may be addressed by forming a sawcut control joint at the crack location and sealing with Sikaflex-11 FC+. This converts a random crack into a controlled, sealed movement joint. The approach requires structural engineer review to confirm that forming a control joint at that location is appropriate. Applied by gun from standard cartridge over backer rod or bond breaker tape. Available in multiple standard colours. Confirm primer requirements on concrete and masonry substrates with Sika TDS before application.