Fixing and buying guide

What this product is and who needs it

This recessed flashing is an essential component for installing or re-flashing rooflights and skylights. It creates a watertight seal between the rooflight frame and the roof structure, preventing water ingress around the perimeter of the opening. Use this product if you are fitting a new rooflight, upgrading an existing installation, or carrying out renovation work where the flashing requires replacement or repair.

Compatibility and sizing

The EDN MK08 is compatible with timber roof construction using F16 or F24 grade timber, which covers standard domestic and commercial roof builds. The 78cm × 140cm dimensions suit a range of rooflight and skylight sizes; confirm your rooflight opening matches or exceeds these measurements before ordering. The 8mm thickness provides structural integrity and durability across both new build and renovation applications.

• Check your rooflight opening dimensions are compatible with 78cm × 140cm flashing size
• Verify your roof timber is graded F16 or F24
• Suitable for both domestic and commercial installations

Pre-installation checks

Before fitting, inspect the rooflight opening and surrounding roof structure for damage, rot, or deterioration. Ensure the roof timber is sound and meets the required F16 or F24 grade specification. Check that the opening is square and level, and that any existing flashing is fully removed if this is a replacement installation. Have all necessary fixings and sealants to hand before beginning work.

• Inspect roof timber for damage or rot
• Confirm timber grade is F16 or F24
• Remove any old flashing completely
• Ensure the opening is square and level

Installation and finishing

The recessed design allows the flashing to sit flush with the roof surface, creating a neat appearance whilst maintaining a watertight seal. Follow VELUX installation guidance for your specific rooflight model, ensuring the flashing is correctly positioned and secured to the timber structure. Apply appropriate sealant around the perimeter as recommended by the rooflight manufacturer to complete the weatherproofing.