Fixing and buying guide

Who these flashings are for

These flashings are suitable for builders, roofers, and experienced DIY installers carrying out Velux roof vent installations. They are designed for both domestic and commercial roofing applications where a reliable weather-tight seal is essential.

Compatibility and sizing

These flashings are specifically designed for Velux twin and combination roof vents. Check that your roof pitch does not exceed 30 degrees, as these flashings are rated for pitched roofs up to this angle. The 78 x 140cm size is the standard dimension for typical Velux vent installations. Confirm your timber grade is FSC 32mm or 44mm before purchase, as the flashing profile is engineered for these thicknesses.

• Maximum roof pitch: 30 degrees
• Timber grade compatibility: FSC 32mm or 44mm only
• Size: 78 x 140cm
• Material: PVC construction

Pre-installation checks

Before fixing, inspect the roof vent opening and surrounding timber to ensure they are sound and free from rot or damage. Verify that your roof pitch falls within the 30-degree maximum specification. Check that the timber frame is the correct FSC grade and thickness. Ensure you have all necessary roofing sealants and fixings to hand, as these are not included with the flashing itself.

• Confirm roof pitch does not exceed 30 degrees
• Check timber grade and thickness match FSC 32mm or 44mm
• Inspect roof vent opening for damage or deterioration
• Gather roofing sealants and fixings before starting installation

Installation overview

The flashing is installed around the perimeter of the roof vent to create a weather-tight seal. Position the flashing carefully to ensure it sits flush with the roof surface and timber frame. The PVC construction allows for secure fixing and reliable long-term performance in exposed conditions. Follow Velux installation guidance for your specific vent model to ensure correct positioning and sealing.