How and where to use guide
VELUX Insulation Collar 78x140cm BDX MK08 2000
Installation and Compatibility
The BDX MK08 2000 collar is engineered specifically for use with compatible VELUX roof window and Sun Tunnel ranges. Before ordering, confirm your roof window model number matches the MK08 specification and that your collar dimensions of 780 x 1400mm align with your installation requirements. The collar must be installed during the roof window fitting process to ensure a proper weather-tight seal. Always follow VELUX installation guidance alongside this collar to guarantee correct positioning and fastening.
- Check your VELUX roof window or Sun Tunnel model is compatible with the MK08 collar specification
- Install the collar as part of the complete roof window assembly, not as a standalone product
- Ensure the collar sits flush against the roof structure to maintain weather-tightness
- Use appropriate fixings and sealants recommended by VELUX for your roof type
Weather Protection and Roof Finish
The primary function of this insulation collar is to provide weather-tight flashing that prevents water penetration around the roof window opening. It also creates a professional, visually consistent appearance across your roof line, which is particularly important in refurbishment work where the new window must blend with existing roof details. The collar is engineered to perform reliably in typical UK roof conditions, including exposure to rain, wind, and temperature fluctuations.
- Position the collar to overlap roof covering materials correctly, following local building practice
- Ensure all edges are sealed to prevent water ingress at the perimeter
- The collar supports a neat finish that maintains the visual integrity of your roof
Applications and Project Types
This collar is suitable for new build properties where roof windows are being installed as part of the initial construction, and for refurbishment projects where existing roof windows are being replaced or new windows added to existing roofs. In both cases, the collar ensures compliance with weather-tightness requirements and provides a professional installation standard.
- New build: Install during roof construction before final roof covering is applied
- Refurbishment: Use when replacing existing roof windows or adding new windows to established roofs
- Works as part of a wider daylight and ventilation solution when paired with compatible VELUX products
On-Site Handling and Maintenance
Store the collar in dry conditions on site before installation to prevent damage or contamination. Once installed, the collar requires no routine maintenance beyond ensuring that the roof covering and sealants around it remain in good condition. Periodically check that the collar edges remain sealed and that no debris has accumulated around the window perimeter, particularly after severe weather.
- Keep the collar protected from weather and site damage until installation
- Inspect sealants and fixings annually, especially after winter or high winds
- Clear any moss, leaves, or debris from around the window collar to maintain water drainage