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On Queensland sites since 1989, N-40 is the trusted staple for reliable sealing. It handles everything from commercial kitchens to roofing, delivering waterproof, mould-resistant joints across diverse substrates. Finish the job knowing you have a compliant, versatile silicone that simply works.
N-40 was engineered for broad utility. It combines robust adhesion across common building materials with critical anti-fungal properties, making it indispensable for environments from humid wet areas to external roofing. This neutral-curing formulation ensures compatibility and durability where many general sealants fail, providing a single, reliable solution for a multitude of sealing demands. We developed N-40 based on decades of real-world site feedback, ensuring it performs where it matters most.
N-40 is a ready-to-use, single-pack neutral (oxime) cure silicone. Apply it when temperatures are between 5°C and 40°C. Ensure all surfaces are clean, dry, and free of contaminants. For impervious substrates, use the two-wipe process with Acetone or 100% White Spirits. Masking joint edges before application helps achieve a clean finish.
For optimal adhesion, apply a primer: Adheseal 50A Surface Prep for non-porous surfaces or Everflex Supaprime for porous substrates. Tool off the sealant within approximately 15 minutes of application, before a skin forms, using a moistened spatula. Remove masking tape while the sealant is still wet. Clean uncured product and tools with white spirit.
Control joint depth for joints greater than 10mm with an Adheseal backer rod, choosing one 25% larger than the joint width. Prevent three-sided adhesion by ensuring the sealant bonds only to two surfaces, using a polyethylene tape or release agent where necessary.
N-40 often serves as the final sealing component in various construction assemblies. In wet area installations, after substrate preparation and tiling, it forms the critical flexible, mould-resistant seal between wall and floor joints. For roofing and cladding, it's typically applied after metal sheet installation, sealing laps and penetrations to complete the weatherproofing envelope. Always ensure proper joint design with an Adheseal backer rod and the recommended primer (Adheseal 50A Surface Prep or Everflex Supaprime) to maximise adhesion and movement capability.
N-40 represents exceptional versatility, performing across a vast range of general-purpose sealing applications. It is the indispensable choice for jobs without highly specific, niche requirements, providing a robust, multi-substrate, and compliant sealant. In contrast, Dowsil 795 Silicone Sealant is engineered specifically for high-performance structural glazing applications, demanding precise engineering and stringent regulatory compliance. Choose N-40 for your everyday, high-demand sealing needs, and reserve N-80 for critical architectural structural glazing where its specialised properties are essential.
Yes, N-40 is an anti-fungal silicone specifically designed for hot and humid environments. It resists mould and mildew, making it suitable for shower walls, floors, commercial kitchens, laundries, steam rooms, and spas.
No, it is not suitable for horizontal walkways or other trafficable areas. For natural stone, a stain testing program is recommended before application to ensure compatibility and prevent discolouration.
N-40 uses a neutral (oxime) curing system, which is non-corrosive. This formulation ensures it will not corrode galvanised, zinc-coated steel, or concrete, offering reliable sealing on these sensitive substrates.
Yes, it is formulated to perform reliably across a wide temperature range from -50°C to +150°C. It is also suitable for permanent UV exposure, making it ideal for external applications like roofing.
| Application | Key benefit | Primary trades |
|---|---|---|
| Sealing joints in commercial kitchens and laundries | Inhibits mould and biological growth, meeting green star criteria, ensuring hygiene and durability in wet areas. | Commercial fitters, plumbers, tilers |
| Flexible sealing on roofing (e.g., Colourbond, galvanised steel, Zincalume) | High elasticity (±30% movement) handles structural shifts and thermal expansion. Neutral cure prevents corrosion on metal substrates. | Roofers, plumbers, builders |
| Joints in marine environments and vehicle fabrication | Withstands temperature extremes (-50°C to +150°C), suitable for below-waterline applications (once cured) and provides high permanent flexibility. | Boat builders, vehicle fabricators, transport industry |
| Sealing shower walls and floors, steam and spa rooms | Anti-fungal properties prevent mould and mildew in hot, humid conditions, maintaining a waterproof and flexible joint. | Tilers, plumbers, bathroom renovators |
| General construction and civil applications | Broad adhesion to common building materials, including concrete, glass, and timber, with a low VOC, non-toxic formulation for internal and external use. | General builders, civil contractors, shopfitters |
Surfaces must be structurally sound, stable, dry, and free of dust, loose material, oils/grease, release agents, curing compounds, and other contaminants.
