How and where to use guide
VELUX Twin and Combination Flashings 114x118cm EKL SK06 S0122
Typical applications and roof types
These flashings are designed for pitched roof installations where roof windows or other penetrations require weatherproofing. The twin flashing option suits single-pitch roof configurations, whilst the combination flashing provides flexibility for both single- and double-pitch roof designs. The 114×118cm dimensions fit standard roof window openings and typical penetration sizes. Both timber and concrete roof surfaces are compatible with this flashing system, making it suitable for a wide range of pitched roof constructions including slate, tile, and sheet materials.
- Twin flashing: single-pitch roof applications
- Combination flashing: single- and double-pitch roof compatibility
- Suitable for timber and concrete roof surfaces
- Standard size for typical roof window and penetration openings
- Compatible with slate, tile, and sheet roof coverings
Installation and on-site guidance
Install the flashing before laying the final roof covering material to ensure proper water run-off and overlap. Position the flashing around the roof window or penetration, ensuring the upper edge sits beneath the roof covering and the lower edge extends over the covering below. The flashing must be secured firmly to the roof substrate—timber or concrete—according to VELUX installation instructions. Ensure all edges are sealed and overlapped correctly to prevent water penetration at joints. Check that the flashing sits flush against the roof surface with no gaps or lifting.
- Install before final roof covering material is laid
- Position upper edge beneath roof covering, lower edge over covering below
- Secure firmly to timber or concrete substrate
- Seal all edges and joints to prevent water ingress
- Verify flush fit with no gaps or lifting
Weather resistance and durability
The EKL material features corrosion-resistant treatment to withstand harsh weather conditions and extend service life. This treatment protects against rust and degradation from rain, frost, and UV exposure typical of UK pitched roofs. The watertight seal design prevents water ingress during variable weather, including heavy rain and wind-driven precipitation. Regular inspection of the flashing perimeter and roof covering overlap is recommended to maintain performance, particularly after severe weather or seasonal changes.
- Corrosion-resistant EKL material for extended durability
- Engineered watertight seal for variable UK weather conditions
- Resists rust, frost, and UV degradation
- Inspect regularly, especially after severe weather
- Check roof covering overlap and flashing perimeter annually
Limitations and maintenance
This flashing is designed specifically for pitched roof applications and is not suitable for flat roofs. The 114×118cm size is fixed and must match your roof window or penetration opening; verify dimensions before ordering. The flashing relies on correct installation and proper overlap with roof covering materials to function effectively—poor installation will compromise waterproofing. Maintain the flashing by keeping the roof covering and flashing edges clear of debris, moss, and lichen that could trap moisture. Do not attempt to modify or cut the flashing, as this will damage the corrosion-resistant treatment and compromise the watertight seal.
- Pitched roof applications only—not suitable for flat roofs
- Fixed size 114×118cm must match your opening
- Correct installation and roof covering overlap are essential
- Keep flashing edges and roof covering clear of debris and moss
- Do not cut or modify the flashing