Belzona 3000 Series

Belzona 3131

Name: Belzona 3131
Brand: Belzona
SKU: FN10064

WG Membrane

FN10064

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

A moisture-activated urethane liquid roof coating immediately rainproof on application and applicable in cold winter conditions.

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SeriesBelzona 3000 Series

Overview of Belzona 3131

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 easy control of the coating thickness during application and it adapts to roof movement due to its outstanding elasticity.

Key Benefits

Rapid Cure

Cures rapidly even at low temperatures for fast back in service time

Long-Term Roof Protection

Provides long-term protection and waterproofing of roofs in excess of 25 years

All Weather Application

Applies and cures down to 0°C (32°F) and even during adverse weather conditions

Microporous Membrane

Allows trapped moisture to escape while providing long-term weatherproofing protection

Lightweight

Lightweight material that will not overload existing structures

Excellent Adhesion

Bonds strongly to virtually any rigid surface

Outstanding Elasticity

Adapts to roof movements and building expansion due to outstanding elasticity

Simple Application

Easy to mix and apply without specialist tools

Cold Cure

Cures at room temperature without hot work

Application Areas

What this product handles, grouped by equipment area — each links to the full application.

Primary application area

Roof Problem Areas

2 applications

Floor Problem Areas

1 application

Roof upstand & protrusion weatherproofingWeatherproofing around upstands and roof protrusionsLearn more

Tanks & Chemical Containment Areas

1 application

Tank base sealingSealing of tank basesLearn more

Technical Data

Coverage & Film Thickness

First Layer DFT (with Belzona 9361 reinforcing sheet): 20 mil (500 micron)
Second Layer DFT: 10 mil (250 micron)
Total System DFT: approximately 30 mil (750 micron)
Conditioner: Use Belzona 3931 on porous surfaces; Belzona 3921 (GSC Surface Conditioner) on glass and metallic surfaces
Reinforcing Sheets: Belzona 9361 for general roof areas; Belzona 9351 where exceptional elasticity is required

Tensile & Elongation Properties (reinforced with Belzona 9361, 7-day cure at 68°F / 20°C)

Tensile Strength: 925 psi (6.4 N/mm²)
Elongation: 190%
Elongation after 3 months QUV accelerated weathering (ASTM G53): typically 125% retained

Tear Strength (ASTM D624, reinforced, 7-day cure at 68°F)

Tear Strength: 195 pli (34.3 N/mm)

Water Vapor Permeability

Reinforced system, BS 2782, 7-day cure at 68°F: 25 g/m² over 24 hours; Impermeable to liquid water but permeable to water vapor (allows roof to breathe)