Adheseal N40 Silicone Sealant Aluminium Grey

For sealing roofing, plumbing, and wet areas where joint movement and biological growth are constant challenges, N40 Silicone Sealant Aluminium Grey provides a highly flexible, non-corrosive barrier. This neutral-cure oxime silicone forms a waterproof rubber seal that accommodates joint movement without losing adhesion, making it suitable for both internal and external environments.

What it does

N40 Silicone Sealant Aluminium Grey is a single-pack, neutral-curing silicone formulated with added fungicide to inhibit mould and biological growth in hot, humid environments such as commercial kitchens, laundries, steam rooms, and showers. Because it is an oxime-curing system, it is non-corrosive and will not degrade concrete, zincalume, colourbond, or galvanised steel. Once fully cured, the sealant is suitable for below-waterline applications and maintains its properties across temperature extremes from -50°C to +150°C.

Numbers that matter

• ±30% movement capability: High elastic recovery (greater than 90% ISO 7389) allows the cured joint to expand and contract under structural stress without cohesive or adhesive failure.
• 2mm per day cure rate: Cures at 2mm per day (tested at 25°C and 50% humidity) with an initial skin time of approximately 20 minutes to prevent dust pickup.
• 43g/L VOC: Low-odour formulation that meets Green Star environmental criteria and conforms to the Californian Bureau of Air Quality Management Rule 1168.
• AS/NZS 1530.3-1999: Tested to fire standards with a Smoke Developed Index of 0-1.

Where to use it

N40 Silicone Sealant Aluminium Grey adheres to most common construction substrates, including:

• Zincalume, colourbond, aluminium, and galvanised metal
• Glazed and unglazed ceramic tiles, porcelain, and enamel
• Glass and fibreglass
• Timber and laminated kitchen benches
• PVC and most common building surfaces

Limitations

• Do not use in totally confined spaces, as the sealant requires atmospheric humidity to cure.
• Do not use for structural glazing (use N-80 or N-60 Glazing silicone instead).
• Do not use for adhering mirrors (use High Power 609 instead).
• Not suitable for use in aquariums or continuous underwater applications like swimming pools.
• Not suitable for horizontal walkways and trafficable areas.
• Do not use on polycarbonate sheeting or composite panels (PU50FC is recommended instead, subject to testing).
• May discolour copper and brass.
• Do not paint. This silicone is not paintable.
• Do not use on stone without first conducting a stain testing program.
• Do not clean or treat the sealant with solvents or cleaning agents that may affect or discolour the product, especially during its curing phase.

Installation and joint design

Apply when substrate and air temperatures are between 5°C and 40°C. All surfaces must be clean, dry, and free of grease, form release agents, curing compounds, or surface water. Concrete must cure for a minimum of 28 days before sealant application to prevent adhesion failure and subsequent mould growth. For impervious substrates, clean using the two-wipe process with Acetone or 100% White Spirits.

For optimal movement performance, design joints to a 2:1 width-to-depth ratio:

• Internal joints: Minimum width and depth of 5mm.
• External joints: Minimum width and depth of 10mm.
• Maximum limits: Maximum joint width is 30mm; maximum depth is 15mm.
• Three-sided adhesion: Prevent three-sided adhesion on flat joints by using a polyethylene backing rod or release tape to restrict bonding to two sides only. Use a backing rod 25% larger than the joint width for joints deeper than 10mm.

Where priming is required, use Primer 50A for non-porous substrates and Everflex Supaprime for porous substrates, allowing the solvent to evaporate for several minutes before gunning the sealant.