How and where to use guide
VELUX Underfelt Collar 66x118cm BFX FK06 1000
Typical applications and compatibility
This underfelt collar is designed specifically for VELUX roof window and Sun Tunnel installations on standard pitched roofs. It works by sitting between the window frame and the roof structure, creating a weather-tight seal that integrates with the roof covering. The collar is suitable for use in both new build construction and refurbishment work, making it versatile for various roofing projects across the UK.
- VELUX roof window installations on pitched roofs
- VELUX Sun Tunnel systems
- New build and refurbishment applications
- Standard pitched roof constructions
Installation and positioning
The collar must be positioned correctly to ensure effective drainage and weather protection. It sits beneath the roof covering and above the roof structure, with the integrated transverse drainage gutter directing water laterally away from the window installation. Proper positioning is critical to prevent water pooling around the window frame. The 660 x 1180mm dimensions are designed to accommodate standard VELUX window sizes, so verify compatibility with your specific window model before installation.
- Position collar between window frame and roof structure
- Ensure transverse drainage gutter is correctly oriented to direct water sideways
- Confirm compatibility with your VELUX window model
- Integrate with roof covering to create seamless weather seal
Weather protection and drainage
The integrated transverse drainage gutter is the key feature of this collar, designed to manage water run-off and prevent water ingress. The aluminium construction provides durability in typical UK roof conditions. The drainage channel must remain clear of debris and moss to function effectively, particularly in areas prone to heavy rainfall or where roof debris accumulates.
- Integrated drainage gutter prevents water pooling around window frame
- Aluminium construction resists corrosion in UK weather conditions
- Keep drainage channel clear of leaves, moss and debris
- Check drainage function during maintenance visits
Maintenance and on-site considerations
Regular inspection of the collar and its drainage channel is essential to maintain weather-tight performance. Clear any accumulated debris from the transverse gutter to ensure water flows freely away from the installation. During refurbishment work, ensure the collar is properly integrated with existing or new roof covering materials. Store the collar flat and protected from damage before installation to avoid denting the aluminium or obstructing the drainage channel.
- Inspect collar and drainage gutter annually
- Clear debris from transverse drainage channel
- Ensure proper integration with roof covering materials
- Store flat and protected from impact damage before use