How and where to use guide
VELUX Twin and Combination Flashings 66x118cm EKW FK06 S0122
Typical applications and suitability
This duo flashing is ideal for residential and commercial roof window installations where two windows need to be positioned one above the other on the same roof pitch. Common applications include stairwell lighting, dual-room ventilation, or maximising natural light in multi-storey spaces. The flashing is specifically engineered for clay and concrete tile roofs with a maximum profile height of 120mm, which covers most standard UK domestic and commercial tile specifications. The 100mm gap between windows is fixed and suits standard VELUX window spacing requirements.
- Suitable for clay and concrete tiles up to 120mm profile
- Designed for two 66×118cm VELUX roof windows in vertical alignment
- Maintains 100mm gap between upper and lower windows
- Eliminates need for custom site-built flashings
- Integrated weatherproofing reduces on-site sealing work
Installation and positioning
Position the flashing on the roof slope before installing the roof windows. The prefabricated design means the flashing is ready to fit without modification. Ensure the roof structure and tile layout accommodate the 66cm width and 118cm height dimensions. The flashing should be secured to the roof structure according to VELUX installation instructions, with tiles cut and fitted around the flashing perimeter. The integrated weatherproofing means you do not need to apply additional sealants around the flashing edges if installed correctly. Ensure the upper and lower window openings align precisely with the flashing apertures to maintain the weatherproofing integrity.
- Check roof pitch and tile profile before ordering
- Verify the 100mm gap suits your window spacing requirements
- Secure flashing to roof structure as per VELUX guidance
- Cut and fit tiles around the flashing perimeter
- Ensure window openings align with flashing apertures
Limitations and maintenance
This flashing is designed exclusively for the duo configuration with a fixed 100mm gap; it cannot be adjusted for different window spacing. It is not suitable for tile profiles exceeding 120mm or for slate, metal, or other roofing materials. The prefabricated design means it cannot be modified on site to suit non-standard roof layouts. After installation, inspect the flashing perimeter annually and after severe weather to ensure tiles remain secure and no gaps have developed. Clear any debris from the flashing edges and ensure gutters and downpipes are functioning to prevent water pooling.
- Fixed 100mm gap cannot be adjusted
- Not suitable for tiles with profiles over 120mm
- Not compatible with slate or metal roofing
- Cannot be cut or modified on site
- Annual inspection recommended for tile security and weatherproofing integrity