Fixing and buying guide
VELUX Twin and Combination Flashings 55x78cm EKJ CK02 S0021E
Compatibility and sizing
This flashing is sized 55×78cm and is designed specifically for VELUX flat rooflights of this dimension. It is compatible with timber roof decking grades of 28–32mm and 44–48mm thickness, and works with roofing felt layers up to 48mm. The flashing is rated for roof pitches up to 30 degrees. Before ordering, confirm your rooflighting dimensions and measure your existing timber deck and felt thickness to ensure compatibility.
- Flashing dimensions: 55×78cm
- Timber grade compatibility: 28–32mm and 44–48mm
- Roofing felt compatibility: up to 48mm
- Maximum roof pitch: 30 degrees
- Verify your VELUX rooflighting size matches this product
Product construction and durability
The flashing is manufactured from durable 4mm plastic, which provides long-term weather resistance and protection against water ingress. The plastic construction is lightweight, making it easier to handle during installation, whilst remaining rigid enough to maintain its shape and seal integrity over time.
- Material: 4mm plastic
- Lightweight and easy to handle
- Durable weathering protection
- Maintains seal integrity in exposed conditions
Pre-installation checks
Before fitting, inspect your roof structure to confirm timber deck thickness and roofing felt specification fall within the compatible ranges. Check that your roof pitch does not exceed 30 degrees, as the flashing is not rated for steeper pitches. Ensure the VELUX rooflighting opening dimensions match the 55×78cm flashing size. Verify that the area around the rooflighting is clear of debris and that the roof surface is clean and dry to allow proper seating of the flashing.
- Confirm timber deck is 28–32mm or 44–48mm thick
- Check roofing felt thickness is up to 48mm
- Measure roof pitch and confirm it does not exceed 30 degrees
- Verify rooflighting opening is 55×78cm
- Clean and dry the roof surface around the opening
Twin and combination design
The twin and combination design of this flashing allows flexibility in how it is installed across different flat roof build-ups. This means you can adapt the flashing to suit your specific roofing system configuration, whether you are working with different timber grades or felt thicknesses within the compatible range. This flexibility makes the product suitable for a variety of flat roof installations without requiring multiple different flashing types.
- Flexible installation across compatible timber and felt combinations
- Reduces the need for multiple flashing variants
- Adapts to your specific roof build-up