Fixing and buying guide

What this product is and who it is for

This is a recessed flashing system for flat roof applications. It creates a weather-tight seal around roof openings to prevent water ingress and maintain structural integrity. The product suits professional roofers installing VELUX windows or roof lights, and experienced DIY customers undertaking serious roofing projects who are confident working at height and following technical specifications.

Sizing and compatibility

The flashing measures 94 x 160cm overall and is designed for roof openings of 47 x 100mm. You must verify your actual roof opening dimensions match this specification before ordering. Check the opening size carefully, as incorrect sizing will compromise the weather seal and may result in water damage. If your opening differs, contact the supplier to confirm the correct flashing size for your project.

What is included and pre-installation checks

This pack contains the recessed flashing unit. You will need to source appropriate fixings separately to secure the flashing to your roof structure, following VELUX manufacturer guidance. Before installation, inspect the flashing for any damage in transit, confirm roof opening dimensions one final time, and ensure the surrounding roof surface is clean, dry and level. Check that you have all necessary tools and fixings to hand, and review the full manufacturer installation instructions.

Installation and best practice

Install this flashing in line with current best practice and VELUX manufacturer guidance. The recessed design must be positioned correctly to ensure effective water shedding. Use suitable fixings appropriate to your roof construction, and ensure the seal is complete and secure. If you are not confident working on roofs or following technical specifications, engage a qualified roofer. Poor installation will compromise weather protection and may void any warranty.

• Work safely at height with appropriate fall protection
• Follow all VELUX manufacturer instructions precisely
• Use fixings recommended for your roof type and structure
• Ensure the recessed design is correctly oriented for water run-off
• Check the seal is complete before considering the job finished