How and where to use guide
VELUX Twin and Combination Flashings 78x98cm EBW MK04 0021B
Typical applications and suitability
These flashings are specifically designed for timber frame roof construction where VELUX windows are being installed into pitched roofs. They are suitable for roofs up to 4m high and work in conjunction with other roofing materials such as tiles, slates, or sheet coverings. The twin and combination design accommodates different roof configurations and window arrangements. The EBW grade indicates reliable performance in demanding weathering applications.
- Pitched roof installations with VELUX windows
- Timber frame construction projects
- Roofs up to 4m in height
- Use with standard tile, slate, or sheet roof coverings
Installation and positioning
The flashing must be positioned to create a continuous weatherproof seal around the roof window opening. The 78x98cm dimensions are sized to work with standard window openings in this product range. Installation involves securing the flashing to the timber frame structure and integrating it with the surrounding roofing material. The flashing should be positioned so that water running down the roof surface is directed away from the window frame and into the roof covering below. Careful attention to overlap and sealing is critical to prevent water penetration at this vulnerable junction point.
- Position flashing to direct water away from window frame
- Ensure proper overlap with surrounding roof covering
- Secure firmly to timber frame structure
- Seal all joints and edges to prevent water ingress
Material properties and maintenance
The extruded aluminium construction provides excellent durability and natural weather resistance. Aluminium does not rust and maintains its integrity in harsh environmental conditions. The robust finish protects against UV exposure and temperature fluctuations typical of exposed roof positions. Maintenance is minimal; periodic inspection should check that the flashing remains securely fixed and that any sealant around joints remains intact. Clean debris from the flashing surface to maintain water drainage and prevent pooling.
- Aluminium construction resists corrosion and weathering
- Inspect regularly to ensure secure fixing and intact seals
- Clear debris to maintain water drainage
- Check sealant condition annually, particularly after severe weather
Limitations and on-site considerations
These flashings are designed for pitched roofs only and are not suitable for flat roof applications. The maximum roof height specification of 4m should be observed. The flashing must be used as part of a complete weatherproofing system with appropriate sealants and compatible roofing materials. Installation should be carried out by experienced roofers familiar with timber frame construction and VELUX window installation procedures. The flashing alone does not provide weatherproofing; it must be integrated correctly with the roof covering and window frame to function effectively.
- Pitched roofs only; not suitable for flat roofs
- Maximum roof height 4m
- Must be used with appropriate sealants and compatible roofing materials
- Requires skilled installation by experienced roofers