Frequently asked questions
Injection waterproofing systems seal water-bearing cracks, joints or construction interfaces by introducing a suitable resin or grout into the affected area. During concrete injection, the material travels through cracks or designated injection points and forms a barrier that helps prevent further water ingress.
Sika Australia offers several systems for different requirements, including Sika® Injection-306, Sika® Injection-111 and Sika® Injection-222. Hydrophilic products such as SikaFuko® systems and SikaSwell® profiles use water-reactive technology for sealing construction joints. The appropriate system depends on the joint, leak condition and required waterproofing approach.
The suitable system for concrete crack injection depends on the crack and the required waterproofing approach. Sika Australia provides polyurethane injection options including Sika® Injection-111, a hydrophobic semi-flexible polyurethane injection grout, and Sika® Injection-222, a hydrophilic flexible polyurethane grout.
For permanent watertight sealing, Sika® Injection-306 is a polyacrylic elastic injection resin suitable for crack and joint injection and sealing water-bearing cracks. Crack injection should be selected according to the specific water ingress and concrete conditions. Sika Australia offers a range of injection systems, and the appropriate choice depends on whether the priority is waterproofing or structural repair. Epoxy injection is also available for rigid structural bonding applications.
Polyurethane injection involves introducing a suitable polyurethane grout into a concrete crack through an injection system to address water leakage. For polyurethane resin injection, Sika Australia provides Sika® Injection-111, a hydrophobic semi-flexible polyurethane injection grout that reacts with water to create a hydrophobic foam and stop active water flow.
Sika® Injection-222 is a hydrophilic flexible polyurethane grout that reacts with water to form a permanently flexible seal. A leak injection system should be selected and installed according to the relevant Sika Australia technical information. Injection pressure, equipment and port spacing are specified in the product data sheets and should be followed for successful sealing. Sika Australia provides detailed application guidance for its injection systems.
Yes, injection waterproofing can be used for basement and below-ground concrete structures where water ingress needs to be addressed. Sika Australia provides injection products and systems for sealing construction joints and water-bearing areas, including Sika® Injection-306, Sika® Injection-111 and Sika® Injection-222.
These systems can form part of a basement waterproofing strategy, particularly where injection is appropriate for the specific leak or joint condition. The supplied Sika Australia information does not specify a basement waterproofing membrane, negative side waterproofing method or detailed foundation injection procedure, so these applications should be selected according to the relevant project requirements and Sika Australia technical documentation.
Yes. Hydrophilic waterstops are suitable for sealing construction joints in concrete structures, particularly non-movement joints. SikaSwell® A profiles and SikaSwell® S-2 hydrophilic sealant swell when they come into contact with water, helping seal construction joints and concrete penetrations.
For a waterstop for concrete walls, the appropriate system depends on the joint and project requirements. SikaSwell® P Profiles are also designed for construction joints, including precast concrete applications. These products form part of Sika Australia's range of construction joint waterstop solutions for watertight concrete systems.
Polyurethane injection can be effective for sealing leaking concrete cracks exposed to hydrostatic pressure, provided the appropriate polyurethane system is selected for the conditions. Sika® Injection-111 is a hydrophobic polyurethane grout designed to stop active water flow and water ingress, including leaks in concrete cracks and joints.
Sika® Injection-222 is a hydrophilic polyurethane grout that reacts with water to form a permanently flexible seal and is suitable for hydrostatic pressure environments. Polyurethane crack injection should be selected according to the crack condition and required performance, with structural crack repair assessed separately where load transfer is required.
Before crack injection, the concrete should be assessed to confirm that the crack and surrounding substrate are suitable for the selected injection system. For concrete crack repair, the substrate condition, crack characteristics and presence of water influence the injection approach and material selection.
Sika Australia’s crack injection guidance recommends drilling and installing mechanical packers capable of withstanding the required injection pressure, with slow, low-pressure injection generally preferred to rapid, high-pressure injection. For concrete injection repair, the appropriate equipment and resin also depend on whether the objective is waterproofing or load transfer.
Yes, crack injection systems can be used for foundation crack injection and some retaining wall cracks, mainly where controlling water ingress is the goal. Sika Australia provides polyurethane and polyacrylic injection resins for sealing cracks and joints, including Sika® Injection-306 for water-bearing cracks.
For concrete foundation crack repair or concrete wall crack repair, assess the crack first: flexible polyurethane systems are typically used for waterproofing, while concrete crack injection epoxy provides rigid structural bonding. If cracks are structural or still moving, have an engineer assess the cause before repair.
Water can continue leaking after an initial repair if the selected injection system does not match the crack and water conditions, or if the crack has not been completely sealed. Sika Australia notes that long-term watertightness depends on selecting the appropriate injection material for the specific leak.
For example, leaking cracks under hydrostatic pressure may require a staged injection approach using a temporary waterstopping material followed by a flexible resin for permanent sealing. Basement leak repair, concrete slab crack repair and epoxy injection crack repair therefore require assessment of the crack, moisture conditions and repair objective before treatment.
Epoxy and polyurethane injection are used for different crack repair requirements. Epoxy injection generally provides rigid bonding and is used where structural bonding or force transfer across a suitable crack is required. Polyurethane injection is more commonly selected for waterproofing leaking cracks, as certain Sika Australia polyurethane injection materials are flexible and can react with water to form a seal.
The choice depends on whether the priority is structural crack repair or stopping water ingress, along with crack condition, movement and hydrostatic pressure. For leaking cracks, pu injection and urethane injection systems can provide suitable flexible, water-reactive sealing when specified correctly.