For sealing expansion and construction joints in precast panels, insitu concrete, brickwork, and metal cladding, Bostik Seal ‘N’ Flex One Plus P590 provides a low-modulus polyurethane seal that accommodates joint movement without tearing or pulling away from the substrate.
This polyurethane sealant is formulated to absorb cyclic expansion and compression movement of +100%/-50%. With an elongation at break exceeding 1,000%, it stretches to prevent adhesive or cohesive failure in high-movement joints, such as those found in aluminium composite materials, fiber cement sheet, and aluminium window installations. The moisture-curing formula prevents the formation of internal bubbles during the curing cycle, ensuring a dense, consistent seal even when applied to damp or moist substrates.
Suitable for joints in:
To ensure correct sealant geometry and prevent three-sided adhesion, always install a backing rod before applying the sealant. The minimum allowable joint depth is 5mm, and the maximum joint width is 80mm. Tool the sealant to achieve a concave surface profile.
For joints 5mm to 10mm wide, maintain a 1:1 width-to-depth ratio. For joints wider than 10mm (up to 80mm), calculate the depth using the formula: Depth = (width in mm / 3) + 6.
The sealant adheres without primer to clean concrete, mortar, and bare aluminium. For optimum adhesion in high-stress joints or under extreme weather exposure, use the following priming procedures:
Bostik Seal ‘N’ Flex One Plus P590 can be painted after curing for a minimum of 7 days. Solvent-containing coatings, such as enamels or oil-based paints, may react with the sealant surface and leave it tacky. Surface coatings may discolour when in direct contact with the cured sealant, or crack due to cyclic joint movement. Conduct a field test to verify coating compatibility.
Yes, Bostik Seal 'N' Flex One Plus P590 is engineered for high-movement joints, accommodating +100% / -50% cyclic expansion and compression. This low modulus polyurethane maintains elasticity with over 1000% elongation at break, preventing failure in dynamic applications.
Bostik Seal 'N' Flex One Plus P590 is suitable for application on damp or moist substrates, which can help keep projects on schedule. Always ensure surfaces are clean and free of contaminants before application to secure optimal adhesion.
Yes, this sealant is certified to AS/NZS 4020:2018 for potable water contact. This makes it suitable for sealing applications where drinking water quality must be maintained, such as water tanks or pipes.
This sealant can be painted after a minimum of 7 days cure. Conduct a field test with solvent-containing coatings, as they may cause tackiness or discolouration. Cyclical movement in the joint may also lead to cracking in rigid surface coatings.
Apply to joints with a minimum depth of 5mm and a maximum width of 80mm. Correct joint geometry, including the use of a backing rod and specific width-to-depth ratios, is critical for performance.
| Application | Key benefit | Primary trades |
|---|---|---|
| Construction and expansion joints in concrete facades | Withstands significant building movement with +100% / -50% joint movement capability. | Concrete contractors, facade installers, builders |
| Sealing joints in precast and tilt-up concrete panels | Forms a bubble-free, flexible seal that remains elastic, crucial for large panel systems. | Precast installers, tilt-up contractors, concrete contractors |
| Perimeter sealing for aluminium windows and metal cladding | Offers UV resistance and paintability, maintaining aesthetic and structural integrity in exposed areas. | Window installers, facade installers, cladders |
| Sealing joints in brickwork and blockwork | Provides a long-lasting, flexible seal that prevents water ingress and accommodates thermal cycling. | Bricklayers, block layers, general builders |
| Sealing GRC, fibreglass, and specialty panel systems | Adheres reliably to a range of challenging substrates, maintaining flexibility to prevent joint failure. | Facade specialists, composite panel installers |
Ensure the joint design is correct (minimum 5mm depth). Insert a backing rod to control sealant depth and prevent three-point adhesion.
Apply sealant in a continuous operation using a caulking gun. Use enough pressure to ensure the joint is properly filled without air gaps.
Tool the surface with a spatula or trowel to achieve a smooth, concave shape. This ensures maximum contact with the joint interface.
Wear safety glasses with side shields or goggles. Wear suitable protective clothing and gloves. A respirator conforming to EN 140 with Type A/P2 filter or better (organic gases and vapours filter conforming to EN 14387) is recommended.
Ensure adequate ventilation during use. Apply in well-ventilated areas.
Store in a cool (between 5°C to 25°C), dry, well-ventilated area, out of direct sunlight. Keep containers tightly closed. Shelf life is 15 months from production date in original unopened packaging. Dispose of waste and contaminated packaging in accordance with local, regional, national, and international regulations. Do not dispose of down drains or into local waterways.
Proper substrate preparation and priming are essential for the long-term performance and adhesion of Bostik Seal 'N' Flex One Plus P590. This guide details requirements for common materials.
Surface prep: Ensure surfaces are clean, dry, and free from contaminants like laitance, oil, dust, and old sealants. Application temperature must be between 5°C and 40°C. Vacuum clean dust and loose particles.
Primer: Not required for optimum adhesion on clean, dry, uncontaminated standard concrete or mortar. For high stress joints or porous surfaces subject to immersion, use Bostik N49 Primer.
Surface prep: Clean and dry thoroughly, removing any foreign matter, grease, or protective coatings. Application temperature must be between 5°C and 40°C.
Primer: Not required for bare aluminium. Always conduct a Pre-Tested Adhesion to Substrate (P.A.T.S.) procedure before full application, especially if protective coatings are present.
Surface prep: Clean surfaces completely, ensuring they are dry and free from any residues or protective films. A non-absorbent substrate will retain a bead of water on the surface.
Primer: Required. Use Bostik N40 Primer with the two-cloth method. Refer to the Bostik N40 Primer Technical Data Sheet for full instructions. Always conduct P.A.T.S.
Surface prep: Clean all surfaces thoroughly. Porous substrates allow water to soak in easily. Ensure backing rod is installed prior to priming.
Primer: Required. Use Bostik N49 Primer for maximum performance on porous surfaces and in all periodically immersed or submerged applications. Refer to the Bostik N49 Primer Technical Data Sheet.
| Property | Value |
|---|---|
| Appearance | 7 colours available |
| Viscosity | Non-sag, smooth thixotropic paste |
| Cure Method | Moisture curing |
| Application Temperature | 5 to 40°C |
| VOC | 2.8 g/L |
| Temperature Resistance | -30 to 80°C |
| Skin Time | 90 mins |
| Cure Rate | 2.5-3mm/24 hours |
| Full Cure | 7 days on porous substrates, >14 days for joints over 20mm wide |
| Specific Gravity | 1.30 g/ml |
| Shore A Hardness | 20-25 (DIN 53505), 27-28 (ASTM C661) |
| Tensile Strength | > 1.0 N/mm² |
| Elongation at Break | At least 1,000% |
| Total Joint Movement | +100% / -50% |
| Maximum Joint Width | Up to 80mm |
| Flash Point | > 100°C |
Here are some common examples on where Bostik Seal ‘N’ Flex One Plus P590 Polyurethane Sealant 600ml used by our customers.
