Mesh Method for Lightning Protection
Protecting your property from lightning is crucial, especially in countries like Malaysia, where lightning strikes are frequent. The Mesh Method for Lightning Protection uses a network of wires on the roof to safely spread lightning energy, preventing damage. This method is commonly used for large buildings and factories, providing reliable protection.
In this blog, we will try to understand deeply how the Mesh Method helps in lightning protection and why it’s an effective solution for safeguarding your property.
What is the Mesh Method for Lightning Protection?
The Mesh Method for Lightning Protection is a systematic approach designed to safeguard structures from lightning strikes by employing a network of conductors. This method, defined by the international standard IEC 62305, creates a protective mesh over flat surfaces, ensuring that lightning currents are effectively directed to the ground.
- Definition and Concept: The Mesh Method involves placing conductors in a grid pattern across the structure’s surface, where the spacing between conductors is determined by the level of protection required, based on a risk assessment.
- Historical Background: Over time, the Mesh Method has evolved alongside advancements in lightning protection technology and standards, becoming one of three primary design methods recognized in contemporary engineering practices.
- Mechanism: In practical scenarios, the mesh provides multiple paths for lightning to travel to the ground, minimizing the risk of damage. Conductors are strategically positioned at roof edges and overhangs, ensuring that all areas are covered and that no metal protrudes beyond the protected volume.
“This method is particularly advantageous for flat-roofed structures, and can also be adapted for vertical surfaces to enhance protection against side flashes”
Key components of the Mesh Method for Lightning Protection
The key components of the Mesh Method for Lightning Protection are vital for capturing, transmitting, and safely dissipating lightning strikes. These components include:
| Component | Description |
| Air Termination Network | Lightning Rods: Placed on the roof to intercept lightning strikes.Strike Pads: Extra points of interception for broader protection. |
| Down Conductor Network | Conductors: Pathways that carry the lightning current from the roof to the ground.Fixings: Secure the conductors to prevent movement. |
| Earth Termination System | Ground Rods: Installed in the ground to safely dissipate electrical energy.Earth Mats: Expanded grounding system for improved energy discharge. |
Together, these components create a reliable and effective lightning protection system, ensuring the safety and integrity of the building.
Understanding Mesh Size and Its Impact on the Mesh Method for Lightning Protection
Definition of Mesh Size: What it Means and Its Relevance
In lightning protection, mesh size is the spacing of the conductor grid that intercepts and redirects lightning strikes safely to the ground, reducing structural damage. The IEC/BS EN 62305 standard defines four mesh sizes based on the Lightning Protection System (LPS) class:
| LPS Class | Mesh Size |
| Class I | 5 x 5 meters |
| Class II | 10 x 10 meters |
| Class III | 15 x 15 meters |
| Class IV | 20 x 20 meters |
Impact on Protection: How Mesh Size Affects the Mesh Method
The effectiveness of the mesh method for lightning protection depends on the mesh size. Smaller grids, like Class I (5 x 5 meters), offer higher protection and are ideal for high-risk buildings, such as hospitals or flammable storage. Larger mesh sizes provide sufficient protection for lower-risk structures.
Optimal Mesh Sizes for Different Structures
Choosing the right mesh size depends on the building’s risk level:
| Structure Type | Recommended Class and Mesh Size |
|---|---|
| High-risk structures (e.g., hospitals) | Class I (5 x 5 meters) |
| Standard buildings | Class II or III (10 x 10 or 15 x 15 meters) |
| Low-risk structures | Class IV (20 x 20 meters) |
Using appropriate mesh sizes ensures effective lightning protection while controlling costs.
Design Requirements for the Mesh Method in Lightning Protection
- Risk Assessment: In the Mesh Method for Lightning Protection, assess lightning risks by evaluating building height, location, materials, and surroundings.
- Air Termination Placement: Place air termination conductors along roof edges, overhangs, and ridges to intercept lightning strikes, especially near the outer edges on flat roofs.
- Conductor Spacing: Ensure air rods are spaced no more than 10 meters apart, and strike plates no more than 5 meters, to provide thorough coverage.
- Mesh Size and Layout: Determine the appropriate mesh size based on the risk assessment and arrange conductors effectively across the structure.
- Down Conductors: Position down conductors along building corners to safely direct lightning currents to the ground.
- Equipotential Bonding: Connect all major metal parts to a common grounding point to prevent sparking during lightning strikes.
- Placement of Air Terminals and Down Conductors: Position air terminals in high-risk areas, avoiding issues like improper spacing, which can compromise protection.
Following these guidelines ensures buildings have effective lightning protection using the Mesh Method.
