How and where to use guide
VELUX Underfelt Collar 55x118cm BFX CK06 1000
Where to use this product
This underfelt collar is specifically designed for flat roof rooflight installations using VELUX windows. The 55cm x 118cm dimensions suit a range of roof types and project scales. The collar sits beneath the rooflight frame, creating a weather-tight seal at the interface between the rooflight and the roof structure. It is essential for protecting against wind-driven rain penetration around the rooflight opening on flat roof applications.
- Flat roof rooflight installations only
- VELUX rooflight systems
- Suitable for various roof types and project scales
- Positioned beneath rooflight frame as part of flashing assembly
Installation and application
Before ordering, confirm that the 55cm x 118cm dimensions match your project specification and rooflight requirements. Install the underfelt collar using suitable fixings in line with current site practice and manufacturer guidance. The collar should be positioned to create a continuous weather-tight seal around the rooflight opening. Ensure the polypropylene material sits flat and secure all fixings properly to prevent wind-driven rain from penetrating beneath the collar.
- Verify dimensions against your rooflight specification before installation
- Use suitable fixings appropriate to your roof construction
- Follow current site practice and VELUX manufacturer guidance
- Ensure collar sits flat with no gaps or lifting
- Secure all fixings to prevent weather penetration
Material properties and durability
The collar is manufactured from durable polypropylene with a weather-resistant coating, providing long-term protection against exposure to the elements. This material combination ensures the collar can withstand harsh weather conditions typical of UK flat roof installations. The weather-resistant coating helps prevent degradation from UV exposure and moisture, maintaining the integrity of the weather-tight seal over time.
- Polypropylene construction provides durability and flexibility
- Weather-resistant coating protects against UV and moisture damage
- Designed to withstand harsh weather exposure on flat roofs
- Maintains weather-tight seal integrity throughout service life
On-site tips and maintenance
After installation, periodically inspect the collar and surrounding flashing to ensure the weather-tight seal remains intact. Check that all fixings remain secure and that no gaps have developed around the rooflight opening. Keep the collar and surrounding roof area clear of debris and standing water, which could compromise the seal. If damage to the polypropylene or coating is observed, plan for replacement to maintain rooflight weatherproofing.
- Inspect collar regularly for signs of damage or seal failure
- Check fixings remain secure and tight
- Keep roof area around rooflight clear of debris
- Prevent standing water accumulation near the collar
- Replace if polypropylene or coating becomes damaged