Waterproofing

Waterproofing is a product or coating that prevent the passage of water or vapour from passing or migrate through building materials or elements. It is important to prevent water and vapour ingress from entering building elements and causing water damage.

Left unprotected, water can cause damp, mould, damaged finishes and corrosion of reinforcement, leading to costly repairs. Cement waterproofing is one option within the wider range of technologies, and floor waterproofing is a key part of protecting wet areas. Sika Australia provides waterproofing mortars, flexible and liquid-applied membranes, injection grouts, coatings and joint sealants, selected to suit the project requirements. 

There is no single waterproofing membrane that is best for every roof. The appropriate system depends on the roof design, service conditions and project requirements. Sika Australia provides several waterproofing technologies, including flexible membrane systems, liquid-applied membranes, coatings and sheet membrane systems.

For concrete roof waterproofing membrane applications, the substrate and required waterproofing performance should guide system selection. A flat roof waterproofing membrane also needs to suit the roof's drainage requirements, while a self adhesive waterproof membrane sheeting system may be considered where a sheet membrane technology is appropriate. Sika Australia recommends selecting the membrane system to suit the specific service criteria and project details. 

The required curing time before applying waterproofing to a waterproofing concrete slab depends on the specific membrane system and substrate conditions. For a foundation waterproofing membrane, the substrate must be sufficiently dry and prepared according to the product data sheet. Substrate preparation is critical to achieving a successful bond, and membrane application must achieve the recommended dry film thickness.

Different Sika Australia waterproofing products have varying moisture tolerances. As a general guideline, allow the concrete to cure and dry sufficiently before applying waterproofing. Ideally, the concrete’s relative humidity should be below 75% before application. If the reading is higher, application may still be possible with certain systems, provided the moisture conditions are assessed. 

Yes, waterproofing products can be used as part of the repair of roofs, provided the selected system is suitable for the roof substrate, service conditions and the specific source of water ingress. Sika Australia offers several waterproofing technologies, including flexible membrane systems, liquid-applied membranes, coatings and spray-applied membranes.

For leaking structures, Sika Australia also provides injection systems designed for waterproofing buildings and underground structures. Sprayable waterproofing is one available technology, but the appropriate system should be selected according to the project requirements. Proper substrate preparation and membrane application, including the recommended dry film thickness, are important considerations for successful waterproofing. 

Best practice for waterproofing a shower or wet area begins with selecting a suitable waterproofing membrane. Ensure substrates are fixed according to the manufacturer and designed to receive tiles. Prime surfaces with a suitable primer compatible with the substrate and selected membrane. Apply a minimum of two coats of the selected waterproofing membrane, allowing drying between coats. Inspect each coating after application for defects.

Allow drying in accordance with the PDS before subsequent coverings. Waterproofing mortars can be used beneath tiling systems to help prevent water infiltration. Ensure compliant falls manage surface and subsurface water, and use a shower water sealer where specific wet-area requirements and standards apply. 

Yes, Sika Australia waterproofing systems can protect commercial building applications from water ingress. The range covers basements, underground structures, bathrooms, kitchens, balconies and water-retaining structures, with flexible membranes, liquid-applied membranes, waterproofing mortars, injection grouts and coatings.

For a hospital flooring, select the waterproofing system for the specific service criteria, exposure and building project details. Hospital flooring often uses vinyl, so the membrane should be coated with a suitable skim coat before vinyl flooring fixing.  

Sealants used alongside a waterproofing membrane depend on the joints, interfaces and substrate details within the system. Sika Australia includes joint sealants as part of its broader waterproofing technologies, alongside flexible and liquid-applied membranes, waterproofing mortars and coatings.

Products such as sika self leveling sealant or an external door sealant may be relevant to specific joint or perimeter applications, but their suitability depends on the substrate and membrane system. Tooling caulking and a plastic adhesion promoter should only be specified where the relevant product documentation supports their use. Compatibility with the complete waterproofing system must be confirmed before application. 

Polyurethane water proofing and cementitious coatings are different waterproofing technologies, and the appropriate choice depends on the substrate, service conditions and project requirements. Sika Australia offers flexible membrane systems, liquid-applied membranes, waterproofing mortars and coatings for different applications.

An elastic polyurethane coating typically provides flexibility and crack-bridging properties, while cementitious coatings are rigid and suitable for different substrate conditions. A pu floor sealer may form part of a floor waterproofing system. Product-specific technical documentation should confirm suitability, as performance differences depend on the formulation rather than the general category alone. 

Construction joint waterproofing typically uses a suitable joint treatment system designed to contain water and prevent water ingress through the joint. Sika Australia identifies the installation of a waterstop angle as an important consideration for containing water in wet areas and lists construction and movement joints among its waterproofing system applications.

The appropriate solution depends on the joint design, substrate and service conditions. Sika Australia’s waterproofing technologies include joint sealants, waterproofing mortars, flexible and liquid-applied membranes, injection grouts and coatings. A sika waterproofing compound should only be selected where its product documentation confirms suitability for the specific construction joint application. 

The lifespan of waterproofing depends on the system, service conditions, substrate and quality of installation. Best practice focuses on selecting a membrane system that suits the service criteria, with proper substrate preparation and application of the recommended dry film thickness.

The time takes for waterproofing to remain effective can therefore vary between projects. Appropriate system selection, correct installation and attention to project-specific details are important for achieving long-lasting, watertight structures. Sika Australia does not provide a single service-life timeframe, as performance depends on exposure conditions and maintenance.