How and where to use guide
VELUX Insulation Collar 55x118cm BDX CK06 2011
Typical applications and installation
This insulation collar is used during the installation of VELUX roof windows in timber-framed construction. It is positioned around the window frame opening to bridge the gap between the frame and the surrounding wall structure. The collar creates a continuous seal that prevents draughts and water penetration at this critical junction. Installation should be carried out as part of the standard VELUX roof window fitting process, following the manufacturer's installation instructions to ensure the collar sits flush and secure against both the window frame and wall elements.
- Install between VELUX roof window frame and wall structure during window fitting
- Position collar to create continuous seal around entire frame perimeter
- Ensure collar sits flush against both frame and surrounding timber construction
- Use in timber-framed buildings only, as designed for this construction type
- Install before final weatherproofing and internal finishes are applied
Weatherproofing and thermal performance
The collar's primary function is to eliminate air leaks and prevent moisture ingress at the window-to-wall interface. By creating a tight seal, it significantly reduces heat loss through this vulnerable junction, improving the overall thermal efficiency of the building envelope. This is particularly important in timber-framed construction where gaps around window openings can substantially compromise insulation performance. The weatherproof seal also protects the timber frame and surrounding structure from water damage caused by wind-driven rain or condensation.
- Prevents air leakage around window frame, reducing heating and cooling losses
- Blocks moisture ingress that could damage timber frame and insulation
- Improves building thermal efficiency when installed correctly
- Protects structural timber from water damage and decay risk
Compatibility and on-site handling
This collar is specifically designed for VELUX roof windows and is sized at 55 x 118cm to match the CK06 2011 window specification. Before ordering, confirm the exact VELUX window model and size to ensure correct collar compatibility. On site, store the collar in dry conditions to prevent warping or moisture absorption. Handle carefully to avoid damage to the timber, as any splits or deformation will compromise the seal quality. Check that the collar is not damaged before installation begins.
- Confirm VELUX window model and size match before purchase
- Store in dry conditions away from weather exposure prior to installation
- Inspect collar for damage, splits or warping before fitting
- Handle carefully to preserve timber integrity and seal quality
Limitations and maintenance
This collar is engineered specifically for timber-framed buildings and VELUX roof windows. It is not suitable for use with other window types or in non-timber construction. Once installed and sealed, the collar requires no ongoing maintenance beyond ensuring that external weatherproofing (such as flashing and sealant) remains intact. If the collar becomes damaged after installation, it may be difficult to replace without removing the window, so careful handling during and after installation is important. The collar's effectiveness depends entirely on proper installation and a complete seal around the entire frame perimeter.
- For use only with VELUX roof windows in timber-framed construction
- Not suitable for other window types or alternative building structures
- Requires no routine maintenance once correctly installed
- Damage during or after installation may necessitate window removal for replacement