Sikasil 825 Silicone Sealant

Sikasil 825 is a premium low modulus, neutral cure, alkoxy silicone sealant for a wide range of construction joint sealing applications. Its low modulus means it is highly elastic and accommodates large joint movements without exerting stress on the bonded substrates, critical for perimeter glazing, uPVC window and door installations, and façade expansion joints. The neutral cure mechanism means it does not release acetic acid on curing, making it safe for use on sensitive surfaces including soft metals (lead, copper, zinc), marble, and natural stone. Excellent adhesion to a wide range of both porous and non-porous surfaces without priming in most cases. Excellent external weathering and UV resistance over many years' exposure. Certified to EN15651 and ISO11600. Available in up to 13 colours.

Benefits

• Low modulus for maximum flexibility, accommodates large joint movements without stressing the substrate
  
• Neutral cure, no acetic acid release, safe on soft metals, natural stone and marble
  
• Excellent adhesion to glass, metals, plastics, wood (painted or unpainted), uPVC and polycarbonate
  
• Excellent long-term external weathering and UV resistance
  
• Available in up to 13 colours for discrete architectural colour-matching
  
• Certified to EN15651 (façade, glazing, sanitary, cold climate) and ISO11600
  
• CE/UKCA marked | ASTM C719 Class 35
  

Good to know

• Maximum joint width 50mm, joint depth 50% of width (minimum 5mm)
  
• Does not require primer on most surfaces, conduct adhesion test before large-scale application
  
• If joint is likely to be immersed or adhesion is poor on porous surfaces, use Sika Primer 3N
  
• Not suitable for aquariums, swimming pool joints, or use in conjunction with bitumen/asphalt
  
• Not overpaintable
  
• Use a joint backer rod to control joint depth on wider joints
  
• Store between +5°C and +25°C in original sealed containers
  
• Clean uncured sealant with white spirit; cured material must be removed mechanically