Fixing and buying guide

What this product is and who it is for

Twin and combination flashings are specialised sealing components designed specifically for VELUX skylight installations. They bridge the gap between the skylight frame and the roof structure, preventing water ingress and ensuring weathertightness. These flashings are essential for both new skylight installations and replacements, and are suitable for builders, roofers, and experienced DIY installers working on residential or commercial pitched and flat roof projects.

Compatibility and sizing

This flashing is designed for VELUX skylights and is compatible with timber roof structures graded F16 or higher. The 66cm × 118cm dimensions provide ample coverage for most standard skylight installations. Before ordering, confirm your skylight model and roof type (pitched or flat) to ensure this flashing is the correct specification for your application. Check your VELUX documentation or existing flashing to verify compatibility.

• Width: 66cm
• Length: 118cm (2' × 3'6")
• Timber grade requirement: F16 or higher
• Suitable for pitched and flat roof applications

Material and weather resistance

The flashing is constructed from weather-resistant PVC with a protective coating designed to withstand prolonged exposure to rain, wind, and UV radiation. This material choice ensures the flashing maintains its integrity and performance over many years without degradation, providing reliable long-term protection for your skylight installation.

Pre-installation checks

Before fitting, inspect the flashing for any damage during transit and ensure your roof timber meets the F16 grade requirement or higher. Verify that your VELUX skylight model is compatible with this twin and combination flashing specification. Check that the roof structure is sound and properly prepared according to VELUX installation guidelines. Have all necessary roofing materials and sealants to hand before beginning installation.

• Confirm VELUX skylight model compatibility
• Check roof timber grade is F16 or higher
• Inspect flashing for transport damage
• Ensure roof structure is sound and ready for installation