How and where to use guide
VELUX Standard Flashings 134x140cm EDW UK08 0000
Typical applications and suitability
This flashing is designed specifically for flat roof installations where Velux rooflights up to 134cm wide and 140cm high are being fitted. It is suitable for new-build flat roof construction and retrofit projects in UK buildings. The timber construction makes it appropriate for traditional and modern flat roof systems where the rooflight needs to be sealed against the roof deck. Check that your rooflight dimensions do not exceed 134×140cm; if they do, a larger flashing will be required. This product is not suitable for pitched roof applications or rooflights larger than the specified dimensions.
- Flat roof rooflight installations only
- Rooflights up to maximum 134cm wide × 140cm high
- New-build and retrofit projects
- UK construction applications
Installation and positioning
The flashing must be positioned around the rooflight perimeter before the roof covering is fully sealed. Position the timber flashing so it sits flush against the rooflight frame and extends across the roof deck. The flashing creates the critical weather-tight seal between the rooflight and the roof surface, so it must be installed before waterproofing membranes or roof coverings are applied over it. Ensure the flashing is level and properly supported on the roof deck to prevent movement or gaps. All edges and joints must be sealed according to the rooflight manufacturer's instructions to prevent water ingress at vulnerable points.
- Install before roof covering or waterproofing membrane is applied
- Position flush against rooflight frame on all sides
- Ensure level positioning and full support on roof deck
- Seal all edges and joints to prevent water ingress
- Follow Velux installation guidance for your specific rooflight model
Weather protection and maintenance
Once installed and sealed, the timber flashing works continuously to protect against UK weather conditions including rain, wind, and temperature fluctuations. The weather-tight seal is only effective if the installation is completed correctly and all joints remain sealed. Inspect the rooflight and flashing area periodically, particularly after severe weather, to check that the seal remains intact and there are no signs of water staining or damp around the rooflight frame. If any gaps, cracks, or deterioration appear in the flashing or sealant, repair or reseal immediately to prevent water damage to the roof structure and interior.
- Inspect regularly for signs of water ingress or seal failure
- Check after severe weather or high winds
- Repair or reseal any gaps or damaged sealant promptly
- Maintain clear drainage around the rooflight perimeter
Limitations and on-site tips
This flashing is sized for rooflights up to the specified maximum dimensions; oversized rooflights will require a larger flashing and cannot be safely sealed with this product. The timber material requires careful handling on site to avoid damage, splitting, or warping before installation. Store the flashing in dry conditions and protect it from weather exposure until it is installed and sealed. Do not attempt to cut or modify the flashing dimensions on site, as this will compromise the weather-tight seal. Ensure adequate ventilation around the rooflight installation to prevent condensation issues. Always follow the rooflight manufacturer's complete installation instructions alongside this flashing to guarantee a reliable, durable installation.
- Not suitable for rooflights exceeding 134×140cm dimensions
- Store dry and protected from weather before installation
- Do not cut or modify the flashing
- Handle carefully to avoid damage to timber
- Follow complete Velux installation instructions for your model