Solvent-based waterproofing membranes are high-performance liquid systems that use chemical solvents for fast drying, strong adhesion, and excellent water resistance. Ideal for areas needing tough, durable waterproofing, they offer flexibility and UV resistance—but require careful handling due to fumes and flammability.
Solvent-based membranes are liquid-applied waterproofing systems that rely on chemical solvents (like xylene or toluene) as carriers. When applied, the solvent evaporates quickly, leaving behind a rubbery, waterproof film. These membranes are popular for their quick drying times, strong adhesion, and resistance to harsh weather and water pooling.
| Feature | Solvent-Based Membranes | Water-Based Membranes | Sheet Membranes |
|---|---|---|---|
| Drying Time | Fast (30 mins – 2 hrs) | Slow (4–12 hrs) | No drying needed |
| Cure Type | Solvent evaporation | Water evaporation | Pre-cured sheets |
| Flexibility | Excellent | Moderate–Good | Varies |
| UV Resistance | Often high (with topcoat) | Varies | Depends on sheet type |
| Application | Brush, roller, or spray | Brush/roller | Torch-on or peel-n-stick |
| Odour | Strong solvent smell | Low odour | No odour |
| Ventilation Needed | Yes – well-ventilated areas only | Not always | N/A |
| Substrate Tolerance | Better with damp/porous surfaces | Needs dry conditions | Clean/dry surface needed |
Solvent-based membranes are typically used in:
Flat roofs and balconies
Retaining walls (external face)
Under screeds or topping slabs
Planter boxes (with proper protection)
Exposed trafficable areas (when topcoated)
Podiums and car parks
Substrates must be clean, dry, and free from dust, oil, or laitance.
Some brands allow application on slightly damp concrete, but no ponding water should be present.
Primer is recommended for porous surfaces like concrete or masonry.
Roller or brush for detail work and small areas.
Airless spray for large open surfaces.
Apply in two or more coats (minimum recommended thickness varies by brand, e.g., 1.2mm–1.8mm dry film thickness).
Touch dry: 30 minutes to 2 hours depending on ambient temperature, wind, and humidity.
Recoat time: 1–3 hours (check product datasheet).
Full cure: 24–72 hours depending on temperature and coating thickness.
Best applied in temperatures between 10°C and 35°C.
These are flammable products – keep away from open flames, smoking areas, or heat sources.
Use only in well-ventilated areas; ensure adequate PPE (respirator, gloves, goggles).
Solvents will emit strong fumes – indoor use requires mechanical ventilation.
Fast drying time: Saves labour time and project delays.
Excellent adhesion: Bonds well to concrete, metal, and primed surfaces.
Durable & flexible: Can handle minor substrate movement.
Resists ponding water: Great for flat roofs and balconies.
UV resistant: Can be left exposed with or without a protective topcoat.
Not suitable for poorly ventilated areas unless mechanical extraction is used.
Strong odour during application.
Flammable – strict storage and transport requirements.
Cannot be applied in wet or rainy conditions.
Always ensure your installer uses a licensed system, and request the Product Data Sheet (PDS) and Safety Data Sheet (SDS).
Ask if your membrane requires a UV topcoat or additional protection layer.
If applying under tiles or screed, check compatibility with adhesives and screeds.
Solvent-based membranes are like the “heavy-duty jackets” of the waterproofing world. They’re tough, flexible, and fast-drying—but need to be handled with care. When applied correctly, they provide long-lasting protection, especially in areas exposed to harsh weather and pooling water.
