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Project Duration
This lead bay window replacement was completed by our team in around 4 days.
Project Location
Leadwork Services
The Lead Lads provide specialist leadwork services for bay windows, flashings, gutters, valleys and traditional roof details.
Leadwork Project Details | The Lead Lads ®
The Property
Lead Bay Window Replacement – Harrogate, North Yorkshire
This project involved the like-for-like replacement of lead bay window roof coverings to a large double-fronted property overlooking The Stray in Harrogate. The bay windows form a key part of the principal elevation, sitting either side of the central entrance and adding important character to the front of the house.
Lead bay windows are highly visible architectural details, so care needs to be taken when replacing the roof coverings. The new leadwork needed to protect the bay structures, improve the appearance of the frontage and sit neatly with the existing stonework, window frames and masonry abutments.
The timber substrate beneath the new lead sheets had already been replaced, allowing The Lead Lads to focus on forming the new Code 5 lead bay coverings, timber roll details, abutment flashings and sealed masonry chases.
Why the Original Leadwork Needed Replacing
The original bay roof coverings had reached the end of their useful service life and were removed before the new leadwork was installed. Older bay roofs can fail through age, fatigue, movement stress, weak abutment details, poor fixing methods or deterioration of the support beneath the lead.
On prominent front elevations like this, replacement is not only about stopping water ingress. It also protects kerb appeal, preserves the symmetry of the property and ensures the lead details remain visually appropriate for a traditional Harrogate home.
Leadwork Standards and Technical Approach
This project was completed using a standards-led approach focused on correct lead bay sizing, timber roll formation, secure clipping and proper abutment weathering.
- BS 6915 informed the design and installation of the fully supported lead sheet coverings.
- BS EN 12588 governed the rolled lead sheet material specification.
- Lead Sheet Association guidance informed bay sizing, fixing principles, bossing, roll detailing, flashings and movement allowance.
The key principle was to divide each roof into correctly detailed bays so that the lead could move naturally. New timber rolls were installed to create five distinct bays to each roof area, with the Code 5 lead bossed around the rolls and secured using suitable clips.
Contact us about leadwork More leadwork resources and guides The leadwork LinkSpecification of Works
Preparation and Removal
- Access scaffolding erected to both bay window roof areas.
- Existing lead coverings removed from each bay roof.
- Removed lead set aside for recycling by the client.
- Existing substrates checked before new leadwork installation.
- Bay roofs set out for timber rolls, building paper and Code 5 lead coverings.
Substrate and Support
- Previously renewed timber substrate checked for suitability.
- Building paper installed beneath the new lead sheet coverings.
- New wood core rolls installed to form five distinct bays to each roof area.
- Abutment areas prepared ready for new Code 5 lead flashings.
Leadwork Installation
- New bay roof coverings formed using Code 5 rolled lead sheet.
- Lead bays set out to suit the dimensions and symmetry of each bay window.
- Lead formed around the timber rolls using traditional bossing methods.
- Stainless steel clips installed to secure the lead without restricting movement.
- Front and side edges dressed neatly to provide clean weathering.
- New Code 5 lead abutment flashings fitted against the masonry.
- Chases pointed with suitable lead mastic to complete the weathering detail.
- Finished leadwork checked for neatness, laps, movement allowance and visual consistency.
Finishing and Protection
- Completed bays inspected for alignment and finish.
- Masonry chase seals checked for continuity.
- Finished leadwork cleaned down and checked before handover.
The Materials
This project used a focused set of traditional leadwork materials selected to provide durable and visually sympathetic bay window coverings.
- Code 5 lead
- Building paper
- Stainless steel clips
- Wood core rolls
- Lead Sealant
- Patination oil where required
If you are trying to understand which code of lead is right for a similar detail, our shoppable lead chart is a useful starting point. For broader product learning, see The Lead Handbook and our lead roofing guides.
The Lead & Materials Used By Us 🛒 Lead Weight Calculator
Skills Required
- lead bossing
- lead welding
- forming timber rolls
- basic joinery
- lead flashing
- mastic sealing to masonry joints
What This Project Teaches About Lead Bay Windows
Lead bay window roofs are small roof areas, but they play a major role in both weather protection and appearance. On a double-fronted property like this, the two bays need to be detailed consistently so that the finished elevation looks balanced and well maintained.
This project shows why timber rolls, correct bay sizing, suitable clips and properly sealed abutment flashings all matter. The leadwork must be secure, but it must also be free to move naturally as temperatures change. That balance is what gives traditional lead bay roofs their durability.
Property Owner Takeaways
- Lead bay roofs help protect both the window structure and the property’s front elevation.
- Like-for-like replacement can improve performance while preserving traditional appearance.
- Code 5 lead, building paper and timber rolls are a strong combination for bay window details.
- Abutment flashings and chase sealing are essential to keep water out at the masonry junction.
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 is used for bay window roofs?
Code 5 lead is commonly used for many lead bay window roof coverings, depending on the size and detailing.
Why are timber rolls used on lead bay roofs?
Timber rolls divide the roof into bays, help manage movement and create a traditional raised joint detail.
Why is building paper used beneath lead?
Building paper separates the lead from the substrate and helps reduce abrasion as the lead moves.
What causes lead bay roofs to fail?
Common causes include age, poor fixing, weak abutments, failed substrate, restricted movement and poor detailing.
Can old lead be recycled?
Yes. Removed lead can usually be recycled, as was done by the client on this project.
Where can I buy lead bay roof materials?
You can explore lead roll, building paper, fixings and leadwork guides through the Lead Lads Shop.
