How and where to use guide
VELUX Twin and Combination Flashings 78x118cm EBL MK06 0021B
Typical applications and installation locations
These twin and combination flashings are used on pitched roofs where two VELUX roof windows are positioned close together, either stacked vertically or arranged side by side. They are suitable for domestic and light commercial pitched roof installations with standard rafter spacing. The flashings work effectively on traditional tiled roofs, natural slate, and sheet-covered pitched roofs. Installation should take place during new roof construction or when replacing existing roof windows, ensuring the flashing sits correctly between the window frame and the roof covering to maintain a weathertight seal.
- Dual window installations on pitched roofs with standard rafter spacing
- Tiled, slated, or sheet-covered roof applications
- New build and replacement roof window projects
- Domestic and light commercial properties
Installation and positioning
The integrated upper and lower flashing components must be positioned so that the upper section sits beneath the roof covering above the window and the lower section sits above the roof covering below the window. The 78x118cm dimensions are designed to align with standard rafter spacing, ensuring the flashing sits flush against the roof structure and window frame. Proper positioning is critical to prevent water ingress at the junction between the window and roof. The flashing should be secured according to VELUX installation guidance, with all joints sealed to maintain weatherproofing integrity.
- Position upper flashing component beneath roof covering above the window
- Position lower flashing component above roof covering below the window
- Align with standard rafter spacing for correct fit
- Ensure all joints and edges are properly sealed
- Follow VELUX installation instructions for securing components
Maintenance and durability
Once installed, these flashings require minimal maintenance. Periodically inspect the flashing seals and joints, particularly after severe weather, to ensure no water ingress has occurred around the window frame. Check that the roof covering remains in good condition around the flashing edges. The integrated design reduces the number of potential leak points compared to separate upper and lower flashings, improving long-term reliability. Any debris accumulation around the flashing should be cleared to maintain proper water drainage.
- Inspect seals and joints after severe weather or annually
- Clear debris from around the flashing to maintain water drainage
- Check roof covering condition at flashing edges
- Integrated design reduces potential leak points
Limitations and compatibility
These flashings are specifically designed for pitched roof installations with standard rafter spacing and are not suitable for flat roofs or non-standard rafter configurations. They are engineered for use with compatible VELUX roof window ranges only. The 78x118cm size is fixed and cannot be adjusted, so accurate measurement of rafter spacing is essential before ordering. Installation should only be undertaken by competent persons familiar with roof work and VELUX window installation procedures. Improper installation may compromise weatherproofing and void product warranties.
- Pitched roofs only; not suitable for flat roof applications
- Standard rafter spacing required; size cannot be adjusted
- Compatible with VELUX roof window ranges only
- Installation by competent persons recommended
- Incorrect installation may compromise weatherproofing