Fixing and buying guide

What this product is and who needs it

This is a purpose-designed flashing kit for installing VELUX rooflights and skylights into timber-framed walls and roof structures. It is essential for any builder, surveyor, or serious DIY customer installing or replacing VELUX windows in timber-frame buildings. The flashing creates a weather-tight seal that prevents rain and moisture from penetrating around the window opening, protecting the timber structure and interior finishes from water damage.

Compatibility and sizing

This flashing is specifically engineered for VELUX rooflights and skylights and is not suitable for other window manufacturers. The product is available in two lengths: 78cm and 140cm. It is compatible with various timber grades including softwoods and hardwoods, and is rated for use in walls up to 2.4m high. Check your VELUX window specification and wall height before ordering to ensure correct sizing.

• Designed exclusively for VELUX rooflights and skylights
• Available in 78cm and 140cm lengths
• Compatible with softwood and hardwood timber frames
• Maximum wall height rating: 2.4m

Materials and durability

The flashing frame is manufactured from galvanized steel, which provides excellent corrosion resistance and extends the service life of the product in exposed roof and wall positions. The galvanized coating protects against rust and weathering. The integrated weather-resistant membrane provides an additional barrier against water ingress, working in conjunction with the steel frame to create a comprehensive weather seal.

• Galvanized steel frame resists corrosion
• Weather-resistant membrane for enhanced water protection
• Durable construction suitable for long-term external exposure

Pre-installation checks and preparation

Before fixing, verify that you have the correct VELUX flashing type for your specific rooflights or skylights model. Measure your wall height to confirm it does not exceed 2.4m. Inspect the timber frame around the opening to ensure it is sound, dry, and free from rot or damage. Check that the opening dimensions match the flashing size you have ordered. Have all fixings and sealants ready before beginning installation, and ensure the weather forecast shows dry conditions for the duration of the work.

• Confirm flashing compatibility with your VELUX window model
• Verify wall height does not exceed 2.4m
• Inspect timber frame for rot, damage, or moisture
• Check opening dimensions match flashing size
• Prepare fixings and weather-resistant sealants in advance