How and where to use guide
VELUX Twin and Combination Flashings 55x98cm EBP CK04 0021B
Typical applications and installation locations
These flashings are designed for timber frame roof construction where penetrations or junctions require weatherproofing. Install around roof penetrations such as pipes, vents, or structural timber connections where water ingress poses a risk. The twin and combination flashing design accommodates various roof configurations, making it suitable for standard residential and light commercial applications. The 55 x 98cm size is appropriate for typical roof penetration scenarios in domestic construction.
- Roof penetrations and timber frame junctions in pitched roofs
- New build and renovation projects with timber frame construction
- Roofs pitched between 30° and 60°
- Integration with existing VELUX roofing system products
Installation and positioning
Position the flashing to create a complete watertight seal around the roof penetration or timber junction. The combination design allows flexibility in accommodating different roof configurations. Ensure the flashing is correctly oriented for your specific roof pitch within the 30° to 60° range, as this affects water run-off and seal integrity. The PVC and timber components must be secured firmly to prevent movement during weather exposure or thermal cycling.
- Verify your roof pitch falls within the 30° to 60° specification before installation
- Position flashing to overlap correctly with surrounding roof covering
- Secure all components firmly to prevent wind lift or movement
- Ensure watertight seal is complete around the entire penetration
Material durability and maintenance
The combination of high-quality PVC and FSC-certified timber provides long-term durability in exposed roof conditions. PVC components resist UV degradation and weather damage, whilst the timber elements are sustainably sourced and treated for outdoor use. Periodically inspect the flashing for any gaps, cracks, or separation, particularly after severe weather. Clear any debris such as leaves or moss that may accumulate around the flashing, as this can trap moisture and compromise the seal.
- Inspect annually for signs of wear, gaps, or separation
- Clear debris and moss growth to maintain water drainage
- Check PVC seals remain intact and flexible
- Address any damage promptly to prevent water ingress
Limitations and important considerations
This flashing is specifically designed for roof pitches between 30° and 60°. Do not use on roofs outside this pitch range, as water run-off and seal performance cannot be guaranteed. The 55 x 98cm size is suitable for standard applications; larger or unusually shaped penetrations may require multiple flashings or custom solutions. Ensure compatibility with your existing VELUX roofing system components for optimal integration and performance.
- Not suitable for roof pitches below 30° or above 60°
- Confirm size is appropriate for your specific penetration before purchase
- Verify compatibility with your VELUX roofing system
- Do not modify or cut the flashing without professional guidance