For high-demand structures like basement walls, lift pits, retaining walls, and swimming pools, Gripset C-1P provides a single-component, fibre-reinforced cementitious barrier that resists water penetration from both the positive and negative sides. Formulated with graded aggregates and polymers, it bridges cracks on concrete, masonry, and aerated concrete block substrates while withstanding continuous immersion, UV exposure, and ground moisture.
Gripset C-1P cures to form a flexible, non-toxic waterproof barrier. It bonds directly to concrete, render, masonry, compressed fibre cement sheeting, plasterboard, and aerated concrete panels. Because it withstands both positive pressure (up to 5 bar) and negative pressure (up to 1.5 bar), it prevents water ingress in deep underground spaces like lift pits and earth shelters where external access is impossible. It is approved to AS 4020 for potable water storage, making it suitable for internal tank linings. The polymer-modified chemistry allows application over damp and green concrete without compromising adhesion, and it is fully compatible with polymer-modified tile adhesives and screeds.
Gripset C-1P is suitable for commercial, industrial, and residential applications on the following substrates and structures:
Substrates must be clean, sound, and free of laitance, curing compounds, and contaminants. Grind or abrade structurally unsound layers. Concrete must cure for 28 days and cement render for 7 days before application. Non-porous or burnished concrete surfaces must be mechanically abraded, cleaned, and pre-dampened, or primed with Gripset OP Primer at 1 litre per 10m². Porous mineral substrates must be pre-wetted with a light water mist, leaving no standing or ponding water.
Mix only with an electric stirrer and paddle; do not mix by hand. Always add the dry powder to the water to prevent clumping. Allow the mix to settle for 2 to 3 minutes, then re-stir lightly before application. Apply coats in alternating directions using a wet film gauge to monitor coverage.
All joints, junctions, penetrations, and cracks must be detailed prior to applying the overall membrane:
Yes, Gripset C-1P is approved for potable water storage facilities to AS 40200. This ensures it is safe for contact with drinking water when fully cured and installed correctly.
It handles up to 5 bar of positive hydrostatic pressure and 1.5 bar of negative pressure without visual penetration. This makes it suitable for demanding below-ground and immersed applications like basements or lift pits.
Yes, you can apply Gripset C-1P over damp or green concrete, provided there is no ponding or standing water. This can help maintain project schedules on site.
No, Gripset C-1P must be tiled over in swimming pools or spas. It is not designed to be an exposed coating in these applications.
A minimum dry film thickness of 2mm is required. Achieve this with 2 trowel coats (1.5mm wet film each) or 3 roller coats (1.0mm wet film each).
| Application | Key benefit | Primary trades |
|---|---|---|
| Basement walls, internal and external | Withstands up to 5 bar positive and 1.5 bar negative hydrostatic pressure, preventing water ingress in critical underground structures. | Waterproofers, builders, civil contractors |
| Potable water storage facilities and tanks | AS 40200 approval ensures safety for drinking water contact, providing compliance for essential services. | Waterproofers, plumbers, tank manufacturers |
| Waterproofing under tiles and pavers, internal and external wet areas | Flexible and crack bridging (≥0.75 mm) to accommodate substrate movement, compliant to AS4858 for internal wet areas. | Tilers, waterproofers, builders |
| Retaining walls, planter boxes, earth shelters | Withstands UV light exposure and can be applied over damp or green concrete, allowing flexibility in project sequencing. | Landscapers, builders, waterproofers |
| Lift pits | High hydrostatic pressure resistance and ability to apply over damp concrete reduces downtime and simplifies complex installations. | Waterproofers, lift installers, builders |
Ensure substrates are clean, sound, smooth and free from contaminants such as laitance, dust, oil, grease, curing agents, moss or algae. Fill voids, cracks (≥1 mm to 6 mm), and pitted areas with suitable repair mortar or sealant. Remove structurally unsound layers by mechanical means.
Pre-dampen with a light water mist to saturated surface dry (SSD) condition, avoiding standing water before membrane application.
Mechanically abrade steel-trowelled or burnished concrete to open the surface, clean thoroughly, then pre-dampen or prime with Gripset OP Primer at ~1 L/10 m².