Use a two-wipe process with clean cloths. A suitable cleaner/solvent such as white spirits may be used; change cloths frequently to avoid spreading contamination.
Ensure concrete is cured for at least 28 days and fully dry. Remove dust/friable material so the sealant can key properly.
An adhesion test is recommended. Where primer is necessary, apply with a small brush and allow several minutes for solvent evaporation before sealing.
Use Primer 50A where required after testing.
Use Primer 2001 where required after testing.
Aim for a 2:1 width-to-depth ratio where possible. Internal joints: minimum 5 mm width/depth; external joints: minimum 10 mm. Maximum joint width is 30 mm and depth 15 mm.
For joints greater than 10 mm deep, use a closed-cell polyethylene backing rod about 25% larger than the joint width to control depth.
On flat joints, use a polyethylene tape or release agent so the sealant bonds to two sides only—movement works as designed.
Apply between 5°C and 40°C (installation guide). Cut the nozzle at 45°, keep the tip in contact with both sides of the joint, and apply by pushing sealant ahead of the nozzle to force it firmly into place.
Tool off with a moistened spatula before skin forms (tooling window ~5 minutes) for a smooth joint.
While wet, clean tools and spills with white spirit. Once cured, removal is by mechanical means.
WARNING: This material is hazardous according to health criteria of Safe Work Australia. It may cause an allergic skin reaction and causes serious eye irritation.
Personal protective equipment (PPE) must be suitable for the nature of the work and any hazard identified by risk assessment. Ensure eyewash stations and safety showers are close to the workstation.
Natural ventilation should be adequate under normal use conditions. Avoid inhalation of vapour, mist, or aerosols.
Store in a cool, dry, well-ventilated place out of direct sunlight, between 10°C and 35°C. Keep container tightly closed and upright. Keep away from foodstuffs and incompatible materials. Shelf life is 18-24 months in original packaging. Dispose of contents and container in accordance with local, regional, national, and international regulations.
Proper surface preparation is critical for strong, lasting adhesion. Follow these guidelines to ensure optimal performance of N-40.
Surface prep: All surfaces must be structurally sound, stable, dry, clean, and free of dust, loose material, oils, grease, and other contaminants. For impervious substrates, use the two-wipe process with Acetone or 100% White Spirits, changing cloths frequently. Mask joint edges for a cleaner finish.
Primer: Optional. Adhesion testing is recommended. Apply Adheseal 50A for non-porous surfaces or Everflex Supaprime for porous substrates with a small brush, allowing several minutes for solvent evaporation before sealant application.
Surface prep: Concrete must cure for at least 28 days to prevent mould growth or adhesion failure. Ensure surfaces are free from surface water and continual dampness, and follow general cleaning guidelines above.
Primer: Optional. Adhesion testing is recommended. Use Everflex Supaprime for porous concrete surfaces.
| Property | Value |
|---|---|
| Type of Product | Polysiloxanes |
| Curing System | Oxime |
| Density (Specific Gravity) | 1.03 g/cm3 (Translucent) |
| Shore A Hardness | 20 |
| Elongation at Break (ISO 8339) | 300% |
| Application Temperature | +5°C to +35°C |
| Storage Temperature | 10°C to 35°C |
| Temperature Resistance | -50°C to +150°C |
| Fire Tested | AS/NZS 1530.3-1999 Smoke Developed Index of 0-1 |
| Movement Capability | ±30% |
| Elastic Recovery (ISO 7389) | >90% |
| VOC Content | 43 gm/lt |
| Best Before | 18-24 months in original packaging |
| Cleanup Uncured | White spirit or turpentine |
| Skin Time | Approximately 15-20 minutes |
| Cure Time | 2mm per day at 25°C & 50% humidity |
| Form | Viscous Liquid |
| Odour | Faint odour |
| Solubility | Immiscible in water |
| Specific Gravity (SDS) | ~1.05 Kg/L |
| Pour Point/Range | > 0°C |
Here are some common examples on where Adheseal N40 used by our customers.
