Code 5 Lead Flashing

What is Code 5 Lead Flashing? 

Code 5 lead flashing is a type of roofing and construction material specifically designed to prevent water infiltration at junctions and joints where different surfaces meet, such as between a roof and a wall, around chimneys, or at roof valleys. The "Code" system used to categorise lead flashing refers to its thickness, with higher numbers indicating thicker sheets. In the case of Code 5, the lead has a thickness of 2.24mm.

This thickness strikes a balance between flexibility and strength, making Code 5 lead flashing versatile and suitable for a wide range of applications. It can be easily shaped and moulded to fit the specific contours of a building’s structure, ensuring a secure and effective seal. Lead flashing is commonly used in areas of high vulnerability to water penetration, such as roof penetrations, chimney stacks, dormers, skylights, and valleys.

Applications

• Protecting chimneys
• Sealing roof valleys
• Waterproofing dormer windows
• Reinforcing parapet walls
• Securing roof-to-wall junctions
• Covering flat roof edges

Benefits

• Long Lifespan: Lead flashing is one of the most durable roofing materials, often lasting over a century with minimal maintenance. It withstands environmental wear and tear far better than alternatives like aluminium or zinc, reducing the need for frequent replacements.
• Weather Resistance: Designed to endure harsh weather conditions, lead flashing remains stable under extreme temperatures, heavy rainfall, and frost, preventing water ingress and structural damage.
• Flexibility: Despite its strength, lead is highly malleable, allowing it to be shaped and fitted into intricate roofing details without cracking or breaking. This makes it ideal for complex architectural designs.
• Corrosion Protection: Unlike steel or iron, lead does not rust, making it an excellent long-term solution for moisture-prone areas. It naturally forms a protective patina that further enhances its resistance to corrosion.
  
  

Installation Considerations

• Support & Fixings: Support is essential to prevent lead from sagging or distorting over time. Secure it using corrosion-resistant fixings such as stainless steel to ensure long-lasting performance.
• Expansion Gaps: Lead expands and contracts with temperature changes. To prevent cracking or warping, allow for thermal movement by incorporating adequate expansion gaps and securing joints with sealant or welding where necessary.
• Patination Oil: Applying patination oil after installation helps prevent lead carbonate staining (a white residue that forms due to weather exposure). This treatment preserves the flashing’s appearance and enhances its resistance to the elements.
• Safety Precautions: Handling lead requires protective measures. Always wear gloves to prevent skin contact, avoid inhaling lead dust or particles, and follow hygiene guidelines, such as washing hands after work, to minimise health risks.