GNR Roofing Services
Leadwork Contractors
Specialist leadwork contractors based in York, working across Yorkshire and the North of England. We undertake lead roofs, bay windows, gutters, valleys, dormers, flashings and complex roof interfaces using experienced in-house leadworkers.
Our leadwork is planned around the building, substrate, lead code, panel dimensions, thermal movement, drainage and applicable BS 6915 and industry guidance.
Specialist Roofing Discipline
What Is Leadwork?
Leadwork is the use of formed lead sheet to provide durable weathering, drainage and roof coverings. It is commonly used around chimneys and abutments, within valleys and gutters, over bay windows and dormers, and as a complete covering to roofs and architectural features.
Lead is highly durable and can accommodate complex building shapes. However, its performance depends on correct design. The selected lead code, sheet dimensions, laps, fixings, substrate and joint arrangement must allow the material to expand and contract without becoming restrained.
Incorrectly sized or over-fixed lead sheets can split, distort or fatigue prematurely. Successful installation therefore requires more than simply dressing the material into position.
GNR undertakes leadwork with reference to BS 6915, BS EN 12588, relevant manufacturer information and established lead-sheet working guidance.
Read Our BS 6915 Guide View Leadwork Projects
Specialist Leadwork Services
Our employed leadworkers undertake projects ranging from individual flashings and bay-window roofs to substantial gutters, dormers and complete lead roof coverings.
Lead Roof Coverings
Complete pitched and low-pitched lead roofs, canopies, dormer tops and architectural coverings formed in appropriately sized bays with suitable joints, falls and perimeter weatherings.
Lead Gutters
Box gutters, parapet gutters, valley gutters and perimeter linings, including steps, outlets, sumps, overflows, welded details and interfaces with adjoining roof coverings.
Lead Valleys
Replacement and installation of lead valley linings, including examination of the supporting structure, gutter base, laps, roof pitch and connection with slate or tiled roof coverings.
Lead Bay Roofs
Bay-window roofs formed using flat panels, wood-cored rolls, welts or welded details according to the roof shape, dimensions, drainage and architectural character.
Lead Bay Roof ServiceChimney Flashings
Aprons, back gutters, step flashings, cover flashings and soakers installed around chimneys, walls and roof abutments as part of repair or complete re-roofing work.
Dormers and Cladding
Lead dormer cheeks, roofs, aprons, cills, facings and complex window interfaces formed to accommodate thermal movement while maintaining a coherent architectural finish.
Lead Hips and Ridges
Traditional lead hip and ridge weatherings formed over suitable timber rolls and detailed to integrate correctly with natural slate and compatible flat-profile roof coverings.
Lead Welding
Welded outlets, sumps, corners, penetrations, patches and bespoke details where bossing alone would compromise the material or cannot produce the required shape.
Heritage Leadwork
Traditional and conservation-sensitive leadwork for listed buildings, churches, period properties and historically important roofs, including sandcast lead where required by the project.
Lead Hips
Durable traditional weatherings for slate and flat-profile roofs.
Lead Dormers
Roofs, cheeks, flashings and interfaces formed as one system.
Complex Detailing
Purpose-made lead details formed for the building and roof geometry.
Roof Interfaces
Weathering and rainwater management at vulnerable junctions.
Lead Roofs
Complete coverings designed around movement, falls and drainage.
Heritage Leadwork
Traditional material knowledge supported by modern project control.
Leadwork Begins Beneath the Lead
The quality of a lead roof depends heavily on the construction beneath it. Damaged decking, insufficient falls, unsuitable insulation arrangements or poorly designed ventilation cannot be corrected simply by installing new lead over the top.
Where required, GNR can undertake the complete package, including:
- Removal of existing coverings
- Inspection of concealed construction
- Timber and structural repairs
- Formation of falls and steps
- Plywood or suitable supporting decks
- Vapour-control layers
- Insulation and thermal upgrades
- Ventilation paths and openings
- Lead underlay and separating layers
- Timber rolls, drips and perimeter details
- Final lead-sheet covering and flashings
This reduces the risk of one contractor forming the substrate and another attempting to adapt the leadwork to unsuitable construction.
Warm and Cold Roof Construction
Warm Roof Build-Up
In a warm-roof arrangement, insulation is positioned above the principal structural deck. A correctly detailed vapour-control layer and continuous insulation help keep the structure warmer and reduce the risk of interstitial condensation.
