“Breeze block” (UK/AU) and “screen block” (U.S.) refer to the same product type. In breeze blocks vs screen blocks comparisons, the distinction is terminology rather than form. Jonite’s version is engineered reinforced stone, not standard concrete, tested per ASTM C140 methods for compressive strength and carrying a Class 1 fire rating under BS 476 Part 7 (UK/international standard; ASTM E84 testing in progress for U.S. code alignment).
Key Takeaways
• “Breeze block” = “screen block” in U.S. specification documents
• Jonite products are engineered reinforced stone, not standard CMU
• Tested per ASTM C140 methods for compressive strength
• Class 1 fire rating under BS 476 Part 7 (UK/international standard; ASTM E84 testing in progress for U.S. code alignment)
• Contains ≥30% recycled content and may contribute to LEED (USGBC MR Credit 4)
• Free-standing walls: up to 2m height without additional structural support
What’s the difference between a breeze block and a screen block?
There is no material difference. “Breeze block” is the informal term commonly used in the UK and Australia, while “screen block” or architectural screen block specification terminology is used in U.S. project documents. Both refer to modular, patterned masonry units used for ventilation, screening, and façade design.
In U.S. project documentation, using “breeze block” instead of “screen block” can lead to confusion during procurement, particularly when contractors or suppliers default to standard concrete CMU products. Clear terminology helps ensure the specified material, pattern, and performance requirements are correctly understood.
That said, terminology is only part of the decision. For most U.S. architects, the more important distinction is material performance, particularly when comparing standard concrete screen blocks with engineered alternatives.
What makes Jonite breeze blocks different from standard concrete screen blocks?
The primary difference is material. Standard screen blocks are made from Portland cement concrete, while Jonite breeze blocks are made from engineered stone composed of at least 95% natural aggregates with a small percentage of hybrid polymers.
Concrete screen blocks rely on cement binders and typically contain higher silica content. Jonite’s composite replaces this with a denser stone matrix, resulting in a product with less than 1% silica and improved resistance to environmental exposure. The material is non-corrosive and does not rust, with consistent performance in conditions where moisture, salt, or temperature variation would degrade traditional concrete over time.
The material is heat-resistant, non-corrosive, and slip-resistant, with consistent performance in exposed environments.
From a sustainability perspective, Jonite breeze blocks contain at least 30% recycled content and are manufactured with reduced reliance on cement-based materials. This contributes to lower embodied impact compared to standard concrete alternatives, depending on project requirements.
Are Jonite breeze blocks certified for U.S. commercial projects?
Yes. Jonite breeze blocks are tested to ASTM C140/C140M-24a for compressive strength, making them suitable where an ASTM-tested breeze block wall is required in U.S. commercial specifications. They are also tested to a Class 1 fire rating under BS 476 Part 7.
Additional testing includes ASTM B117 (salt spray) and SS245:1995 (water absorption). For most U.S. specifiers, load classification and fire rating are the primary decision gates, allowing Jonite systems to be assessed alongside conventional screen block options.
Which Jonite breeze block pattern is right for your project?
The key specification variable is open-area percentage. Higher open-area blocks increase airflow and light penetration, while lower percentages provide greater privacy and visual screening. For architects specifying breeze blocks in the USA, this becomes a performance decision as much as a design one, particularly in climates where airflow and solar control are critical. Pattern selection is not only aesthetic. It directly affects ventilation, shading, and how the wall performs within the space.
Jonite breeze blocks have been used across residential and hospitality projects globally, including facade and ventilation applications in tropical and urban environments.
• Modubloc offers the widest range, from QUAD-200 at 56% open for ventilation-focused applications to BEV-200 at 18% open for privacy. This makes it suitable for residential boundaries, parking structures, and mixed-use screening where requirements vary.
• Vista (VIST-250, 54% open) features a structured A-frame geometry, often used in hospitality facades and feature walls, where airflow and visual rhythm are both priorities.
• Prism (PRIS-250, 64% open) provides the highest airflow, making it suited to courtyard screens, plant enclosures, and solar shading applications in warmer climates.
• Tessera ranges from 43% to 17% open, offering more controlled screening. It is commonly specified for interior partitions, transitional spaces, and areas requiring a balance of light and privacy.
• Molecules range from 16% to 33% open, with an organic circular pattern. It is often used in residential settings, pool surrounds, and landscape applications where a softer visual language is preferred.
