Fixing and buying guide

What this product is and who it is for

This is a twin and combination flashing designed to seal the gap between your roof and roof penetrations. It prevents water ingress at vulnerable points where skylights, roof vents or chimneys pass through the roof surface. The product suits both timber and concrete pitched roofs. It is intended for homeowners and builders carrying out roof work to professional standards, or for experienced DIY users confident in roof-level work.

Compatibility and sizing

The 55 x 118cm dimensions accommodate standard roof applications and typical penetration sizes. Confirm that your roof penetration (skylight, vent or chimney) falls within the coverage area this flashing provides. Check whether your roof structure is timber or concrete, as this flashing is rated for both. Measure your roof pitch and penetration location to ensure the flashing will sit correctly and overlap properly with surrounding roof covering.

• Size: 55 x 118cm (21.6 x 46.1 inches)
• Suitable for timber and concrete roof surfaces
• Designed for skylights, vents and chimneys
• For pitched roof applications

Pre-installation checks

Before ordering or installing, verify the exact dimensions of your roof penetration and confirm the flashing will provide adequate overlap with surrounding roof tiles or covering. Check that you have the correct fixings specified by VELUX for your roof type. Inspect the roof area for any existing damage or deterioration that should be addressed before installation. Ensure you have access to the roof safely and that weather conditions are suitable for working at height.

• Measure your roof penetration accurately
• Confirm roof surface type (timber or concrete)
• Check you have appropriate fixings for your roof
• Inspect the installation area for damage

Installation and finish

Installation should be carried out in line with VELUX manufacturer guidance and current best practice standards. The flashing features a fade and crack-resistant finish designed to withstand exposure to weather and UV. Proper installation and use of recommended fixings are essential to achieve the watertight seal this product is engineered to provide. If you are not confident in roof work, engage a qualified roofer to carry out installation.