Fixing and buying guide

Who this product is for

This flashing is intended for builders, roofing contractors, and experienced DIY installers undertaking flat roof rooflight installations in UK properties. It is suitable for new builds and renovation projects where a VELUX rooflight up to 134cm wide and 140cm high is being fitted to a flat roof structure.

Compatibility and sizing

This flashing is designed specifically for VELUX rooflights with maximum dimensions of 134cm width and 140cm height. Before ordering, measure your rooflight opening carefully to confirm it does not exceed these limits. The timber construction is suitable for flat roof applications and meets UK construction industry standards. Check that your roof structure can accommodate the flashing depth and that the surrounding roof deck is sound and level.

• Maximum rooflight width: 134cm
• Maximum rooflight height: 140cm
• Material: Timber, grade EDW UK08 0000
• Application: Flat roofs only
• Verify rooflight dimensions before purchase

What is included and pre-installation checks

Each flashing is a single timber unit sized 134cm by 140cm. Before installation, inspect the flashing for any damage in transit and check that the timber is dry and free from warping. Examine your roof opening to ensure it is square, level, and the correct size for your rooflight. The surrounding roof deck must be structurally sound and properly prepared. Have all necessary sealants, fixings, and roofing membranes ready before you begin work.

• Inspect timber for damage and warping upon delivery
• Confirm roof opening is square and level
• Check roof deck is structurally sound
• Ensure all fixings and sealants are available before starting
• Correct installation is critical to prevent water ingress

Installation and weather protection

The flashing must be installed to create a complete weather-tight seal around the rooflight perimeter. This prevents water from penetrating the building structure and causing damage. Follow VELUX installation guidance carefully and ensure all joints and edges are properly sealed. The timber construction requires appropriate treatment and protection as part of your roofing system. Poor installation or incomplete sealing will compromise the weather-tightness of your roof and may lead to water damage.