Cold Ventilated Build-Up
In a cold-roof arrangement, insulation is positioned below a ventilated cavity. The cavity requires a suitable and continuous airflow path, normally with correctly positioned inlet and outlet ventilation.
The appropriate solution depends on the building, existing construction, roof geometry, thermal requirements and feasibility of forming the necessary details. Neither arrangement should be selected without considering moisture movement through the complete roof build-up.
Discuss a Lead Roof Build-UpLeadwork Designed to Accommodate Movement
Lead expands and contracts in response to temperature. The principal purpose of bay sizes, laps, welts, rolls, steps and fixing patterns is to permit that movement without allowing the material to become overstressed.
Before installing leadwork, we consider:
- The lead code and sheet thickness
- The maximum panel or strip dimensions
- The pitch and orientation of the roof
- Expected solar exposure
- Falls and drainage paths
- Mechanical joints and welded details
- Fixing positions and materials
- Upstands, laps and cover dimensions
- Compatibility with adjoining materials
- Maintenance and safe access requirements
A heavier lead code does not automatically make an installation better. The selected material must be appropriate for the application and formed within the relevant dimensional guidance.
Standards and Guidance
Lead-sheet installation may draw upon several standards and sources of guidance, including:
- BS EN 12588 for rolled lead-sheet specification
- BS 6915 for design and installation principles
- Industry training and technical guidance for practical lead-sheet detailing
- BS 5250 principles for moisture management
- Project-specific architectural and conservation requirements
- Relevant manufacturer guidance for insulation, membranes and adjoining roof systems
Standards provide essential parameters, but the installer must still understand the existing building and determine how the leadwork will interact with the structure, roof covering and drainage system.
View Leadwork Regulations Technical Leadwork GuidesLead Codes: Quick Reference
Rolled lead sheet is supplied in numbered codes. The code identifies its nominal thickness and weight. Application, dimensions and detailing must be considered together rather than choosing the material solely by thickness.
| Code | Nominal thickness | Common applications |
|---|---|---|
| Code 3 | 1.32 mm | Soakers and concealed weathering details where appropriately protected |
| Code 4 | 1.80 mm | Aprons, cover flashings, stepped flashings and general weatherings |
| Code 5 | 2.24 mm | Valleys, gutters, dormer cheeks, vertical cladding and selected roof coverings |
| Code 6 | 2.65 mm | Bay roofs, dormer roofs, gutters and more demanding exposed applications |
| Codes 7–8 | 3.15–3.55 mm | Heavy-duty roof coverings, gutters and specialist heritage applications |
The table is an introductory guide only. The correct code, bay size, joint arrangement and fixing method must be determined for the individual application.
Order Rolled Lead Sheet Lead Codes Technical GuideDomestic and Heritage Leadwork
Leadwork to Bay Windows
Lead is particularly well suited to bay-window roofs. It provides a traditional finish, can be formed around straight or curved building geometry and can accommodate roof abutments, window interfaces and perimeter drainage within a relatively small area.
A bay roof may appear simple, but its performance depends on several connected elements:
- Condition and strength of the supporting structure
- Suitable falls toward the drainage edge
- Correct roof build-up and moisture control
- Appropriate lead code and panel dimensions
- Wood-cored rolls, welts or flat-panel joints
- Drips and leading-edge detailing
- Wall upstands and cover flashings
- Interfaces with adjoining slate or tile roofs
- Allowances for thermal movement
GNR can undertake the complete replacement, including opening the existing roof, repairing the substrate, improving the build-up and installing the new lead covering and associated flashings.
Lead Bay Roof Service Request a Bay Roof Assessment
Lead Bays
Panel layouts and rolls formed to permit thermal movement.
Long-Term Performance
Durable leadwork supported by correct substrate construction.
Gutters and Abutments
Integrated drainage and weathering at vulnerable roof junctions.
Curved Bays
Traditional leadwork formed around circular building geometry.
Intricate Roof Areas
Careful detailing where several materials and interfaces converge.
Traditional Details
Clips, tabs, welts, rolls, flashings and welded junctions.
GNR Roofing Services
Why Choose GNR for Leadwork?
Leadwork is a specialist roofing discipline requiring trained operatives, suitable tools and a practical understanding of how the material moves and performs.
