How and where to use guide
VELUX Twin and Combination Flashings 78x118cm EBW MK06 0021B
Typical applications
This flashing is designed for use in timber frame construction projects where weather protection around openings and joints is required. The compact 78×118cm size makes it particularly suitable for smaller residential buildings, extensions, and restricted-space installations. It is installed on the exterior of the building envelope to protect vulnerable junctions where moisture ingress is most likely to occur.
- Sealing around roof vents and chimney penetrations in timber frame buildings
- Protecting joints and openings in the external building envelope
- Smaller buildings and space-constrained construction sites
- Timber frames up to 120mm thick
Installation and positioning
The flashing must be installed on the exterior of the building envelope to function effectively. Position it to create a continuous watertight seal around the opening or joint it is protecting. The zinc-coated steel construction ensures the flashing will resist corrosion when exposed to external weather conditions. Ensure the flashing is secured firmly in place and that all edges are properly sealed to prevent wind-driven rain from penetrating behind the flashing.
- Install on the exterior face of the building envelope only
- Position to overlap adjacent materials and direct water away from the opening
- Secure firmly to prevent movement and maintain the watertight seal
- Seal all edges and joints to prevent moisture ingress
Maintenance and durability
The zinc-coated steel construction provides excellent corrosion resistance, making this flashing suitable for long-term exterior use in UK weather. Inspect the flashing periodically to ensure the seal remains intact and that no gaps or damage have developed. The Grade B24 exterior specification confirms this product is rated for external building envelope applications. Keep the flashing clear of debris and ensure water can flow freely away from the protected opening.
- Zinc coating provides durable corrosion resistance in external conditions
- Check periodically that seals remain intact and watertight
- Clear debris from around the flashing to maintain water drainage
- Grade B24 exterior specification confirms suitability for exposed building envelope use
Limitations and site considerations
This flashing is designed specifically for timber frames up to 120mm thick; do not use on thicker timber frames as it will not provide adequate coverage. The 78×118cm size is compact and suited to smaller openings and buildings; larger installations may require multiple flashings or alternative products. Always ensure the flashing is installed on the exterior of the building envelope, as interior installation will not provide the necessary weather protection. On-site, protect the flashing from damage during construction and ensure it is not covered or obscured before the building envelope is fully sealed.
- Suitable for timber frames up to 120mm thick only
- Compact size suited to smaller buildings and restricted spaces
- Must be installed on the exterior of the building envelope
- Protect from damage during construction and ensure it remains accessible for inspection