The Property

Curved Lead Bay Window – York, North Yorkshire

At Rathbone House, 292 Tadcaster Road, York, our team carried out specialist leadwork to a curved bay window detail on a Grade II listed building formerly known as Moorlyn. Dating from around the mid-19th century, the property later saw twentieth-century alterations. Even so, its most distinctive features remain the elegant curved front bays that frame the main entrance.

Because the building is listed, every visible detail matters. In this case, the leadwork needed to do more than keep water out. It also had to protect the proportions, lines and character of the original frontage. Historic England records the architectural significance of the property here.

Although curved bay details may look decorative, they are technically demanding. Gutter linings, bay coverings, cornice details, flashings and outlets all come together in one exposed feature. As a result, success depends on both the correct materials and the skill to shape the lead neatly around curved geometry and prominent junctions.

Why the Original Leadwork Needed Replacing

Over time, the original leadwork had deteriorated to the point where renewal offered the best long-term solution. On curved bays of this kind, problems often begin in the gutter linings, outlets or joints. From there, movement, weathering and age gradually weaken the wider detail.

Just as importantly, curved bays concentrate both rainwater and visual attention. Therefore, weakness in the cappings, flashings, cornice details or outlet arrangement becomes more obvious and more serious. Rather than patch isolated areas, we renewed the leadwork properly so the bay could perform well again while still looking right on a listed frontage.

Leadwork Standards and Technical Approach

From the outset, we focused on movement, durability, neatness and long-term weathering performance.

• BS 6915 informed the design and installation of the fully supported lead sheet covering.
• BS EN 12588 governed the rolled lead sheet material specification.
• Lead Sheet Association guidance informed curved detailing, bossing, welding, roll formation and movement control.

In practice, that meant selecting the correct lead code, allowing for expansion and contraction, forming clean joints, and building reliable gutter and outlet details into the bay. Above all, curved leadwork must look right and work properly. One without the other is never enough.

Specification of Works

Preparation and Removal

• Carefully stripped back the existing lead details where renewal was required.
• Prepared the curved bay structure and surrounding support areas for new work.
• Checked abutments, cornice lines and outlet positions before installation began.
• Sequenced the works to protect the listed fabric and preserve the architectural form of the bay.

Substrate and Support

• Prepared timber support and wood core roll details to suit the curved geometry.
• Checked fixing backgrounds and supporting surfaces to ensure a sound base beneath the new leadwork.
• Set out gutter falls and outlet positions to encourage clear water discharge.

Leadwork Installation

• Installed new Code 5 lead gutter linings, including T-Pren expansion joints to help manage movement.
• Fitted new Code 5 lead flashings to the abutments and sealed them with lead-compatible sealant.
• Formed new Code 5 lead bay coverings with wood core roll details.
• Created perimeter welted capping and cornice details, complete with drip edges.
• Formed new lead outlets and connected downpipes to suit the drainage layout.
• Used lead bossing and lead welding throughout to shape the curved details neatly and accurately.

Finishing and Protection

• Applied patination oil to all newly completed leadwork.
• Checked the finished details for continuity, movement allowance and water run-off.
• Cleaned down the curved bay so the finished work sat neatly against the listed frontage.

The Materials

For this project, we selected traditional leadwork materials suited to curved bay detailing, drainage control and listed-building presentation.

• Code 5 lead
• wood core roll
• copper ringshank nails
• patination oil
• copper fixing strip
• Lead T-Pren expansion joint

If you are comparing materials for a similar curved bay or canopy detail, our shoppable lead chart is a helpful place to start. In addition, you can explore broader product guidance through The Lead Handbook and our lead roofing guides.