Our leadwork is undertaken using our own employed teams. This gives us greater control over substrate preparation, panel setting-out, lead welding, sequencing and integration with adjoining roof areas.
- Established roofing contractor since 1981
- Experienced employed leadworkers
- Lead welding and specialist detailing capability
- In-house roofing and joinery support
- Complete projects from substrate to final covering
- Residential, commercial and heritage experience
- NFRC membership and heritage capability
- Project-specific scopes and quotations
Indicative Leadwork Costs
Leadwork quotations depend on the dimensions, lead code, access, supporting construction and complexity of the interfaces. Initial budget ranges may include:
- Chimney flashings: commonly from £350–£650 for limited straightforward work
- Lead valley renewal: commonly from £650–£1,200 per valley
- Bay-window lead roofs: commonly from £650–£2,200+
- Larger gutters and complete lead roofs: individually assessed
Figures are indicative only and may exclude scaffolding, structural repairs, substantial joinery, insulation upgrades, removal costs and associated roof work.
Request Project GuidanceWhat Affects the Price?
- Scaffolding and access requirements
- Area and geometry of the leadwork
- Selected lead code
- Condition of timber and supporting decks
- Warm-roof or ventilated construction requirements
- Number of bays, rolls, welts and steps
- Welded outlets and complex junctions
- Interfaces with chimneys, walls, slate and tiles
- Heritage or conservation requirements
- Removal, recycling and protection of surrounding finishes
Photographs and dimensions can sometimes support an initial budget indication. A structured inspection may be required where the construction is concealed or the cause of failure is uncertain.
Leadwork Contractors Across Yorkshire
GNR Roofing Services is based in York and undertakes specialist leadwork throughout Yorkshire and the wider North of England.
Our regular working areas include York, Harrogate, Leeds, Wetherby, Selby, Malton, Ripon, Thirsk, Scarborough, Knaresborough and surrounding parts of North, West and East Yorkshire.
For substantial lead roofs, heritage projects, specialist gutters and technically demanding work, we are also happy to consider projects further afield.
Suitable Projects Include
- Domestic bay-window replacements
- Complete lead roof coverings
- Heritage and listed-building leadwork
- Churches and ecclesiastical buildings
- Large gutters and parapets
- Dormers and architectural features
- Leadwork incorporated into complete re-roofing
- Defective or prematurely failed installations
Leadwork Frequently Asked Questions
Common questions about lead codes, roof construction, surveys and leadwork durability.
Which code of lead should be used?
The appropriate code depends on the application, panel dimensions, exposure and joint arrangement. Code 4 is widely used for flashings, Code 5 for many valleys and gutters, and Code 5 or Code 6 for numerous bay-roof applications. Code selection should always be considered alongside the relevant dimensional guidance.
Is a warm or cold roof better beneath leadwork?
Both can perform when correctly designed. Warm-roof construction places insulation above the principal deck and can simplify condensation control. Cold-roof construction requires an effective and continuous ventilation path beneath the supporting deck. The correct arrangement depends on the existing building and project constraints.
How long should leadwork last?
Properly designed and installed leadwork can last for many decades. Its life is influenced by sheet dimensions, thermal movement, lead code, substrate condition, falls, drainage, atmospheric exposure and the quality of the installation.
Can split leadwork be repaired?
Localised welding repairs may be possible in some circumstances. However, splitting often indicates that the original sheets were restrained, incorrectly sized or subject to repeated fatigue. The underlying cause should be investigated before deciding whether repair or replacement is appropriate.
Does GNR undertake the timberwork beneath lead roofs?
Yes. GNR can undertake supporting joinery, deck replacement, formation of falls, timber rolls, insulation, vapour-control layers and associated roof work as part of a complete leadwork package.
Does GNR supply lead materials?
Lead sheet, fixings, underlay, patination oil and related accessories are available through The Lead Lads Shop. GNR provides installation and complete project delivery.
Does GNR undertake heritage leadwork?
Yes. We undertake leadwork to churches, listed buildings, period properties and conservation-sensitive roofs. This can include traditional detailing and sandcast lead where specified and appropriate.
Planning a Leadwork Project?
Send us photographs, drawings, dimensions, survey information or a description of the defective leadwork. We will review the information and advise whether the next step should be preliminary guidance, a structured inspection or preparation of a project quotation.