How and where to use guide

VELUX Vapour Barrier 55x98cm BBX CK04 0000

Typical applications and installation location

The vapour barrier collar is installed around VELUX roof windows and Sun Tunnel systems at the point where they penetrate the roof structure. It sits between the roof covering and the window frame, creating a continuous seal that protects the building envelope from weather exposure. This product is used in both new build installations where roof penetrations are being created and in refurbishment projects where existing windows are being replaced or upgraded. The collar ensures that water, wind-driven rain and moisture cannot bypass the window installation and enter the roof void or interior spaces.

Install around VELUX roof windows and compatible Sun Tunnel systems
Position at the roof penetration point between roof covering and window frame
Use in new build projects during initial roof construction
Use in refurbishment and replacement installations
Suitable for pitched roofs in UK climate conditions

Installation and positioning

The 550×980mm collar must be positioned correctly to function effectively. It should be installed as part of the complete VELUX system, working in conjunction with the window frame and roof covering materials. Proper positioning ensures the collar creates a continuous barrier against moisture whilst allowing the roof covering to sit flush and maintain a professional appearance. The collar dimensions are designed to accommodate standard VELUX roof window and Sun Tunnel sizes, so compatibility with your specific VELUX product is essential before ordering.

Confirm compatibility with your specific VELUX roof window or Sun Tunnel model before installation
Install as part of the complete VELUX system following manufacturer guidance
Position to create a continuous seal at the roof penetration
Ensure roof covering sits properly over the collar for weather protection
Check that the collar sits flush with surrounding roof materials for professional finish

Weather protection and maintenance

The vapour barrier collar is engineered to maintain its performance in typical UK roof conditions, including exposure to rain, wind and temperature fluctuations. Once installed correctly as part of the complete system, the collar requires no special maintenance. However, it is important to inspect the installation periodically, particularly after severe weather, to ensure the seal remains intact and the roof covering has not shifted. Any gaps or movement should be addressed promptly to prevent moisture ingress.

Inspect the installation after severe weather or high winds
Check that the roof covering remains properly seated over the collar
Ensure no gaps have developed between the collar and window frame
Address any visible damage or movement immediately
Do not attempt to modify or cut the collar as this will compromise the weather-tight seal

Limitations and important considerations

This vapour barrier collar is designed specifically for use with compatible VELUX roof window and Sun Tunnel systems. It cannot be used with other manufacturers' products and will not function correctly if installed with incompatible window frames or systems. The collar is a component part of the complete installation and must be used alongside other VELUX components to achieve the intended weather-tight seal and professional finish. Always verify product compatibility before purchase and follow VELUX installation instructions carefully.

Only use with compatible VELUX roof windows and Sun Tunnel systems
Not suitable for use with other manufacturers' roof window products
Must be installed as part of the complete VELUX system
Do not use as a standalone product without compatible window frame
Refer to VELUX installation documentation for your specific window model