Belzona 4511
Magma-Flex Hi-Build
A two-component elastomeric joint sealant for vertical and horizontal building joints with up to ±12.5% movement.
A two-component, solvent-free, fluid elastomeric sealant for vertical and horizontal building and expansion joints with up to ±12.5% movement. Qualified as ASTM C-719 Class 25, Type M, Grade N.
- SeriesBelzona 4000 Series
- Documents3
Overview of Belzona 4511
Belzona 4511 (Magma Sealant) is a two-component, solvent-free, fluid elastomeric joint sealant designed for vertical and horizontal building and expansion joints with up to ±12.5% movement. Once mixed, the Base and Solidifier form a flexible, low-modulus elastomeric compound suitable for sealing dynamic joints in concrete and other building substrates.
Tested against modified ASTM C-719 "Adhesion and Cohesion of Elastomeric Joint Sealant" and qualified as a Class 25, Type M, Grade N sealant. The cured product delivers 260% elongation, Shore A hardness of 63, and tensile strength of 450–500 psi (31.6–37.7 kg/cm²). Cohesive failure with the sealant in 90° peel adhesion testing on multiple substrates including grit-blasted steel, aluminum, concrete, and Belzona 4111.
Key Benefits
100% solids formulation reduces health and safety risks in confined spaces with no shrinkage on cure
No solvents, no shrinkage during cure
Bonds strongly to virtually any rigid surface
Application Areas
What this product handles, grouped by equipment area — each links to the full application.
Floor Problem Areas
3 applicationsTechnical Data
Composition
- Type
- Two-component, solvent-free, fluid elastomeric joint sealant
- Mixing Ratio by Weight (Base : Solidifier)
- 6.4 : 1
- Mixing Ratio by Volume (Base : Solidifier)
- 5.1 : 1
Components
- Base
- Viscous gray liquid, density 1.22–1.25 g/cm³
- Solidifier
- Clear yellow liquid, density 1.00–1.02 g/cm³
Application
- Working Life at 72°F (22°C)
- 90 minutes
- Volume Capacity
- 204.8 cu.in. (3,354 cm³) per 4.2 kg unit
Tensile Properties (ASTM D412, Die C)
- Tensile Strength
- 450–500 psi (31.6–37.7 kg/cm²)
- Elongation
- 260%
Tear Strength
- ASTM D624
- 77.5 pli (1,384 kg/m)
Hardness
- Shore A (ASTM D2240)
- 63
Adhesion (90° Peel, modified ASTM D429)
- Blasted Steel
- 45.1 pli (805.4 kg/m)*
- Aluminum
- 51.2 pli (914.3 kg/m)*
- Concrete
- 39.7 pli (708.8 kg/m)*
- Belzona 4111 (Magma-Quartz)
- 43.2 pli (771.5 kg/m)*
- * Cohesive failure in Belzona 4511 — sealant fails before bond does
Expansion Joint Application Qualification
- Tested against modified ASTM C-719 "Adhesion and Cohesion of Elastomeric Joint Sealant"
- Qualified as a Class 25, Type M, Grade N sealant (±12.5% movement)
Chemical Resistance
- Excellent resistance to a broad range of chemicals once fully cured
- Refer to Chemical Resistance chart for detailed compatibility information
Shelf Life
- Separate Base and Solidifier components have a 5-year shelf life from date of manufacture in original unopened containers stored between 32°F (0°C) and 86°F (30°C)
Working Life
From commencement of mixing, use within:
- 50°F (10°C)
- 10 hours
- 59°F (15°C)
- 3 hours
- 68°F (20°C)
- 1½ hours
- 77°F (25°C)
- 75 minutes
Curing Time
For approximately ¼ in (6 mm) thickness — reduced for thicker, extended for thinner sections
At 50°F (10°C)
- Light loading
- 20 hours
- Full mechanical or thermal loading
- 2 days
At 72°F (22°C)
- Light loading
- 8 hours
- Full mechanical or thermal loading
- 1 day
At 86°F (30°C)
- Light loading
- 4 hours
- Full mechanical or thermal loading
- 12 hours
At 104°F (40°C)
- Light loading
- 2 hours
- Full mechanical or thermal loading
- 6 hours
At 122°F (50°C)
- Light loading
- 1 hour
- Full mechanical or thermal loading
- 3 hours
Service Temperature Limits
- Working Life at 72°F (22°C)
- 90 minutes — use all mixed material within this time
- Storage Temperature
- 32°F (0°C) to 86°F (30°C) in unopened containers
- Note
- Cure time will be reduced for thicker sections and extended for thinner applications. Consult the IFU for cure schedule details.
Product PDFs
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Frequently Asked Questions
What is Belzona 4511 (Magma-Flex Hi-Build) used for?
Belzona 4511 (Magma-Flex Hi-Build) is a high-build flexible expansion joint sealant designed for vertical and overhead expansion joints in concrete. It accommodates structural movement while providing a durable seal against water, chemicals, and weathering, ideal for bridges, parking decks, and industrial floors.
What is the mixing ratio of Belzona 4511 (Magma-Flex Hi-Build)?
The mixing ratio of the concrete expansion joint filler, Belzona 4511 (Magma-Flex Hi-Build), is 6.4 : 1 (Base : Solidifier) by weight and 5.1 : 1 (Base : Solidifier) by volume. Please see the Product Specification Sheet (PSS) for more information.
How do you apply Belzona 4511 (Magma-Flex Hi-Build)?
To apply the vertical expansion joint sealant, Belzona 4511, the surface must be clean, dry, and firm, free of rust, paint, and other surface coatings and contaminants. Any new concrete must be dry and cured for at least 28 days. Condition the area using Belzona 4911 (Magma TX Conditioner). When mixing entire units, use a mechanical mixer: pre-mix the Base, then slowly add the Solidifier with the mixer running, scraping the bottom and sides for even consistency. Apply Belzona 4511 into the joint avoiding air entrapment, and use a scraper to remove excess material. Allow to cure. Please see the Instructions for Use (IFU) for more information.
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