Protecting underground and external structures from persistent moisture, corrosion, and rot demands a proven solution. When specifying an economical, reliable membrane that offers both robust waterproofing and durable protective coating, Gripset 51 provides the flexibility and adhesion needed. It ensures critical assets remain sealed and sound against the elements.
Gripset 51 is formulated as a versatile, solvent-free bitumen-rubber liquid membrane. It exists to provide a flexible and economical solution for challenging underground and external waterproofing jobs. This product excels at forming a seamless barrier that withstands continuous damp conditions and acts as a long-lasting protective coating against corrosion, rot, and salt damp on timber and metal surfaces.
Gripset 51 is applied by brush or medium nap roller, with a minimum of two coats. Achieving the specified 1.0 mm dry film thickness is crucial; a wet film gauge helps regulate coverage. For effective application, prepare surfaces by ensuring they are clean, sound, and free from contaminants. Porous surfaces require priming with a 1:3 diluted mix of Gripset 51 and water, while non-porous surfaces use a 1:1 dilution, or Gripset OP Primer. For mineral surfaces with residual moisture or rising damp, Gripset E-60 Primer acts as a suitable primer.
The product has a recoat time of 2-4 hours, allowing efficient multi-coat application. Backfilling can occur after 5 days, with full cure achieved in 10 days for flood testing or full service. Wet product cleans up with water; dried material requires mechanical removal.
Gripset 51 can also be mixed with a 3:1 sand-cement mortar for high-build applications like forming waterproof fillets in planter boxes (1 part Gripset 51 to 1 part mortar). For low-build applications that enhance filling properties or accelerate drying in colder conditions, a 3 parts Gripset 51 to 1 part mortar mix is used.
Gripset 51 is typically applied as the primary waterproofing layer or protective coating in external and underground systems. Its position requires careful attention to detailing at critical points. For pipes and penetrations, ELASTOPROOF COLLARS are fitted into a wet coat of Gripset 51. Alternatively, BRW PF TAPE can form flanges, or RLA MAX SMP 25 sealant can seal around the base of penetrations. For static cracks up to 6mm, RLA MAX SMP 25 sealant fills the crack, reinforced with strips of RLA Waterproofing Bandage or Elastoproof B50 Joint Band. Bond breaker systems like ELASTOPROOF B50 JOINT BAND or BRW PF TAPE are encapsulated within two coats of Gripset 51 at joints and junctions, ensuring continuous flexibility and waterproofing performance.
Gripset 51 offers a flexible, bitumen-rubber solution for demanding underground and external waterproofing, and heavy-duty protective coating tasks. It delivers excellent sealing and adhesion across various building surfaces, especially where continuous damp conditions or corrosive environments are a concern. In contrast, products like Gripset C-1P Waterproofing Membrane provide a different chemistry, typically favouring masonry and concrete substrates, often for under-tile applications or where a rigid, breathable system is preferred. Gripset 51 is explicitly not for trafficable finishes, immersed applications, or internal areas requiring direct tiling or other surface finishes, making its application focus distinctly external and protective.
No, Gripset 51 is not suitable for applications involving continuous immersion. It is designed for continuously damp environments and external/underground areas, but not constant water submersion.
Gripset 51 is effective on concrete, render, masonry, compressed fibre cement, marine ply, timber, galvanised iron, zincalume, bituminous, asphalt, and polystyrene. All surfaces must be primed according to specific guidelines before application.
Yes, Gripset 51 offers good crack bridging properties. For static cracks between 1mm and 6mm, they must first be cleaned, filled with RLA MAX SMP 25 sealant, and then reinforced with waterproofing bandage or joint tape before membrane application.
A minimum of 1mm dried film thickness is required, achieved by applying at least two coats. This translates to a total minimum coverage of 1.5 litres per square metre, ensuring robust waterproofing performance.
| Application | Key benefit | Primary trades |
|---|---|---|
| Waterproofing retaining walls and underground surfaces | Withstands continuously damp environments and prevents water ingress. | Waterproofers, builders, landscapers |
| Sealing external cellar and basement walls | Provides flexible protection against moisture with high adhesion to masonry. | Waterproofers, builders, renovators |
| Lining planter boxes and garden beds | Protects against water damage and rot in soil-filled conditions. | Landscapers, builders |
| Repairing gutters | Bonds to existing bitumen/asphalt surfaces for efficient repairs. | Roofers, plumbers, maintenance teams |
| Protective coating for timber posts | Guards against corrosion, rot, and salt damp for extended service life. | Fencers, builders, rural contractors |
| Coating galvanised iron and zincalume | Offers protection against corrosion on specific metal surfaces. | Roofers, shed builders, maintenance teams |
| Crack bridging on concrete substrates | Elongation >500% Class III accommodates normal substrate movement, preventing failure. | Waterproofers, concrete repairers |
| High-build mortar applications | Forms waterproof fillets and fills voids when mixed with sand/cement, enhancing system integrity. | Waterproofers, bricklayers, concreters |
Substrates must be clean, sound, smooth and dry; free from dust, oil/grease, wax, laitance, curing agents, release agents, moss/algae, loose coatings and sharp protrusions. Concrete must cure ≥28 days; cement render/screeds ≥7 days. Patch voids, pitting and non-structural cracks with compatible repair mortars.
Grind, shot-blast or abrade to remove weak layers and contaminants; vacuum thoroughly.
Degrease where required, rinse, then allow to dry. Ensure no standing water before priming.
Prime the entire application area before membrane installation.
