Duram Azcoseal

For sealing porous sandstone, stabilising friable asbestos sheeting, or priming low-porosity tilt-up slabs before waterproofing, Azcoseal penetrates deeply to bind surfaces and block water penetration. This clear, solvent-based acrylic sealer dries to a semi-gloss satin finish, preventing dust dusting, salt spray damage, and rain penetration while serving as an adhesion-promoting primer for subsequent membranes.

How it works

Azcoseal uses a low-viscosity, solvent-borne acrylic formulation that sinks deep into the pores of masonry, concrete, and cementitious substrates. It incorporates cross-linking technology to lock down loose particles, seal surface pores, and create a tough, resilient film. When used as a penetrative primer, this cross-linking mechanism improves the physical bond of subsequent water-based and polyurethane membranes, including Duram Multithane, Duram 195, Durabit, and Azcothane ranges. For exposed decorative brickwork, sandstone, or pavers, it acts as a weatherproofing barrier that resists UV degradation and minimises dirt pick-up.

Numbers that matter

• 4m² per litre: The standard coverage rate per coat, which must be adjusted upward for highly porous substrates.
• 1 to 2 hours touch dry: Fast drying window at 25°C and 50% relative humidity, allowing quick turnaround between coats.
• 24-hour full cure: The standard timeline to achieve full film properties and chemical resistance under standard conditions.
• 10°C to 50°C service temperature: The operational thermal window the cured acrylic film tolerates once fully dry.

Where to use it

• As a penetrative primer: Applied in a single coat on tilt-up slabs, concrete, cement render, fibre cement sheeting, and Hebel before applying membranes or high-build coatings.
• As a clear weatherproof sealer: Applied in two coats over face brick, brickwork, and blockwork to resist wind-driven rain and salt spray.
• As an encapsulating binder: Applied in two coats worked well into the substrate to bind friable asbestos sheeting and minimise surface fragmentation.
• As a trafficable wet-look finish: Applied in three coats over sandstone, cement pavers, concrete stencil, and masonry.
• As a coating reactivator: Applied over old acrylic coatings and membranes to prepare the surface for recoating.

Limitations

• Not a vapour barrier: Do not use on wet, saturated, seeping, or continually damp substrates, or where there is a risk of entrapped moisture. For these applications, Duram Primeseal MC must be used.
• UV exposure restrictions: Do not use as a primer on substrates where the membrane or the overlay adhered to the membrane is subjected to external UV exposure; Duram Primeseal MC is the preferred primer for these areas.
• Substrate exclusions: Not suitable for metal, glazed tiles, marble, terrazzo, shiny or highly smooth concrete, particle board, or chipboard.
• Discolouration risks: Test areas are highly recommended on pavers and terracotta tiles as the solvent base may dissolve entrapped salts, causing discolouration.
• Moisture hazards: If the area becomes wet before full cure, the coating may turn milky. Cured surfaces may be slippery when wet.
• Bubbling risks: If used as a primer in exposed applications, all solvents must fully evaporate before applying the topcoat to prevent gas bubbling.

Application and surface preparation

Surfaces must be sound, stable, dry, clean, and free of dust, efflorescence, or loose material. Remove efflorescence and wash the area, allowing it to dry fully before application. Clean mould using a water blaster with chlorine, and vacuum any loose debris. Grind cracks to a V-profile and fill with Duram sealant, and fill concrete voids with Duram WB/Primeseal modified mortar. Apply Azcoseal by brush, roller, or spray, ensuring subsequent coats are applied within 24 hours of the previous coat for optimal adhesion. Clean all tools and equipment immediately after use with Duram Solvent before the acrylic cures.