Mix Gripset C-1P powder with clean water using an electric stirrer with a paddle attachment. Always add powder to water to avoid lumps. Achieve a lump-free, homogenous consistency.
Use 4.2 L water per 15 kg bag (approx. 280 mL water/kg powder or 1:3.5 water-to-powder by volume).
Use 3.0 L water per 15 kg bag (approx. 200 mL water/kg powder or 1:5 water-to-powder by volume).
Apply in a minimum of two coats (trowel) or three coats (roller) to achieve a final dry film thickness (DFT) of ≥2 mm. Apply each coat at right angles to the previous coat for uniform coverage.
First coat ~1.5 mm WFT; second coat after recoat time to build to ≥2 mm DFT.
Three coats at ~1.0 mm WFT per coat to achieve ≥2 mm total DFT.
Pre-seal all junctions, movement zones, penetrations, and drains with the specified bond breaker system before main coats.
Embed Elastoproof B50 Joint Band into wet coat, press firmly, then overcoat to encapsulate.
Apply BRW PF Tape centrally over joint; press to remove air pockets before coating.
Allow full curing before exposure to water pressure or immersion. Protect from rain during curing period.
Cure minimum 7 days before positive/negative water pressure exposure.
Cure minimum 10 days before immersion (e.g., pools, tanks).
Wear protective gloves, protective clothing, eye protection (safety glasses or chemical goggles), and face protection. When working with dry powder, wear a respirator to avoid breathing dust.
Use only outdoors or in a well-ventilated area to prevent respiratory irritation from dust/fumes.
Store in original, unopened packaging for up to 12 months. Keep containers securely sealed in a cool, dry, well-ventilated area, away from direct sunlight and freezing conditions. Store locked up. Dispose of contents and container at an authorised hazardous waste collection point according to local regulations.
Correct surface preparation and priming are critical for membrane adhesion and long-term performance, preventing callbacks from delamination.
Surface prep: Ensure surfaces are clean, sound, and free from loose material, dirt, oils, and laitance. Mechanically remove unsound layers. Concrete must cure for at least 28 days, and cement render for 7 days. Point masonry flush and fill all voids or cracks with a suitable repair mortar like Gripset 11Y.
Primer: Optional. On porous concrete, masonry, and mineral substrates, pre-dampen surfaces with a light water mist; avoid standing water. For steel-trowelled or burnished non-porous concrete, mechanically abrade to roughen, clean, and then pre-dampen. Alternatively, use Gripset OP Primer at 1 litre/10m².
Surface prep: Surfaces must be clean, dry, and free from contaminants. Ensure all sheeting is installed to manufacturer specifications and relevant building standards.
Primer: Optional. Pre-dampen lightly, ensuring no standing water, or prime with Gripset OP Primer.
Surface prep: Clean, sound, and dry, free from loose material and contaminants. Fill any defects or voids with appropriate repair materials.
Primer: Optional. Pre-dampen lightly, ensuring no standing water, or prime with Gripset OP Primer.
| Property | Value |
|---|---|
| Form | Light grey powder |
| Colour (Wet) | Dark Grey |
| Colour (Dry) | Dark Brown |
| Operating Temperature | -20°C to +70°C |
| Elongation (AS1145.3) | 37% (Class 1) |
| Tensile Strength (AS1145.3) | >2 MPa |
| Water Vapour Transmission (ASTM E96 Desiccant method) | 0.7 g/m² /24 hours |
| Water Absorption (AS 3558.1) | 9% |
| Crack Bridging (ISO13007-5) | ≥0.75 mm |
| Compliance to AS4858 | PASS |
| Depth of penetration of water under positive pressure 5 bars | No visual penetration below the membrane |
| Water impermeability in negative pressure 1.5 bars | No visual penetration below the membrane |
| Initial Tensile Adhesion Strength | ≥1 MPa |
| Water Immersion Tensile Adhesion Strength | ≥0.5 MPa |
| Freeze/Thaw Tensile Adhesion Strength | ≥0.5 MPa |
Here are some common examples on where Gripset C-1P Cementitious Membrane used by our customers.
