How and where to use guide
VELUX Twin and Combination Flashings 78x98cm EKW MK04 S0122
Typical applications and where to use
These flashings are designed specifically for timber frame roof construction where EKW-graded timber is used. Install them around roof penetrations including chimneys, roof vents, soil pipes and skylights. The 78 x 98cm dimensions suit standard domestic and light commercial roof openings. The flashing works in conjunction with your existing roofing materials—whether tiles, slates or sheet coverings—to create a continuous weatherproofing system at vulnerable junction points.
- Chimneys and chimney stacks
- Roof vents and ventilation pipes
- Skylights and roof windows
- Soil pipes and waste outlets
- EKW timber frame construction only
Installation and positioning
Install the flashing according to manufacturer's instructions to ensure correct positioning and seal integrity. The flashing must sit properly within the roof opening, creating a secure junction between the penetration and surrounding roof surface. Position the flashing so that water is directed away from the timber frame and into the main roof drainage path. Ensure the flashing overlaps correctly with adjacent roofing materials to maintain the weatherproofing barrier.
- Follow manufacturer's installation instructions precisely
- Ensure flashing sits correctly in the opening
- Maintain proper overlap with surrounding roofing materials
- Direct water flow away from timber frame
- Check seal integrity before final roofing installation
Durability and maintenance
The timber-grade plastic construction provides durable, long-term weatherproofing resistance. Inspect flashings annually, particularly after severe weather, to ensure the seal remains intact and no water ingress has occurred around the junction. Clear any debris, moss or lichen that accumulates on the flashing surface, as this can trap moisture. The flashing requires no specialist maintenance but should be checked as part of routine roof inspections.
- Inspect annually for damage or seal deterioration
- Clear debris and organic growth from flashing surface
- Check for water staining or dampness in timber frame below
- Ensure no gaps have developed at junction points
- Replace immediately if damage is found
Limitations and important notes
This flashing is designed for timber frame construction with EKW-graded timber only. Do not use on other timber grades or non-timber frame construction without verification. The 78 x 98cm size is fixed and suits standard roof openings; larger or non-standard penetrations require alternative solutions. The flashing must be installed as part of a complete roofing system and cannot function as a standalone weatherproofing solution. Always follow building regulations and manufacturer's guidance for your specific application.
- EKW timber frame construction only
- Fixed size—not suitable for oversized openings
- Must be used with standard roofing materials
- Installation must comply with building regulations
- Not a standalone weatherproofing solution