How and where to use guide
VELUX Twin and Combination Flashings 134x98cm EKL UK04 0021E
Where to use this flashing
This flashing is specifically designed for VELUX rooflight installations in pitched roof applications. It creates the weathertight interface between the rooflight frame and the surrounding roof structure. The flashing suits timber roof constructions using structural grades F16, F24 or F36, which covers most domestic and light commercial roof framing. It is suitable for roof pitches up to 30 degrees; steeper pitches or other roof types may require alternative flashing solutions.
- Domestic pitched roof installations with VELUX rooflights
- Timber-framed roofs with grades F16, F24 or F36
- Roof pitches between approximately 15 and 30 degrees
- New rooflight installations or replacement of existing units
Installation and application
The flashing must be installed as part of the rooflight frame assembly, positioned to direct water away from the rooflight opening and into the surrounding roof covering. The 134×98cm dimensions are sized to accommodate standard rooflight openings. Installation should follow VELUX guidance for your specific rooflight model, ensuring the flashing sits correctly under roof tiles or slates and above the rooflight frame. The plastic construction allows for careful handling and positioning during installation. Ensure all edges are properly sealed and secured to prevent water penetration at the interface between the flashing and roof covering.
- Position flashing to overlap roof covering above the rooflight
- Ensure flashing sits correctly under tiles or slates
- Secure flashing according to VELUX installation instructions
- Check for proper water run-off direction before completing roof covering
- Avoid forcing or bending the flashing excessively during installation
Limitations and maintenance
This flashing is designed for roof pitches up to 30 degrees; installations on steeper pitches require alternative products. The plastic construction is durable but should be protected from damage during installation and subsequent roof work. Once installed and covered by roof tiles or slates, the flashing requires minimal maintenance. However, ensure that roof gutters and valleys remain clear to prevent water pooling around the rooflight area, which could compromise the seal over time. Inspect the rooflight area periodically, particularly after severe weather, to confirm the flashing remains properly sealed.
- Not suitable for roof pitches exceeding 30 degrees
- Protect from damage during installation and roof work
- Keep gutters and roof valleys clear of debris
- Check periodically for signs of water ingress or seal failure
- Do not attempt to repair damaged flashing; replacement may be necessary