Belzona 3211
Lagseal
A single-component, seamless and flexible coating for encapsulation of all types of thermal insulation and cladding systems.
A water-based acrylic emulsion membrane providing seamless flexible protection of thermal insulation and cladding systems.
- SeriesBelzona 3000 Series
- Approvals1
- Documents4
Overview of Belzona 3211
A water-based acrylic emulsion membrane incorporating a polymer bonded glass reinforcing sheet (Belzona 9321) designed to provide seamless, flexible protection to all types of thermal insulation and cladding systems.
Belzona 3211 (Lagseal) is water, weather and fire resistant, and conforms to the requirements for a 'Class O' surface for 'The UK Building Regulations 1991' and 'Class A' in accordance with 'ASTM E84'. The system provides protection from water ingress whilst its microporous nature allows trapped moisture from within the insulation to evaporate. This 100% solids, single pack system requires no mixing and is simple to apply to damp as well as dry insulation.
Key Benefits
Conforms to Class O surface UK Building Regulations and Class A ASTM E84 fire resistance
Easy to mix and apply without specialist tools
No solvents, no shrinkage during cure
Cures at room temperature without hot work
Will not support growth of bacteria or algae providing a hygienic finish
Excellent oil resistance for industrial environments
Allows trapped moisture to escape while providing long-term weatherproofing protection
Bonds strongly to virtually any rigid surface
Application Areas
What this product handles, grouped by equipment area — each links to the full application.
Tanks & Chemical Containment Areas
2 applicationsTechnical Data
Coverage & Drying
- First Coat DFT (with reinforcement sheet)
- 10 mil (250 micron)
- Second Coat DFT
- 6.0 mil (150 micron)
- Drying Time
- Water resistant within 60 minutes under good drying conditions
- Application Limits
- Do not apply when relative humidity above 90% or surface temperature below 41°F (5°C)
Tensile & Elongation Properties (7-day cure at 68°F / 20°C, ASTM D412)
- Tensile Strength Unreinforced
- 328 psi (2.3 N/mm²)
- Tensile Strength Reinforced Crosswise
- 5,275 psi (36.4 N/mm²)
- Tensile Strength Reinforced Lengthwise
- 3,900 psi (26.9 N/mm²)
- Elongation Unreinforced
- 40%
- Elongation Reinforced Crosswise
- 2.4%
- Elongation Reinforced Lengthwise
- 1.2%
Tear Strength (ASTM D624)
- Unreinforced
- 95 pli (17 N/mm)
- Reinforced Crosswise
- 305 pli (53 N/mm)
- Reinforced Lengthwise
- 183 pli (32 N/mm)
Water Vapor Properties (ASTM E-96, 7-day cure at 68°F)
- Water Vapor Transmission Unreinforced
- 125.3 g/m² over 24 hours
- Water Vapor Transmission Reinforced
- 99.0 g/m² over 24 hours
- Permeance Unreinforced
- 10.5 Perms
- Permeance Reinforced
- 8.6 Perms
Weathering & UV
- After 1,000 hours ISO 11341 UV exposure, retains significant tensile and tear strength performance
- No significant chalking or color change after 8,500 hours ISO 4892-2 (Xenon Arc) exposure
Fire Resistance
- Classification of C s2 d0 per EN 13501-1 (tested per ISO 11925-2 SFI and EN 13823 SBI)
- Class O surface per UK Building Regulations 1991
- Class A per ASTM E84
Service Temperature Limits
- Minimum application temperature
- 41°F (5°C)
- Maximum service temperature (typical)
- 212°F (100°C) for many applications
- Maximum relative humidity for application
- 90%
Mixing & Application
Certifications & Approvals
Product PDFs
Gallery
Related Products
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