How and where to use guide
VELUX Twin and Combination Flashings 55x98cm EKL CK04 S0312
Where to use these flashings
These twin and combination flashings are primarily used on pitched roofs where roof windows, pipes, or other penetrations break through the roof surface. The 55x98cm dimensions are designed to fit standard VELUX roof window installations and similar sized penetrations. They work effectively on roofs with complex angles and curves, making them ideal for properties with varied roof pitches or multiple penetration points. The flashings suit both traditional timber-framed roof structures and modern concrete roof systems, giving them broad application across residential and light commercial pitched roof projects.
- Roof window installations and similar sized penetrations
- Pitched roofs with angles between 15 and 90 degrees
- Timber-framed and concrete roof structures
- Properties requiring watertight seals against wind-driven rain and snow
Installation and positioning
Position the flashing so that the upper edge sits under the roof covering above the penetration, and the lower edge sits over the roof covering below. This overlapping arrangement ensures water runs down and away from the penetration rather than pooling or running back underneath. The flashing must be secured firmly to the roof structure and sealed at all edges. Ensure the flashing sits flush against the roof surface to eliminate gaps where water could enter. On complex roof angles, the combination flashing design accommodates the varied pitch, reducing the need for additional cutting or adaptation on site.
- Install upper edge under roof covering, lower edge over roof covering
- Secure flashing firmly to roof structure with appropriate fixings
- Seal all edges to prevent water ingress
- Ensure flush contact with roof surface across the entire flashing
Weather protection and durability
The high-quality metal construction with durable weather-resistant coating provides long-term protection against the elements. The flashing is engineered to withstand wind-driven rain and snow, common challenges on UK pitched roofs. The metal finish resists corrosion and maintains its integrity through seasonal temperature changes and exposure to moisture. Regular inspection of the flashing and surrounding roof area after severe weather is recommended to ensure the seal remains intact and no debris has accumulated that might compromise water drainage.
- Durable metal finish resists corrosion and weather damage
- Withstands wind-driven rain and snow penetration
- Maintains integrity through temperature fluctuations
- Inspect regularly, especially after severe weather
Maintenance and on-site tips
Keep the flashing and surrounding roof area clear of debris, moss, and leaves that could block water drainage. Check that the seal around the flashing edges remains intact and has not cracked or separated. If the flashing is damaged or the seal fails, water can quickly penetrate into the roof structure, so prompt repair or replacement is essential. When working at height on pitched roofs, use appropriate safety equipment and scaffolding. The 55x98cm size is manageable for two-person handling, but ensure secure footing and support when positioning the flashing on the roof.
- Clear debris and leaves from flashing and surrounding roof area
- Check seal integrity regularly for cracks or separation
- Replace promptly if damaged to prevent water ingress
- Use appropriate safety equipment when working at height