Dilute Gripset 51 at 1:3 (v/v) with clean water; mix to a smooth, homogeneous consistency. Apply liberally by brush/roller.
Dilute Gripset 51 at 1:1 (v/v) with water and apply, or use Gripset OP Primer as an alternative.
Apply Gripset E60 at 1–2 coats (≈1 L/3 m² per coat) over mineral substrates with residual moisture or subject to rising damp.
Pre-detail all joints, junctions, movement zones, penetrations, drains and cracks before field coating.
Option A: Embed Elastoproof B50 Joint Band into a wet coat of Gripset 51, then fully encapsulate. Corners: use prefabricated Elastoproof corners.
Option B: Apply BRW PF Tape centrally over joints; roll firmly to expel air and creases.
Option C: Tool a continuous fillet using RLA MAX SMP 25 at floor/wall and horizontal/vertical transitions.
Fit Elastoproof Collars into a wet coat; or form flanges with BRW PF Tape; or seal with RLA MAX SMP 25 and reinforce.
Clean, fill with RLA MAX SMP 25, then overlay with Elastoproof B50/BRW PF Tape/RLA Waterproofing Bandage.
Use blends to create fillets, fill voids, level rough asphalt/bitumen, or assist drying/coverage in cooler conditions.
Mortar: 3 parts sand : 1 part cement (by volume). Pre-wet to a workable mortar, then mix 1:1 (Gripset 51 : mortar) with an electric stirrer. Trowel/spatula to thickness.
Use the same 3:1 sand:cement mortar. Pre-wet, then blend 3:1 (Gripset 51 : mortar). Apply by brush/roller at specified coverage.
Apply Gripset 51 by brush or medium nap roller in two coats.
Apply at 750 µm wet film thickness (WFT). Work methodically; maintain uniform coverage.
Recoat after 2–4 hours (at 23 °C, 50% RH). Apply at 750 µm WFT perpendicular to the first coat. Target total DFT ≈1.0 mm (≈1.5 L/m² total).
Clean tools with water while wet. Dried product requires mechanical removal. Store sealed pails out of direct sun at room temperature; avoid freezing.
Record substrate condition, primer used, tape/band details, WFT readings per coat, recoat intervals and weather conditions.
WFT gauge readings logged by area; confirm target DFT ≈1.0 mm and coverage ≈1.5 L/m².
Confirm minimum 5 days before backfill and 10 days before flood testing at 23 °C/50% RH.
Wear safety shoes, overalls, gloves (nitrile rubber recommended for intermittent contact), and safety glasses.
Natural ventilation is adequate under normal use conditions. Ensure good ventilation in confined spaces.
Store in a cool, dry, well-ventilated place, out of direct sunlight, and away from incompatible materials. Keep containers closed and check for leaks. Avoid freezing conditions and cold floors. Best stored at room temperature. Shelf life is 12 months in original unopened packaging. Dispose of material and container according to local regulations.
Proper surface preparation and priming are critical for Gripset 51 to bond correctly and deliver long-term protection.
Surface prep: Surfaces must be clean, sound, smooth, and dry. Remove all loose material, dirt, dust, oil, grease, wax, laitance, and existing coatings. Masonry must be pointed flush. Fill voids, holes, pitted sections, and non-structural cracks. Concrete requires a minimum 28-day cure, and cement render/screeds a 7-day cure.
Primer: Required. For porous/absorbent surfaces, use Gripset 51 diluted 1:3 with water. For damp or moisture-sensitive mineral surfaces (residual moisture >80% RH or 5% moisture content, or subject to rising damp), use Gripset E60 at 1 litre per 3m² per coat.
Surface prep: Ensure surfaces are clean, sound, smooth, and dry. Remove any loose material, dirt, dust, oil, grease, or existing coatings. Timber posts should be free from rot or significant degradation.
Primer: Required. For porous/absorbent surfaces, use Gripset 51 diluted 1:3 with water.
Surface prep: Surfaces must be clean, dry, and free from oil, grease, rust, or other contaminants. Mechanically remove any unsound layers.
Primer: Required. For non-porous/non-absorbent surfaces, use Gripset 51 diluted 1:1 with water. Alternatively, Gripset OP Primer can be used.
Surface prep: Clean surfaces thoroughly, removing loose material, dirt, and any failed aged coatings. Ensure the substrate is sound and dry.
Primer: Required. For non-porous/non-absorbent surfaces, use Gripset 51 diluted 1:1 with water. Alternatively, Gripset OP Primer can be used.
Surface prep: Ensure the surface is clean, dry, and free from dust or contaminants. The polystyrene must be sound and securely fixed.
Primer: Required. For porous/absorbent surfaces, use Gripset 51 diluted 1:3 with water.
| Property | Value |
|---|---|
| Form | Viscous Liquid |
| Colour | Wet: Charcoal, Dry: Black |
| Specific Gravity | 1.15 kg/litre |
| Shore A Hardness (ASTM D2240-97) | 52 |
| Elongation (AS1145.3) | >500% Class III |
| Tensile Strength (AS1145.3) | >2 MPa |
| Water Absorption (AS 3558.1) | 1.6% |
| Water Vapour Transmission (ASTM E96 Desiccant method) | 1.2 g/m²/24 hours |
| Re-coat Time | 2-4 hours |
| Backfilling Time | 5 days |
| Full Cure / Flood Test Time | 10 days |
| Minimum Film Thickness | 1.0 mm (dry) |
| Minimum Coverage | 1.5 litres/m² (total, 2 coats) |
| Shelf Life | 12 months |
Here are some common examples on where Gripset 51 Membrane used by our customers.
