Fixing and buying guide

What this product is and who needs it

This recessed flashing is a roof sealing component that sits flush into the eaves around roof penetrations. It is designed for builders, roofers and serious DIY customers installing or replacing skylights, roof vents or chimney flashings on residential and commercial properties. The flashing prevents water ingress at vulnerable points where roof structures meet external fixtures.

Compatibility and timber requirements

The MK04 flashing is compatible with timber grades F16 and above only. Before ordering, verify your roof timber specification—typically found in building plans or structural documentation. If your timber grade is below F16, this product is not suitable and you must source an alternative. The flashing works on both pitched and flat roof applications.

• Check roof timber grade specification before purchase
• Suitable for F16 timber and higher grades only
• Compatible with pitched and flat roof constructions
• Designed for installation around chimneys, skylights and roof vents

Size and pack contents

This is a single recessed flashing unit measuring 78 × 98cm (product code MK04). One unit covers one roof penetration of this size. If you have multiple penetrations or larger openings, you may need to order additional units or consider alternative flashing sizes. Confirm the dimensions of your roof opening match this specification before purchasing.

Pre-installation checks

Before fixing, inspect the flashing for any damage and ensure your roof structure is sound and dry. Verify that the timber grade is F16 or above and that the opening dimensions match the 78 × 98cm flashing size. Check that the roof surface is clean and free from debris. Have appropriate fixings and roofing sealant to hand—these are not included with the flashing itself.

• Confirm timber grade is F16 or higher
• Measure roof opening to ensure it matches 78 × 98cm dimensions
• Inspect flashing for transport damage
• Ensure roof surface is clean and dry before installation
• Source compatible fixings and weather-resistant sealant separately