Fixing and buying guide
VELUX Twin and Combination Flashings 94x140cm EBW PK08 0021B
What this product is and who needs it
A twin and combination flashing is a metal or composite frame that sits between your roof windows and roofing material to create a watertight seal. You need this product if you are installing two VELUX roof windows positioned side by side with approximately 18mm spacing between them. It replaces the need for two separate individual flashings and is fitted during the installation process before the roofing material is laid or replaced around the windows.
- For dual roof window installations only, not single windows
- Creates the weather-tight seal between window frame and roof surface
- Fitted before roofing material is installed or replaced
Compatibility and roof requirements
This flashing is compatible with most common UK roofing materials and a broad range of roof pitches. It works with concrete and clay roof tiles, interlocking slate, thatch, and profiled metal sheeting. The maximum roofing profile depth it can accommodate is 120mm, which covers standard corrugated and box profile metal sheets. The flashing is engineered for roof pitches between 15° and 90°, making it suitable for nearly all domestic pitched roofs and many commercial installations.
- Compatible with tiles, slate, thatch and profiled sheeting
- Handles roofing profiles up to 120mm deep
- Suitable for pitches from 15° to 90°
- Check your roof pitch and material type before ordering
Sizing and window spacing
The flashing dimensions are 94x140cm and are designed specifically for two roof windows with an 18mm gap between them. This spacing is critical for proper installation and weather performance. Before purchase, measure the combined width of both windows plus the 18mm gap to ensure this flashing is the correct size for your installation. Verify that both windows are VELUX units and that they will be positioned at the correct spacing.
- Dimensions: 94x140cm
- Designed for 18mm spacing between two windows
- Measure your window positions before ordering
- Product code: EBW PK08 0021B
Pre-installation checks
Before fitting, confirm that your roof pitch falls within the 15° to 90° range and that your roofing material profile does not exceed 120mm depth. Check that you have two VELUX windows ready for installation and that the installation area is clear of debris and old flashing. Ensure you have the correct tools and fixings for your specific roofing material type, as these may vary between tiles, slate, thatch and metal sheeting. Read the VELUX installation instructions carefully, as proper fitting is essential for weather performance.
- Verify roof pitch is between 15° and 90°
- Confirm roofing profile depth does not exceed 120mm
- Check both windows are VELUX units
- Prepare the installation area and gather material-specific fixings
- Follow VELUX installation instructions precisely