Fixing and buying guide

What this product is and who it is for

This is a twin and combination flashing system for pitched roof applications. It is designed for use around chimneys, skylights and roof ventilation system openings where a watertight seal is essential. The product suits both professional installers and experienced DIY customers working on residential pitched roof projects. It is not suitable for flat roofs or applications outside the specified timber grades.

Compatibility and sizing

The flashing measures 55 x 98cm and is compatible with timber grades C16 to C32, which covers standard structural softwood used in UK house building. Check your roof timber specification before purchase to ensure compatibility. The dimensions suit standard roof opening sizes; measure your chimney or skylight opening carefully to confirm this flashing will provide adequate coverage around the penetration.

Materials and durability

The flashing features a weather-resistant PVC membrane bonded to durable metal cladding with a corrosion-resistant coating. This combination provides long-term protection against the elements on exposed pitched roofs. The corrosion-resistant metal cladding resists rust and degradation, whilst the PVC membrane prevents water ingress around the roof opening. These materials are designed to withstand UK weather conditions including wind-driven rain and snow loads.

• Weather-resistant PVC membrane prevents water penetration
• Corrosion-resistant metal cladding for durability
• Suitable for exposed pitched roof locations

Pre-installation checks and preparation

Before fitting, inspect your roof opening and surrounding timber to ensure it is sound and free from rot or damage. Confirm the opening dimensions match the flashing size and that your roof pitch is suitable for pitched roof flashing installation. Check that your timber grade is within the C16 to C32 range. Ensure you have appropriate roofing sealant and fixings to hand, and plan the installation to avoid weather delays. If the roof opening is damaged or the timber is not in the specified grades, address these issues before proceeding.

• Verify timber grade is C16 to C32
• Measure roof opening to confirm flashing size is adequate
• Inspect timber around opening for rot or damage
• Gather roofing sealant and fixings before starting work