How and where to use guide
VELUX Twin and Combination Flashings 66x118cm EKW FK06 0021E
Suitable applications and roof types
This twin flashing is compatible with most common UK roofing materials, including interlocking slate, corrugated metal sheets, concrete and clay pantiles, and thatched roofs. It accommodates roof pitches ranging from 15° to 90°, making it suitable for shallow-pitch commercial roofs through to steep domestic pitches. The flashing works with flat or profiled roofing materials where the profile height does not exceed 120mm, which covers standard domestic and light commercial applications.
- Interlocking slate and natural slate roofs
- Corrugated metal and fibre cement sheets
- Concrete and clay pantiles
- Thatched roofs
- Roof pitches from 15° to 90°
- Profiled roofing up to 120mm profile height
Installation and positioning
The twin flashing is engineered specifically for VELUX roof windows with a 100mm frame spacing between the two units. Position the windows precisely 100mm apart before installing the flashing to ensure a proper fit and weathertight seal. The dark grey lacquered aluminium construction is pre-formed to couple the two window frames, simplifying the installation process compared to installing two separate flashings. Ensure the roof structure is prepared correctly and that both window frames are level and securely fixed before fitting the coupling flashing.
- Position VELUX windows exactly 100mm apart
- Ensure both window frames are level and secure
- Install flashing to create weathertight seal between windows
- Follow VELUX installation instructions for your specific roof type
- Check roof pitch is within 15° to 90° range before installation
Maintenance and durability
The dark grey lacquered aluminium finish provides excellent durability and weather resistance. Inspect the flashing periodically, particularly after severe weather, to ensure the seal remains intact and no debris has accumulated around the window frames. The aluminium construction resists corrosion, but ensure guttering and roof drainage systems function correctly to prevent water pooling around the flashing. Clean the flashing and window frames of moss, lichen and debris to maintain long-term performance.
- Inspect flashing seal annually and after severe weather
- Clear debris and moss from around window frames
- Ensure roof drainage systems function properly
- Do not allow water to pool around the flashing
- Lacquered aluminium requires no special treatment
Limitations and important considerations
This flashing is designed exclusively for two VELUX roof windows with 100mm spacing; it cannot be used for single windows or alternative spacing widths. The maximum roofing profile height of 120mm means it is not suitable for deep-profile metal decking or standing seam systems. Verify your roof pitch falls within the 15° to 90° range, as installations outside this range may compromise weathertightness. Always confirm window size compatibility (66 × 118cm) before ordering.
- Designed only for two windows with 100mm spacing
- Not suitable for roofing profiles exceeding 120mm height
- Roof pitch must be between 15° and 90°
- Confirm window size is 66 × 118cm before installation
- Cannot be adapted for alternative window configurations