Liquid Membranes Buyer's Guide — TradieCart
Browse liquid waterproofing membranes from Ardex, Durotech, Gripset, Crommelin, Mapei, Tremco, Pasco, Laticrete, Enviro Systems, and more. Undertile, UV-stable, trafficable, and immersion-rated options with fast delivery across Australia.
Membrane Classifications (AS/NZS 4858)
- Class I — Low extensibility (10–59% elongation). Rigid, for stable substrates.
- Class II — Medium extensibility (60–299%). Moderate flexibility for general use.
- Class III — High extensibility (300%+). Maximum crack-bridging — the default for under-tile wet areas.
Popular Products
| Product | Best For |
|---|---|
| Durotech P15 Diamond 15L | Cost-effective Class III acrylic undertile membrane. 400%+ elongation. Internal and external wet areas, balconies, planter boxes. Blue and grey. |
| Ardex WPM 155 Rapid Plus 20kg | Premium rapid-dry hybrid — tile-ready in 4 hours. Class III. Covers 17.5m² over two coats. STB Tape system included. |
| Gripset 38FC 15L | SBR fast-cure — most widely stocked membrane on TradieCart (6 vendors). Recoat 1 hour, tile over 4 hours. Also in 5L. |
| Mapei Mapelastic Smart 30kg | Two-component cementitious mortar for balconies, terraces, and swimming pools. High flexibility. Apply at 2mm minimum. |
| Crommelin Wetite 15L | Proven SBR undertile membrane — no priming required on sound substrates. Green colour for easy coverage inspection. Also available as Wetite Rapid. |
| Ardex WPM 002 40kg Kit | Two-part cementitious for permanent immersion — pools, spas, tanks. Fibre reinforced, no mat needed. Tile-ready 16–24 hours. |
| Gripset P39 Grey 15L | Polyurethane hybrid — UV resistant, trafficable. Exposed or under-tile on roofs, parapets, balconies. Solvent free. |
| Laticrete Hydro Ban 15L | Self-curing liquid rubber — no mixing, no fabric at corners. Class III. Immersion-rated for pools and steam rooms. Covers 18m². |
| Pasco Aquaproof 115 UV 15L | Moisture-curing PU — UV stable, trafficable, self-levelling. For exposed rooftops, podiums, and walkways. |
| Tremco TREMproof 201/60R 18.9L | Moisture-cure PU for structural waterproofing — retaining walls, below-grade, tunnels. Primer-less on most concrete. |
Quick Recommendation Guide
- Standard bathroom on concrete → Durotech P15 Diamond for value, or Ardex WPM 155 Rapid Plus for same-day tiling
- Fast-cure — tile the same day → Gripset 38FC — recoat 1 hour, tile over 4 hours
- Swimming pool or spa → Ardex WPM 002 cementitious or Laticrete Hydro Ban — both immersion-rated
- Exposed balcony or rooftop → Gripset P39 or Pasco Aquaproof 115 UV — UV stable and trafficable
- Below-grade or retaining wall → Tremco TREMproof 201/60R moisture-cure PU
Common Questions
How many coats do I need? — Minimum two coats, with the second applied at 90 degrees to the first. Use a wet film gauge to verify thickness.
What is the difference between Class I, II, and III? — Elongation at break under AS/NZS 4858. Class III (300%+) is the standard for under-tile wet areas. Higher class means more flexible, not automatically better.
Can I tile over every liquid membrane? — No. Acrylic, SBR, and water-based PU membranes are designed for tiling over. Moisture-cure PU and bituminous membranes are not — check with the manufacturer.
Do I need to prime first? — Usually yes. Some products are self-priming on clean concrete (e.g., Crommelin Wetite, Tremco TREMproof 201/60R). Always prime fibre cement and porous substrates.
Can I use an internal membrane on a balcony? — No. External applications require UV-stable products tested to AS 4654. Internal-only membranes will degrade from UV exposure.
Brands We Stock
We carry liquid membranes from Ardex, Durotech, Crommelin, Gripset, Mapei, Enviro Systems, Tremco, Pasco, Laticrete, Demtech, Bostik, Sika, Davco, Dribond, Drizoro, Kerakoll, and more — with same-day dispatch in Metro Melbourne.