Belzona 3131 (WG Membrane)

A liquid applied roof coating for long-term protection and waterproofing of roofs which can be applied during winter weather conditions.   

Belzona 3131 (WG Membrane)

Designed for application in all weather conditions, this cold-applied liquid coating offers long-term repair and protection to all types of roofs.

The moisture activated urethane roof coating, Belzona 3131 (WG Membrane), bonds strongly to all types of roofing materials and will not be damaged by rain even immediately after application. The applied system incorporates a reinforcement sheet to allow the easy control of the coating thickness during application and it adapts to roof movement due to its outstanding elasticity.

Key benefits:

  • Provides quick rain resistance – fast cure properties ensure the roof will be immediately watertight
  • Provides long-term roof protection
  • Can be applied down to 0°C (32°F)
  • Microporous structure allows trapped moisture to escape whilst providing long-term weatherproofing protection
  • Lightweight material, will not overload existing structures
  • Excellent adhesion to a wide range of materials including felt, asphalt, lead, zinc, cooper, glass, concrete and brick
  • No conditioner required to porous surfaces including asphalt and mineral felt
  • Adapts to roof movements due to its outstanding elasticity
  • Can be easily applied by brush and roller with no mixing required
  • Application and cure at cold temperatures - no hot work involved

Applications for Belzona 3131 (WG Membrane) include:

  • Creation of waterproof and weatherproof roof surfaces
  • Long-term roof leak repair and protection of deteriorated gutters
  • Sealing of glazing bars
  • Weatherproofing around upstands and other roof protrusions such as skylights, chimneys and vents
  • Replacement of damaged or missing flashings
  • Sealing of gaps and joints on coping stones as well as roof parapet walls
  • Tank base sealing
Key technical data:
Working life at temperatures between 5°C (41°F) to 30°C (86°F) Indefinite
Drying time 4 – 6 hours *dependant on ambient conditions including temperature, humidity and wind speed
Tensile strength (BS 2782) 925 psi (6.4 N per sq.mm) 
Water vapour permeability at 20°C (68°F) 25g per sq.m
Recommended coverage rate (per ltr) 10.3 sq. ft. (0.96 sq.m) on concrete and brick,
16.1 sq.ft. (1.5 sq.m.) on asphalt, smooth felt, bitumen and metals
Bonds to Felt, asphalt, lead, zinc, cooper, glass, concrete, brick and many more
Typical applications Roof repair including waterproofing and weatherproofing. Tank base sealing. 
Unit size 1ltr, 17ltr. Pack sizes may vary locally.  
Availability* Europe, North America and South America only

* All products are subject to regional restrictions. Check with your local Distributor for more information


More information:

For more information about Belzona 3131 (WG Membrane) contact us or find your local distributor.

You can apply to join Belzona Connect to access additional information including SDS and instructions for use.

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