SUPAPRO 425 is a hybrid polyurethane, elastic joint sealant that can be painted once cured.

Building approved BS5889

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SUPAPRO 425 is a hybrid polyurethane, elastic joint sealant that can be painted once cured. Meets requirement for ASTM C719 with movement capability of ±25% with a Shore A Hardness of 30. Perfect for internal and external use and safe for the applicator as does not contain solvents or isocyanates like traditional polyurethane sealants.



  • Isocyanate & Solvent Free
  • Superior UV Resistance
  • Non Slumping
  • Non Bubbling Formulation
  • Highly Elastic ±25%
  • Excellent weather proofing properties
  • Paintable



Ideal for use as a joint sealant for expansion, movement and perimeter joints with strong adhesion to most building materials, timber, concrete, fibre cement, plasterboard, brick and block work, sandstone, granite, metals including aluminium, steel, lead, zinc, common plastics including fibreglass, polystyrene, PVC.


TechnologyHybrid Polyurethane
Shore A Hardness30
Tensile Strength (MPA)>1.0
Elongation at Break200-400%
Joint MovementHighly Elastic ±25%
Cure Time

>2 mm/24h
Application Temp

5°C to 50°C
Density (g/cm3)1.6 ± 0.05



  • most building materials
  • timber
  • concrete
  • fibre cement
  • plasterboard
  • brick and block work
  • sandstone
  • granite
  • metals including aluminium, steel, lead, zinc
  • common plastics including fibreglass
  • polystyrene
  • PVC



All surfaces must be clean, dry, sound and free from wax, dust, oil, rust, grease or any other contamination prior to the application of SupaPro 425. For best results clean non porous surfaces prior with IPA or Prosil Cleaner 1


Sausage 600ml
Concrete GreyGrey Silicone Sealant
WhiteWhite Silicone Sealant
BlackBlack Silicone Sealant

* Colours may vary without notice or be unavailable. Please call your local representative or office to find out more