How and where to use guide
VELUX Twin and Combination Flashings 55x78cm EKW CK02 S0222
Typical applications and where to install
This flashing is specified for sealing Velux roof vents where they penetrate the roof deck. It is commonly used in flat roof installations and works equally well on pitched roofs where vent positioning allows. The 55×78cm size accommodates standard Velux vent dimensions. Install the flashing at the interface between the vent frame and the roof surface to prevent water pooling and ingress around the vent perimeter. Multiple finish options allow you to select a flashing that blends with your existing roofing material, whether lead, zinc, or other standard roof coverings.
- Flat roof vent sealing applications
- Standard Velux roof vent installations
- Retrofit and new-build vent installations
- Situations requiring watertight seals around vent penetrations
Installation and on-site use
Begin by ensuring the roof surface around the vent opening is clean and free from debris. Position the flashing over the vent frame, utilising the twin design to make fine adjustments before final fixing. The combination feature allows you to accommodate slight variations in vent size or configuration without requiring a different flashing size. Secure the flashing according to the manufacturer's instructions, ensuring all edges are properly sealed to prevent water ingress. The plastic material is durable and resistant to weathering, but take care during handling to avoid damage that could compromise the watertight seal.
- Clean the roof surface and vent frame before installation
- Use the twin design to position and adjust the flashing on site
- Ensure all edges are sealed and secured to prevent water entry
- Follow manufacturer's fixing instructions for your specific roof type
- Check that the flashing sits flush with the roof surface
Maintenance and limitations
Once installed, the flashing requires minimal maintenance. Periodically inspect the seal around the vent perimeter, particularly after severe weather, to ensure no water ingress has occurred. Clear any debris or moss growth that may accumulate around the flashing edge. The plastic material is durable but should not be subjected to impact damage or excessive foot traffic. This flashing is designed specifically for Velux roof vents; do not use with incompatible vent systems. Ensure the timber grade of your roof structure meets FSC 118 or equivalent specifications for proper compatibility and performance.
- Inspect the seal periodically for signs of water ingress or damage
- Clear debris and moss growth from around the flashing
- Avoid impact damage or unnecessary foot traffic over the flashing
- Use only with Velux roof vents of compatible dimensions
- Verify roof timber grade compatibility before installation