Silicone Sealant

Silicone sealant is a flexible, weatherproof sealant used to seal joints in aluminum or GI cladding and around penetrations, flashings and expansion joints. It keeps water and air out of the insulation system, which is important because wet insulation loses thermal performance and can promote corrosion under insulation.

Cured general-purpose silicone sealant withstands -40°C to +150°C, and high-temperature grades are available for up to +300°C. It stays flexible across this range, which helps it follow thermal movement of cladding. Specify the high-temperature grade when the joint is near hot surfaces.

Neutral-cure silicone sealant releases non-corrosive by-products while curing and is the grade suited to metal cladding, while acetoxy-cure silicone releases acetic acid, the familiar vinegar smell, which can attack some metals. For aluminum or GI cladding joints, neutral-cure is the usual choice.

Silicone sealant is typically tack-free in 15 to 30 minutes and fully cured in 24 to 72 hours. Curing depends on temperature, humidity and bead size, with deeper beads taking longer. Protect fresh joints from rain and movement until they are tack-free.

Silicone sealant has an elongation at break of at least 400%, so it can stretch with expansion and contraction of cladding joints without tearing. This flexibility, together with UV and weather resistance, makes it suitable for outdoor jacketing where joints move with temperature and wind.

Use Butyl Mastic Sealant Tape inside cladding overlaps as a non-hardening gap-filling seal, and silicone sealant on exposed joints, penetrations and flashings. Many outdoor jobs use both: butyl tape under the lap, fixed with Self-Tapping Screw or Insulation Band & Buckles, and silicone to finish visible edges.

Silicone sealant in this catalogue is referenced to ASTM C920 and ISO 11600, standards for elastomeric joint sealants used in building and construction joints. If your project specification requires particular test documentation, mention it in your enquiry and we will confirm what is available.

Silicone sealant is exported under HS code 32141000, which covers caulking compounds and other mastics used as sealants. This is the heading for cartridge and sausage packs of weatherproof joint sealant, whether neutral-cure or acetoxy-cure, general purpose or high-temperature grade.

Silicone sealant comes in 280 ml or 300 ml cartridges and 590 ml sausages, packed in boxes of 12 or 24 cartridges. Colors are white, grey, black, aluminum grey and transparent, with aluminum grey matching aluminum cladding. List the cure type, color, pack and number of boxes in your enquiry.