Fixing and buying guide

Who this product is for

This flashing is intended for anyone installing or replacing a Velux roof vent, whether you are a trade professional or a serious DIY customer. It is particularly useful if you need flexibility in positioning or are working with standard vent dimensions on timber-framed roofs.

Compatibility and sizing

The 55cm × 78cm size accommodates standard Velux vent dimensions. Before purchasing, confirm your vent size matches these specifications. The flashing is compatible with FSC 118 timber grades or equivalent structural timbers. Check your roof timber specification before ordering. Multiple finish options are available, so select the finish that matches your existing roofing materials and aesthetic requirements.

• Confirm your Velux vent dimensions match 55cm × 78cm
• Verify your roof timber is FSC 118 grade or equivalent
• Choose a finish option that complements your roofing material

What is included and installation features

The twin and combination design of this flashing enables easy installation and on-site adjustment. The combination feature means it can accommodate different vent configurations, reducing the need for multiple flashing types on mixed installations. The plastic material provides durability and the watertight seal prevents water ingress around the vent opening.

• Twin design allows straightforward positioning and adjustment
• Combination feature suits different vent sizes and configurations
• Plastic construction ensures durability and weather resistance
• Creates a watertight seal to prevent water penetration

Pre-installation checks

Before fitting, ensure your roof opening is prepared to the correct dimensions and that the surrounding timber is sound and dry. Check that all roofing materials and underlays are in place. Inspect the flashing for any damage during delivery. Have all necessary fixings and sealants to hand before beginning installation, and follow Velux installation guidance specific to your roof type and pitch.