Materials Requirements for the Mesh Method for Lightning Protection
In order to effectively implement the Mesh Method of Lightning Protection, it’s crucial to use the recommended materials to ensure safety and efficiency. Below are the materials commonly used in this system:
Recommended Materials
| Item | Code | Table |
| Franklin air rod | AT-008A | 5 |
| Franklin air rod base | AT-116B | 17 |
| Self-supporting air rod | AT-104A | 10 |
| Expansion unit | AT-012G | 108 |
| Roof conductor holder | AT-041E | 66 |
| Clamp | AT-039F | 88 |
| Conductor | AT-057D | 123 |
Additional Materials
| Item | Code | Table |
| Clip | AT-240E | 46 |
| Rainwater pipe bond | AT-025J | 87 |
| Clamp | AT-039F | 88 |
| Bimetallic connector | AT-094F | 103 |
| Guard tube | AT-060G | 107 |
| Joint protection | AT-060G | 107 |
| Conductor | AT-057D | 123 |
Installation Guidelines for the Mesh Method for Lightning Protection
- Air termination should be placed on roof edges, overhangs, and ridge lines with a pitch greater than 5.7°.
- No metal structures should extend beyond the protected area.
- The network must have at least two direct paths to the earth electrodes, following the shortest route to the ground.
“Roof corners and edges are most vulnerable to lightning. Place conductors close to these areas for better protection”
Key Specifications and Features of the Mesh Method for Lightning Protection
- Mesh Conductor Systems: A grid-like network intercepts lightning and channels it safely to the ground.
- Design and Configuration: Custom-built to fit the roof’s geometry, ensuring complete coverage.
- Protection Levels: Conductor spacing adjusted by protection level:
- Level I: 5 meters
- Level II: 10 meters
- Level III: 15 meters
- Level IV: 20 meters
- Material and Durability: Selected for longevity, particularly in harsh environments.
- Aesthetic Compatibility: Designed to complement the building’s architecture.
- Structural Integration: Incorporated into the building design from the beginning.
- Uniform Energy Dissipation: Distributes lightning energy evenly across the network.
- Design Flexibility: Adaptable to complex roof structures.
These specifications highlight the essentials of the Mesh Method for lightning protection effectiveness.
Maintenance and Testing of the Mesh Method for Lightning Protection
The mesh method for lightning protection places a conductor mesh on structures to shield them from strikes. Key maintenance considerations include:
- Visual Inspection: Annually or semi-annually in severe weather areas. Check for damage, corrosion, or wear.
- Earth Resistance Testing: Conduct tests during major temperature and humidity shifts.
- Complete Inspection: Every 3–5 years, or every 1–3 years for critical systems.
- Electrical Testing (Explosive Assets): Every 17 months.
- Surge Protection Inspection (Explosive Assets): Every 7 months.
- Soil Resistivity & Grounding Testing: Measure soil resistivity and grounding resistance regularly.
The mesh method works well on flat surfaces, but is unsuitable for curved areas.
Grounding and Bonding Requirements for the Mesh Method for Lightning Protection
- Grounding and Bonding: These are essential for ensuring effective lightning protection.
- Grounding: Involves creating a low-impedance path to safely dissipate the energy from a lightning strike into the earth.
- Bonding: Connects all metallic parts and conductors to maintain the same electrical potential, preventing dangerous voltage differences.
- Components to Bond:
- Grounded media
- Buried metallic conductors
- Structural elements
- Purpose: Ensures the reliability and safety of the lightning protection system.
- Benefits: Minimizes the risk of arcing and internal sparking by maintaining equipotential bonding.
By following these grounding and bonding requirements, the Mesh Method for Lightning Protection ensures that structures are effectively shielded from the dangers of lightning strikes.
Durability and Longevity of the Mesh Method for Lightning Protection
The durability and longevity of the Mesh Method for Lightning Protection depend on several factors:
- Material Quality: Using high-quality, corrosion-resistant materials ensures the system withstands harsh weather conditions and environmental exposure.
- Proper Installation: Correct installation by trained professionals is crucial for the system’s long-term performance.
- Regular Maintenance: Periodic inspections and maintenance help identify and address any potential issues, extending the system’s lifespan.
- Environmental Conditions: The system’s durability can be affected by factors like humidity, salt exposure, and temperature fluctuations.
By considering these factors, the Mesh Method can provide reliable and long-lasting lightning protection for buildings.
Risk Mitigation Strategies using the Mesh Method for Lightning Protection
- Conductor Placement: To mitigate risk, ensure conductors are placed at roof edges, overhangs, and ridges to intercept lightning strikes effectively.
- Proper Spacing: Maintain appropriate spacing between conductors based on the desired protection level to ensure comprehensive coverage.
- Regular Inspections: Conduct periodic inspections and maintenance to identify and address potential issues promptly.
- Quality Materials: Use high-quality, corrosion-resistant materials to enhance the system’s durability and longevity.
- Equipotential Bonding: Bond all metallic parts and conductors to prevent dangerous voltage differences and minimize the risk of internal sparking.
