Fixing and buying guide
VELUX Twin and Combination Flashings 55x118cm EKL CK06 S0122
Who this product is for
This flashing kit is for installers and builders carrying out dual roof window installations on slate-covered roofs. It suits both new build and retrofit projects where two VELUX windows need to be fitted vertically aligned with proper weatherproofing. It is not suitable for single window installations or for use with other roof coverings such as tiles or felt.
- Professional installers and experienced DIY builders with roof window installation experience
- Projects requiring two roof windows in vertical alignment
- Natural slate roofs only, up to 8mm thickness
Compatibility and sizing
This kit is designed for VELUX roof windows with a 100mm gap between frames when installed vertically. The flashing dimensions are 55 × 118cm, which accommodates this standard dual window configuration. The kit works on roof pitches from 15° to 90°, covering steep pitches and shallow angles. Verify that your roof slate thickness does not exceed 8mm and that your chosen VELUX windows are compatible with this frame spacing before ordering.
- Roof pitch: 15° to 90°
- Frame gap: 100mm between window frames
- Slate thickness: up to 8mm maximum
- Flashing dimensions: 55 × 118cm
What is included and pre-installation checks
This is a complete kit containing all components required for weathertight installation of two vertically aligned roof windows into slate. Before installation, confirm that your roof pitch falls within the 15° to 90° range, measure your slate thickness to ensure it does not exceed 8mm, and verify the 100mm spacing between your window frames. Check that the roof structure can support dual window installation and that there are no obstructions or roof features that would prevent proper flashing placement.
- Complete flashing kit – all components included for dual window installation
- Measure roof pitch and slate thickness before fitting
- Confirm 100mm frame spacing matches your window configuration
- Inspect roof structure for suitability and clear any debris from the installation area
Installation considerations
Proper installation is critical for weatherproofing. The flashing must be integrated carefully with the slate profile to ensure water runs away from the window frames. The kit is designed to work with natural slate specifically; do not use on other roof coverings. Installation should be carried out by experienced builders or professional installers familiar with roof window flashing on slate roofs. Ensure all components are secured and sealed according to VELUX installation instructions to maintain the weathertight integrity of the installation.
- Natural slate roofs only – not suitable for tiles, felt, or other coverings
- Requires experienced installer familiar with roof window flashing
- All components must be secured and sealed for weatherproofing
- Follow VELUX installation instructions for correct assembly and positioning