How and where to use guide
VELUX Twin and Combination Flashings 134x98cm EKL UK04 S0222
Suitable applications and roof types
These flashings are designed for pitched roof installations where roof penetrations such as pipes, vents, or windows require weather-tight sealing. They work effectively with felt, slate, and metal roofing materials commonly found on UK residential and commercial buildings. The flashings are compatible with structural timber graded F16, F24, and F36, making them suitable for a range of roof construction types. Installation is appropriate for roofs with a minimum pitch angle of 30 degrees; steeper pitched roofs provide better water run-off and are ideal for these flashings.
- Pitched roofs with minimum 30 degree pitch angle
- Roof penetrations including pipes, vents, and window installations
- Felt, slate, and metal roofing materials
- Timber grades F16, F24, and F36
- Roof lengths up to 4 metres
Installation and on-site guidance
Install flashings before laying the final roofing material to ensure proper overlap and weather protection. Position the flashing around the roof penetration, ensuring it sits flush against the timber structure and underlying roofing layers. The flashing dimensions of 134 by 98 centimetres provide adequate coverage for standard roof penetrations. Secure the flashing firmly to prevent movement during installation and subsequent weather exposure. Ensure the flashing overlaps correctly with the roofing material above and below the penetration point to direct water away from the building interior.
- Install before final roofing material is laid
- Position flush against timber structure
- Ensure proper overlap with roofing materials above and below penetration
- Secure firmly to prevent movement
- Check alignment and fit before final fastening
Maintenance and durability
The robust construction of these flashings delivers long-lasting weather protection in harsh UK weather conditions. Periodically inspect the flashing and surrounding roofing material for signs of damage, deterioration, or water ingress, particularly after severe weather. Keep the roof area clear of debris and ensure gutters and downpipes are functioning correctly to prevent water pooling around the flashing. Any gaps or separation between the flashing and roofing material should be sealed promptly to maintain weather-tightness.
- Inspect regularly for damage or deterioration
- Check after severe weather events
- Keep roof area clear of debris
- Ensure gutters and downpipes function correctly
- Seal any gaps or separation promptly
Limitations and important considerations
These flashings are designed specifically for pitched roofs with a minimum pitch angle of 30 degrees. Do not use on roofs below this pitch angle as water run-off may be insufficient and weather protection compromised. The maximum roof length accommodation is 4 metres; for longer roof runs, plan multiple flashing installations. Ensure the timber structure is graded F16, F24, or F36 before installation. The flashing is engineered for use with felt, slate, and metal roofing materials only; compatibility with other roofing types should be verified before installation.
- Minimum roof pitch 30 degrees required
- Not suitable for flat or low-pitch roofs
- Maximum roof length 4 metres per flashing
- Verify timber grade F16, F24, or F36 before installation
- Confirm roofing material compatibility before use