Flashing and installation products
Every roof installation job requires skill and experience as well as the right tools and materials.
The VELUX installation product system is designed and optimised to support the installation workflow.
By using the complete VELUX installation product system, you can achieve the best possible results.
VELUX installation product system
- Flashings
Fit exact window dimensions and connect perfectly to your roofing material. Underfelt collar (type BFX) and insulation collar (BDX) are included with the flashing (2000 variant). - Underfelt collar
Pleated underfelt collar (type BFX) forms a tight seal between roof window and your felt underlay. Comes with adjustable drainage gutter to lead water away from the head of the roof window. - Insulation collar
Insulation collar (type BDX), with flexible foam for a tight and secure fit to the roof construction. - Vapour barrier collar and lining sub-construction
Vapour barrier collar (type BBX) for a vapour and airtight solution. The lining sub-construction gives a faster and better lining installation. - Interior lining
Prefabricated linings (type LSB/LSC/LSD) for easy and airtight inside completion. Includes vapour barrier collar (type BBX).
Flashings for all roof types
VELUX has flashing types that fit every roofing material and window size. Each flashing is precision-made to fit the window and makes the installation quick and simple.
The VELUX roof windows can be installed in two installation heights, standard or recessed. Choose a flashing type for recessed installation (40 mm lower in the roof), if you want a better insulation effect and a more visually appealing installation.
Choose the Pro flashing set (1000 variant) that includes the BFX underfelt collar for a weather-proof installation. Or if you want added insulation, choose the Pro+ flashing set (2000 variant) that also includes the BDX insulation collar. Both flashing sets have been carefully designed to make every step of the installation process as simple as possible.
Insulation frame and underfelt collar
The insulation frame BDX insulates around the roof window frame, reducing heat loss and eliminating cold bridges. The combination of rigid and flexible foam ensures a tight, energy-efficient installation to the roof construction.
The flexible insulation frame can be compressed for quick installation.
The underfelt collar BFX ensures a perfect fit and watertight seal between the roof window, battens, and the roofing underfelt. It is easy to fit. Simply place on top of the roof window and unfold.
An adjustable and self-supporting drainage gutter is included in the BFX. This leads the water away from the head of the roof window if there is a leak above.
Vapour barrier collar
The lining sub-construction can be mounted directly onto the window in less than five minutes, providing a sturdy framework that holds the lining boards securely in place while making it easy to cut them to the exact size required. This ensures a precise, professional finish and helps save valuable time during installation compared to traditional methods.
The lining sub-construction reduces cold bridges around roof windows by creating additional space for insulation. Thanks to its perpendicular design at the top and bottom, you get an extra 70 mm of space for insulation.
When used with the BBX vapour barrier collar, it provides long-lasting protection of the roof construction and roof window installation against damp and condensation. The rubber seals and welded corners of the vapour barrier ensure a vapour-tight and airtight solution. Furthermore, it comes with an innovative application tool, so it is fast and easy to fit in a single one-step procedure.
Interior lining
If you want a ready-made solution to complete the interior finish in the room, VELUX linings are easy to install and there is no need for additional painting. Made from durable PVC material, VELUX linings are water-resistant and maintenance-free and fit perfectly with the roof window. The unique design allows space for extra insulation material to prevent cold bridges.
VELUX linings are delivered with VELUX vapour barrier collar BBX.
Combination of roof windows
If you want to install roof windows in combination, the combination flashing system lets you do so efficiently. The system can be used for combining all the main roof window types however you prefer.
The a-distance:
- Our innovative and patented solution makes roof window combination installations more straightforward.
- The middle gutter can be adjusted to widths between 100 - 160 mm (M width), ensuring that it always fits to the actual rafter dimensions.
- Other frame distances between 60 mm to 400 mm can be specially ordered
The b-distance:
- Standard frame distance 100 mm (E)
- When installing a roller shutter, a frame distance of 250 mm (J) is needed