Fixing and buying guide

Who this is for and what it does

This combi flashing element is for builders, roofers, and experienced DIY installers fitting or replacing VELUX MK08 roof windows on pitched roofs. The integrated design combines the flashing and weatherproofing functions that would otherwise require separate components, making it the complete solution for sealing the window aperture against water ingress and weather exposure.

Compatibility and sizing

This flashing element is designed exclusively for VELUX MK08 roof windows. The 780mm × 1398mm dimensions are fixed to match the MK08 window size, so you must verify your window size before ordering. It is suitable for standard pitched roof pitches and will not fit other VELUX window sizes or flat roof applications.

• Confirm your roof window is MK08 size before purchase
• Designed for pitched roofs only
• Not compatible with other VELUX window sizes

What is included and pre-installation checks

The combi flashing element arrives as a single integrated assembly with both upper and lower flashing components already combined. Before installation, inspect the unit for any damage in transit, ensure your roof aperture dimensions match the MK08 specification, and check that your roof pitch falls within the standard range for pitched roof applications. Have all necessary fixings and sealants to hand, and ensure the roof structure around the aperture is sound and properly prepared.

• Inspect for transit damage upon delivery
• Verify roof aperture matches MK08 dimensions
• Confirm roof pitch is suitable for pitched roof installation
• Prepare roof structure and have fixings ready before starting work

Installation benefits

Using this combi element reduces installation time and complexity by combining flashing and weatherproofing functions into one unit. The integrated design minimises the risk of gaps or misalignment between separate components, helping to guarantee a weathertight seal that protects against water ingress and maintains the thermal performance of your installation.

• Fewer components to fit means faster installation
• Integrated design reduces risk of gaps or leaks
• Ensures consistent weathertight performance