What do U.S. architects need to know before specifying a breeze block wall?
Specification should be treated as a structural decision, not just a design feature. Wall type, height, and support conditions determine how breeze blocks perform in use. This differs from standard approaches to decorative concrete block specifications in the US, where material behaviour may vary.
Jonite provides defined installation parameters, but projects exceeding these limits should involve a structural engineer.
For façade applications above 2m, additional structural support such as a steel frame is required. Walls beyond these limits should be reviewed by a structural engineer.
For reinforced installations, #2 or #3 rebar is recommended, with consistent mortar joint spacing of 6–10mm.
Can Jonite breeze blocks be customised for non-standard projects?
Yes. Jonite breeze blocks can be customised to suit non-standard architectural requirements, including bespoke geometries, performance targets, and design intent.
Customisation options include colour and texture matching, pattern modifications, open-area adjustment, and size or curve specifications. For projects that fall outside standard formats, fully bespoke designs can be developed from the ground up to meet both visual and technical requirements.
Projects are delivered through a structured five-step process: Collaboration, Conceptualisation, Design & Testing, Approval, and Production. This allows design teams to explore custom ideas while maintaining control over performance, constructability, and lead times.
How do I specify Jonite breeze blocks for a U.S. project?
Specification typically follows a clear sequence, moving from design intent through to technical validation and procurement.
1. Select the appropriate collection and open-area percentage based on ventilation, privacy, and shading requirements.
2. Confirm wall type and structural classification with a structural engineer, particularly for facades or walls exceeding standard height limits.
3. Reference ASTM C140 in the specification to establish compressive strength and structural performance criteria.
4. Request samples and technical documentation from Jonite to validate material, finish, and detailing.
5. Confirm lead times and project requirements through a B2B or trade enquiry.
For full product details, explore Jonite breeze blocks or contact our USA team to begin the specification process.
FAQs
Are breeze blocks and screen blocks the same thing?
Yes. “Breeze block” is the informal term used in the UK and Australia, while “screen block” or “architectural screen block” is the formal term used in U.S. specification documents. Both refer to patterned masonry units used for ventilation, screening, and facade design. In U.S. projects, using “screen block” helps avoid confusion during procurement and ensures alignment with industry terminology.
Are Jonite breeze blocks suitable for U.S. commercial projects?
Yes. Jonite breeze blocks are suitable for U.S. commercial projects when specified within structural and code requirements. They are tested per ASTM C140 for compressive strength and structural load, with a Class 1 fire rating (BS 476 Part 7), which addresses two key decision gates for commercial specification.
Additional testing includes ASTM B117 for corrosion resistance and SS245:1995 for water absorption, supporting use in exposed environments. As with any screen block system, wall type, height, and support conditions should be reviewed by the project team, with input from the structural engineer required for applications that exceed standard parameters.
What ASTM standards apply to Jonite breeze blocks?
ASTM C140/C140M-24a is the test method applied to Jonite breeze blocks, covering compressive strength and water absorption for masonry units. This is the primary ASTM standard referenced in U.S. specifications.
For environmental durability, ASTM B117 may also be referenced for salt spray resistance in exposed conditions. These standards are typically reviewed alongside project-specific structural and performance requirements during specification.
Are Jonite breeze blocks fire rated?
Yes. Jonite breeze blocks are tested to a Class 1 fire rating under BS 476 Part 7, making them suitable for projects requiring fire-rated breeze blocks that architects can specify with confidence.
For U.S. projects, fire requirements should be reviewed against local codes, with documentation available as part of the specification process.
What is the maximum height for a Jonite breeze block wall without a structural engineer?
Up to 2 m. Jonite recommends a maximum height of 2 m for breeze block walls without additional structural support.
Free-standing walls within this limit can be installed using standard parameters, including control joints at 2 m intervals. For walls exceeding 2 m in height, or for facade and suspended applications, a structural engineer should be consulted to confirm support requirements and compliance with local building codes.
Can Jonite breeze blocks contribute to LEED certification?
Yes. Jonite breeze blocks contain at least 30% recycled content and are produced by a USGBC member, which may contribute toward LEED credits such as MR Credit 4 (Recycled Content), depending on project requirements.
Contribution is assessed at the project level, so eligibility should be confirmed within the broader material schedule and LEED strategy.
