When a waterproofing failure isn't an option, a robust, elastomeric membrane gives long-term peace of mind. Duram 195 delivers seamless, Class III waterproofing that handles movement and remains intact under screeds, tiles, or in below-ground conditions. It ensures a continuous barrier, preventing costly callbacks and structural issues from moisture ingress.

Why this product exists

Duram 195 is a single-pack, moisture-curing polyurethane membrane engineered for high-performance waterproofing. It forms a tough, seamless Class III elastomeric barrier, primarily designed for areas not exposed to direct UV light. Integrated UV stabilizers, absorbers, and antioxidants offer enhanced durability compared to conventional aromatic polyurethanes. This formulation provides a flexible solution for both above and below-ground applications, preventing issues like re-emulsification, blistering, or cracking that plague lesser membranes.

The numbers that matter

• 400% Elongation at Break: This Class III rating under AS4654.1 means the membrane can stretch significantly without failing. It accommodates substantial substrate movement, crucial for long-term waterproofing integrity in dynamic structures.
• 1.04 MPa Tensile Strength: A high tensile strength indicates the cured membrane is tough and durable. This resilience resists puncture and damage from subsequent trades or protection layers, maintaining the waterproofing barrier.
• <100 g/L VOC: Meeting Green Star environmental criteria, this low Volatile Organic Compound content supports healthier indoor air quality. It allows for specification on projects requiring sustainable building materials.
• 1.5 mm Dry Film Thickness (DFT): Achieved in a minimum of two coats, this specified thickness ensures a robust and continuous waterproofing layer. This density of material is key to its long-term performance and resistance to water ingress.

What it's like to use

Duram 195 applies easily as a single-pack, self-leveling liquid, eliminating the need for on-site mixing. It can be applied by brush, roller, broom, or squeegee, with subsequent coats typically applied a day apart. The surface must be clean, sound, and completely dry before application. Moisture content in cementitious substrates requires testing, with less than 75% RH (ASTM F2170) or 4.5% (ASTM F2659) being critical for proper adhesion and to prevent bubbling.

• Priming: Most surfaces require priming. For general use, Duram Primeseal MC or Duram Primeseal SP are recommended. Metal surfaces require Duram ME Primer. If entrapped moisture is a risk, a two-coat application of Duram Primeseal MC helps mitigate bubbling.
• Thinning: For viscosity adjustment, Duram 195 can only be thinned with Duram Solvent, up to 1 litre per 15 litre pail. Using any other solvent will compromise product performance and lead to failure.
• Clean-up: Equipment should be cleaned immediately with Duram Solvent. Spills are difficult to remove once cured, particularly on porous surfaces.

Where this product excels

• Internal Wet Areas: Provides a seamless, Class III membrane under screeds and tiles in bathrooms, laundries, and kitchens. Its bitumen and tar-free formulation prevents unsightly staining of grout or tiles, a common issue with inferior membranes.
• External Balconies, Decks, and Podium Slabs: When protected by a topcoat of Multithane ATC, Duram 195 offers durable, elastomeric waterproofing for external trafficable areas. It accommodates structural movement and withstands environmental exposure without re-emulsification.
• Roofs and Gutters: As part of a system with a Multithane ATC topcoat, it delivers a robust, UV-stable solution for exposed roof surfaces and critical gutter linings, ensuring long-term weather resistance.
• Planters, Retaining Walls, and Water-Retaining Structures: Applied under protection and drainage layers, it provides excellent hydrostatic resistance. This makes it ideal for below-grade applications where ground movement and continuous moisture are present, guarding against expensive leaks.

How it fits in a real system

Duram 195 functions as the primary waterproofing layer in a multi-component system. It is applied after comprehensive substrate preparation, which includes cleaning, laitance removal, and critical moisture testing. Priming with compatible Duram primers is essential for adhesion. For crack and joint treatment, it integrates with detailing solutions such as backer rod and compatible sealants for non-structural cracks, or proprietary systems like Perm-a-fab, Duram Leak-Seal Tape, or DualFlex Bandage for sheet joints.

Once cured, Duram 195 is typically covered. In internal wet areas, an unbonded screed usually follows. For exposed external applications like roofs and decks, Duram Multithane ATC is applied as a UV-stable topcoat. For planters and below-ground structures, protection layers like drainage cell and geofabric are installed to shield the membrane from damage.

Choose this when

• When high-performance, Class III elastomeric waterproofing is required for non-UV exposed areas.
• For internal wet areas where a seamless, bitumen-free membrane is needed under screeds or tiles.
• To waterproof external roofs, decks, or balconies, provided it will be top-coated with Duram Multithane ATC.
• For Green Star rated projects requiring a low VOC waterproofing solution.
• When waterproofing below-ground structures like retaining walls, planters, or pits where hydrostatic resistance is crucial.

Don't use this when

• Not for: Direct, unprotected UV exposure. Duram 195 is an aromatic polyurethane and requires a topcoat like Duram Multithane ATC or full coverage in exposed applications to prevent degradation.
• Not for: Application on damp or slightly damp surfaces. Surface moisture will cause gassing, bubbling, or prevent adhesion. Ensure substrates are completely dry before priming and application.
• Not for: Heavily trafficked areas. This membrane is not designed for continuous pedestrian or vehicular traffic beyond infrequent maintenance foot-traffic during construction.
• Not for: Direct tile adhesion without specific technical advice. Consult Duram for direct stick tile applications to ensure system compatibility.
• Not for: Prolonged contact with chlorine concentrations above 10 ppm, which can degrade the membrane over time.