Fixing and buying guide

What this product is and who it is for

This is a standard flashing kit for sealing Velux rooflights against water ingress. It is designed for flat roof and wall installations where a rooflight penetrates the building envelope. The flashing suits both trade professionals and experienced DIY installers who are confident working at height and with roofing materials. It is not suitable for pitched roofs or installations exceeding 4m in height.

Compatibility and sizing

This flashing is engineered for Velux rooflights and must be used with compatible Velux window units. The 1000mm x 200mm profile is the standard size for this flashing type. The flashing is compatible with timber structural grades F16 and above, which covers standard building-grade timber used in domestic and light commercial construction. Check your roof structure meets this timber grade before installation.

• Designed specifically for Velux rooflight models
• Profile dimensions: 1000mm long x 200mm wide
• Requires timber grade F16 or above
• Suitable for flat roofs and walls only, up to 4m height

Pack contents and material

The flashing is manufactured from PVC, a durable plastic material that resists weather damage, UV exposure, and water penetration. PVC flashings require no painting or staining and maintain their performance over extended periods. The product is supplied as a single flashing unit ready for installation around your rooflight.

Pre-installation checks

Before fitting, verify that your roof structure is sound and that the rooflight opening is correctly sized for this flashing. Ensure the surrounding roof or wall surface is clean and free from debris. Check that your timber structure meets grade F16 or above. Confirm the installation height does not exceed 4m. Have appropriate safety equipment and fall protection in place before working at height.

• Confirm Velux rooflight compatibility
• Verify timber grade F16 or above in roof structure
• Check installation height is within 4m limit
• Inspect rooflight opening for correct dimensions
• Ensure roof surface is clean and ready for flashing installation