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Project Duration
This lead bay window roof replacement was completed in around 3 days.
Project Location
Leadwork Services
The Lead Lads provide specialist leadwork services for bays, flashings, gutters, valleys and traditional roof details.
Leadwork Project Details | The Lead Lads ®
The Property
Lead Bay Window Roof Replacement – Wakefield
This project involved the replacement of a failed lead bay window roof to a private residential property in Wakefield. The property sits on a well-used route between Leeds and Wakefield, where traditional bay windows form an important part of the front elevation.
Bay window roofs may be small, but they are exposed and technically important. They collect rainwater from the window and masonry above, while also protecting the structure below from moisture ingress. When the lead covering, substrate or perimeter details begin to fail, staining, damp patches and timber decay can quickly follow.
For this project, the existing leadwork was stripped back and the bay was rebuilt with new support, carefully formed Code 5 leadwork, welded details, welted panels, new flashings and a properly formed outlet discharging into the existing hopper head.
Why the Original Leadwork Needed Replacing
The original bay roof covering had reached the stage where a full replacement was the most sensible option. The detail included a stone plinth, perimeter capping, flashings and outlet work, so the repair needed to address the whole weathering system rather than only the visible lead sheet.
Older bay roofs often fail because of fatigue, poor movement allowance, weak edge details, split corners, failed flashings, deteriorated timber support or ineffective drainage. Once water begins to sit on the surface or track into the structure below, patch repairs rarely provide a durable long-term solution.
Leadwork Standards and Technical Approach
This project was carried out using a standards-led approach, with close attention given to support, movement, weathering and durability.
- 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 bay sizing, fixing, welding, bossing, welting and general good practice.
The key aim was to create a lead bay roof that could shed water effectively while still allowing the lead to move naturally. This required accurate setting out, suitable support, correct fixings, welded outlet work and careful detailing to the perimeter stonework and house facade.
Contact us about leadwork More leadwork resources and guides The leadwork LinkSpecification of Works
Preparation and Removal
- Safe access established to the bay window roof area.
- Surrounding windows, masonry, stonework and facade details protected.
- Existing lead sheet coverings, flashings and fixings carefully removed.
- Old defective substrate materials stripped back where required.
- Bay roof area prepared for new support and leadwork installation.
Substrate and Support
- Exterior-grade plywood installed to form a sound base for the new covering.
- A central step was formed within the bay using plywood.
- The perimeter stone parapet was overlaid with plywood ready for new lead weathering.
- Decking, upstands and edge details prepared to suit the new leadwork layout.
Leadwork Installation
- New bay coverings formed using Code 5 rolled lead sheet.
- Welted panels installed to the perimeter of the stone plinth.
- A concealed stainless steel edge clip used to help secure the perimeter detail.
- Tabs fully welded to the vertical face of the welted panels.
- Independent welted lead capping installed around the perimeter.
- New lead flashings fitted and sealed against the facade of the house.
- A new outlet formed and welded into the leadwork.
- Outlet arranged to discharge neatly into the existing hopper head.
Finishing and Protection
- Patination oil applied to protect the new lead surface.
- Completed leadwork checked for finish, falls, joints and outlet performance.
- Work area cleaned down and left tidy on completion.
The Materials
This project used a focused selection of materials chosen to suit the bay window detail, perimeter stonework and outlet arrangement.
- Code 5 lead
- Exterior-grade plywood
- Timber rolls and formed support details
- Concealed stainless steel edge clip
- Lead-compatible sealant
- Patination oil
For guidance on lead codes, fixings and suitable materials, see The Lead Handbook, our lead roofing guides and the shoppable lead chart.
The Lead & Materials Used By Us 🛒 Lead Weight Calculator
Skills Required
- lead welding
- lead bossing
- lead dressing
- welted panels
- forming outlets and cappings
What This Project Teaches About Lead Bay Window Roofs
This project shows why a bay window roof should be treated as a complete weathering detail. The lead covering, substrate, perimeter capping, flashings and outlet all need to work together. If one element is weak, water can track into the structure and cause further damage.
The work also highlights the importance of specialist leadworking skills. Details such as welded tabs, welted panels, formed outlets and perimeter cappings require careful setting out and proper execution. When completed correctly, the result is a neat, durable and sympathetic lead roof that suits the character of the property.
Property Owner Takeaways
- Lead bay roofs often fail because of poor support, weak joints, defective flashings or restricted movement.
- Stone plinths and perimeter details need proper weathering, not just a replacement sheet over the top.
- Welded outlets and welted cappings can provide a clean and durable finish when correctly formed.
- Using a specialist leadwork contractor helps ensure the bay roof performs as well as it looks.
Related Lead Lads Resources
- Lead roofing projects
- Leadwork standards hub
- Leadwork services
- Shoppable lead chart
- Lead roll
- Leadwork fixings
Frequently Asked Questions
What code of lead was used on this bay window roof?
This project used Code 5 lead, which is commonly used for many traditional bay roof details where a robust, fully supported covering is required.
Why do lead bay window roofs fail?
Common causes include age, poor movement allowance, failed flashings, weak perimeter details, split joints, poor drainage and defective timber support below the lead.
Why was plywood used below the lead?
Plywood provides a smooth, continuous and stable support for the lead covering, helping the finished roof perform correctly.
Why was a new outlet formed?
The outlet was needed to manage rainwater and discharge it into the existing hopper head, reducing the risk of ponding and water ingress.
Do bay window roofs need specialist leadwork?
Yes. Bay roofs often include small but complex details such as cappings, welded joints, drips, flashings and outlets.
Can The Lead Lads replace similar lead bay roofs?
Yes. The Lead Lads replace and restore lead bay roofs, flashings, gutters, valleys and traditional roof details across a range of property types.