These strategies help to ensure effective lightning protection and enhance the safety of structures.
Comparing the Mesh Method for Lightning Protection to Other Methods
| Aspect | Rolling Sphere Method | Protection Angle Method | Mesh Method for Lightning Protection |
| Concept | Theoretical sphere for unprotected areas. | Protective angle to form a cone. | Grid of conductors to intercept strikes. |
| Application | Complex structures. | Simple structures. | Flat or slightly inclined roofs. |
| Installation | Air terminals along sphere path. | Terminals based on angle. | Conductors placed in grid. |
| Protection Level | Varies with sphere radius. | Based on angle and height. | Depends on conductor spacing. |
| Flexibility | Flexible for complex shapes. | Less flexible. | Less flexible for curves. |
The Mesh Method for Lightning Protection is best for flat roofs, offering reliable coverage. While the Rolling Sphere and Protection Angle Methods suit complex or simple structures, the Mesh Method is often the most effective choice for standard applications. All methods comply with IEC 62305 standards, ensuring reliable protection.
Applications of the Mesh Method for Lightning Protection
Ideal Structures for the Mesh Method for Lightning Protection
The Mesh Method is particularly well-suited for structures with the following characteristics:
- Flat or slightly inclined roofs: The mesh can be easily installed and provides uniform coverage.
- Large, open areas: Such as sports arenas, warehouses, and industrial buildings.
- Complex roof geometries: The mesh can be customized to fit intricate designs.
- Buildings with metal roofs: The mesh can be integrated seamlessly.
Case Studies: Real-World Examples
- Sports Arena in Florida: A mesh conductor system was installed over the roof of a sports arena to protect against lightning strikes. The system provided extensive coverage and ensured that lightning energy was uniformly dissipated, preventing localized damage1.
- Industrial Warehouse in Germany: A large industrial warehouse implemented a mesh protection system to safeguard its extensive roof area. The system was designed to blend with the building’s architecture while providing robust protection1.
Examples of Implementations and Success Stories
- ERICO Lightning Protection Handbook: This handbook provides practical advice and examples of mesh protection systems implemented globally. It highlights the importance of proper design and installation to ensure effective lightning protection2.
- ElectroTechnik Case Study: A building in Germany was enclosed in a metallic mesh, creating a Faraday cage effect. This ensured that lightning strikes were safely directed to the ground, protecting the building from damage3.
These examples demonstrate the versatility and effectiveness of the Mesh Method for Lightning Protection in various real-world scenarios.
Benefits of the Mesh Method for Lightning Protection
The mesh method for lightning protection provides several advantages, especially for buildings with complex designs.
- Enhanced Coverage and Protection: The grid layout of the mesh method for lightning protection offers widespread, even coverage, capturing and safely redirecting lightning strikes no matter where they hit the roof.
- Aesthetic Compatibility: The mesh method for lightning protection can be customized to match the building’s architecture, ensuring effective protection without affecting its appearance.
- Structural Integration: This method can be incorporated into the building’s design from the start, creating a unified and discreet lightning protection solution.
Why Choose TAKO’s Mesh Method for Lightning Protection?
1. Expertise and Local Experience
With over 21 years in lightning protection, TAKO understands Malaysia’s unique lightning risks, making its Mesh Method for Lightning Protection highly effective.
2. Certified Safety Standards
TAKO’s Mesh Method for Lightning Protection meets MS IEC 62305 standards, covering risk assessment, design, and maintenance to ensure reliable protection.
3. Full Service and Free Site Visit
TAKO offers a full service from site assessment to installation, plus a free site visit worth RM380 to help clients understand their lightning protection needs.
4. Custom Solutions for Cost Efficiency
TAKO customizes each system to the building, delivering cost-effective, optimized protection. If you want to learn more about TAKO, you can visit our website: www.TakoLightningSystem.com
FAQs
Which mesh method is best?
The best mesh method for lightning protection depends on the building’s size, design, and risk level. Typically, smaller mesh sizes provide better coverage and higher protection.
What is mesh protection?
Mesh protection is a lightning protection method that uses a network of conductors placed on a building’s roof to intercept and safely direct lightning strikes to the ground.
Why is a mesh system better?
A mesh system offers better coverage, aesthetic compatibility, and can be integrated seamlessly into a building’s design, making it an effective lightning protection choice for complex structures.
How many types of lightning protection are there?
There are several types of lightning protection systems, including the mesh method, Franklin rods, catenary wires, and early streamer emission (ESE) systems.
Disclaimer
The information contained in this blog is for informational and marketing purposes only and should not be taken as professional advice. Our focus is on providing comprehensive LPS total solution services. This service encompasses a wide range of solutions to design, install, and maintain a complete lightning protection system tailored to your specific needs. For any questions or to discuss your specific lightning protection needs, please contact us directly.
