Fixing and buying guide

What this product is and who needs it

Roof window flashings are metal or composite components that bridge the gap between a roof window frame and the surrounding roof covering. This flashing kit is specifically engineered for slate roofs and Velux 2-in-1 studio windows. It prevents rainwater from running behind the window frame and into the building fabric. You need this product if you are installing a new Velux 2-in-1 studio window into a slate roof, or replacing an existing flashing during refurbishment work. Without proper flashing, water damage and damp problems will develop.

Compatibility and sizing

This flashing is designed exclusively for Velux EDLS FFK08 2000 Pro+ 2-in-1 studio windows. The overall dimensions are 1270×1400mm, which corresponds to the window opening size. Check your window model number and opening dimensions before purchase to ensure compatibility. The kit includes both BDX and BFX components, which are the upper and lower flashing elements needed for a complete installation. Do not attempt to use this flashing with other window brands or models, as the fixing points and profiles will not align.

• Confirm your window is a Velux 2-in-1 studio system
• Verify the opening size matches 1270×1400mm
• Check that your roof covering is slate tiles
• Both BDX and BFX components are included in this kit

What is included and pre-installation checks

This kit contains the BDX and BFX flashing components required for a complete weather-tight installation. Before you begin, ensure the roof opening is cut to the correct size and that the surrounding slate tiles are sound and properly secured. The roof structure must be level and stable. Inspect the window frame for any damage or defects. Have all fasteners, sealants, and any additional roof tiles or battens you may need close to hand. Check weather forecasts and plan installation for dry conditions, as flashing installation requires careful sealing and should not be carried out in heavy rain.

• Unpack and inspect both BDX and BFX components for damage
• Verify the roof opening is cut to the correct size
• Check that surrounding slate tiles are secure and in good condition
• Ensure the roof structure is level and stable
• Gather all fasteners, sealants, and roof tiles before starting work

Installation and professional finish

This flashing kit is engineered to deliver a neat, professional finish that integrates visually with slate roof coverings. The BDX and BFX components must be installed in the correct sequence and secured firmly to prevent movement and water leakage. Proper sealing with appropriate roof sealant is essential. If you are not experienced in roof window installation, we recommend engaging a qualified roofer or Velux installer to carry out the work. Poor installation will compromise the weather-tight seal and may lead to costly water damage. The flashing is suitable for typical UK roof conditions and will provide reliable performance when installed correctly.