The Lead Lads
Lead Flat Roofs
Lead flat roof design, supply and installation using rolled lead sheet, correct bay sizing, warm and cold roof build-ups and proper leadwork detailing.
#properleadwork
Lead Flat Roof Coverings
Lead offers exceptional longevity, weathering performance and architectural quality when the build-up, bay sizes and details are correct.
At The Lead Lads, we design and install lead flat roofs using rolled lead sheet, correct substrate preparation, appropriate lead code selection and movement detailing aligned with recognised leadwork practice.
We consider two principal build-ups for flat lead roofs: warm roof construction and cold vented roof construction. The right choice depends on the existing structure, insulation strategy, condensation risk, drainage requirements and the wider building fabric.
Warm Roof Construction
Sub-deck → sealed vapour control layer → insulation above deck → top deck → building paper underlay or suitable separation layer → rolled lead sheet. This approach can reduce interstitial condensation risk when detailed correctly.
Cold Vented Roof Construction
Lead on a supported deck with insulation below and a continuous ventilated void. Ventilation paths must be clear, balanced and unobstructed from inlet to outlet.
Our detailing is informed by BS 6915:2001+A1:2014, BS 6229 substrate principles, BS EN 12588 rolled lead sheet and LSTA guidance.
For material support, clients and contractors can also browse rolled lead sheet, the lead chart, the lead weight calculator and leadwork fixings.
Say Hello
Warm Lead Roof
Insulation above the structure with a sealed vapour control layer below. This can reduce moisture risk when combined with correct bay sizing, substrate design and movement joints.
Which Code Lead?
Code selection reflects bay size, exposure, pitch and support. For lead flat roofs, Code 5 to Code 8 may be considered depending on the detail.
Stepped Lead Roof
Work within practical bay lengths and movement limits. Use wood rolls, king rolls, steps, drips or welded details where specified to control thermal movement.
Ventilation Details
Cold roofs require continuous and balanced ventilation from inlet to outlet. Warm roofs rely on correct vapour control and layer design instead.
Vented Lead Roof
Maintain a clear air path with unobstructed flow. Movement in linings, edges and cover flashings must be considered to avoid restraint.
Rainwater Management
We design and form lead-lined gutters, drips, sumps, outlets and overflows. Correct falls and outlet coordination are critical to performance.
Lead Flat Roof Essentials
A quick reference to the core decisions that help a lead flat roof perform properly.
Bay sizes, joints and movement
Individual bay dimensions should be controlled by code, exposure, pitch and practical guidance. Wood rolls, king rolls, welts, drips and welded joints may all be used to manage movement. Edges should not be hard restrained.
Substrates and underlays
Support must be smooth, stable and continuous. Suitable plywood or close-boarded softwood are common beneath rolled lead sheet. Building paper or suitable separation layers may be required depending on the detail. Avoid unsuitable membranes directly below lead.
Patination and finishing
Patination oil is commonly applied to exposed faces during installation to reduce early carbonate staining and run-off marks. Good water control, clean drips and proper detailing still matter most.
Warm vs cold lead roofs
Warm roofs place insulation above the deck with a sealed vapour control layer. Cold roofs require a ventilated void with clear inlets and outlets. The correct choice depends on the existing structure and condensation strategy.
Welding and bossing
Bossing may be appropriate where the lead can be formed without excessive thinning. Welding is used where corners, joints, outlets or expansion details require full-thickness integrity. Hot works controls are essential.
Gutters, outlets and overflows
Lead flat roofs often rely on properly formed outlets, sumps, drips and gutters. Rainwater design, maintenance access and overflow provision should be considered from the outset.
Lead Flat Roof Services
We deliver surveys, specification support and installation for lead flat roofs across residential, heritage and commercial projects.
Lead Flat Roof FAQs
Practical answers for clients, architects, builders and contractors.
What code of lead is best for a flat roof?
Lead flat roof code selection depends on bay size, exposure, pitch, detailing and support. Code 5 to Code 8 may be considered depending on the application. The correct code should be specified for the real roof, not chosen by habit alone.
Warm or cold lead flat roof — which should I choose?
Warm roofs place insulation above the deck with a sealed vapour control layer and can reduce condensation risk when correctly detailed. Cold roofs require ventilation and are more dependent on clear air paths. The correct choice depends on the building, budget and build-up.
How long does a lead flat roof last?
A properly designed and installed lead flat roof can offer a very long service life. Longevity depends on correct material, bay sizing, movement allowance, substrate condition, water management and maintenance.
Do I need patination oil on a lead flat roof?
Patination oil is commonly applied during installation to reduce early white carbonate staining and run-off marks. It should be used as part of a good finishing process, but it does not replace proper detailing.
Can you supply materials as well as install lead flat roofs?
Yes. Rolled lead sheet, leadwork fixings, underlay, accessories and practical tools are available through The Lead Lads Shop. Installation enquiries can be sent directly to The Lead Lads.
Which standards apply to lead flat roofs?
Lead flat roofs should be considered with reference to BS 6915 for leadwork design and installation, BS EN 12588 for rolled lead sheet material quality, BS 6229 for flat roof substrate and moisture principles, and practical LSTA guidance.
#properleadwork
Lead Flat Roof Procurement
From survey to sign-off, The Lead Lads can support the whole lead flat roof package.
We can assist with access planning, substrate preparation, compliant warm or cold roof build-ups, rolled lead sheet selection and installation in accordance with BS 6915.
Materials are available through our own Lead Shop, including rolled lead sheet, fixings, lead chart guidance and lead roofing guides.
Get in touch