Recognise when leadwork is the likely repair route
Leadwork protects roof junctions and channels concentrated water. Relevant details include chimney flashings and soakers, valleys, abutments, parapet or box gutters, dormers, bay roofs, ridges, hips and outlets. Splits, lifted edges, staining and repeated sealant justify assessment but do not prove one cause.
Water can bypass sound lead through masonry, slate or tile, blocked drainage or adjoining membrane. Record when the leak appears and which rain direction exposes it. Loose material, an overflowing gutter or active entry may need urgent review, subject to conditions and access.
Diagnose movement, support and water flow
Identify the lead detail and follow water from catchment to discharge. Check splits, ripples, sagging, lifted edges, weak laps, failed fixings, punctures and restrained expansion. Sheet size, joints and substrate shape help explain fatigue.
Support and adjoining materials matter as much as visible metal. Damp boarding, masonry movement, failed chases, incompatible fixings or outlet debris can undermine repair. Concealed substrate may need careful opening-up, so separate likely causes from confirmed defects.
Choose a repair that addresses the cause of the split
A local defect may suit a designed patch, weld or section repair where surrounding lead, support and layout remain serviceable. Redressing or refixing may suit a moved edge without broader fatigue. Sealant can obscure defects and restrict movement, so is not a default permanent specification.
Section renewal may fit damage at a joint, fixing or local substrate. Wider renewal becomes relevant where fatigue, poor falls, weak support or unsuitable layout recur. The scope should say what remains, how movement is accommodated and which adjoining work is needed.
Specify the detail without relying on a generic lead code
Thickness is only one part of a lead specification. Width, length, exposure, fall, joint spacing, fixing, support and movement shape the choice. Flashings, valleys and parapet gutters perform different jobs, so a material label cannot replace a clear detail.
Show how upstands, laps, edges and outlets meet surrounding construction and where water goes if an outlet blocks. Dimensions and materials need measured context. Traditional profiles and visual character may also need retention or agreement.
Coordinate masonry, slate, tile and membrane junctions
Chimney and wall flashings depend on masonry chases, pointing, soakers and the covering. Valleys depend on slate or tile edges, support and discharge. Parapet gutters connect cappings and outlets, so a narrow patch is incomplete where blockage or poor falls caused failure.
Lead also meets flat membranes, roof windows and dormers. Name each interface and any roofing, masonry, drainage or joinery preparation. For historic roofs, use the heritage leadwork route to consider compatible material and conservation context.
Plan access, protection and any hot-work decision
Valleys, parapets and chimneys can make access more complex than the visible repair suggests. Height, pitch, fragile covering, gutter depth, public space and material handling affect the plan. Assess access for the task rather than from one photograph.
If a method could involve heat, fire risk, combustible construction, occupied spaces and monitoring need separate planning. Protect rainwater routes and areas below. Share safe photographs, leak history, building use, previous patches and access restrictions.
Turn the leadwork findings into a buildable scope
Name the lead element, catchment and discharge, map defects, distinguish movement from puncture or adjoining failure, and state concealed areas. Compare repair and renewal where credible, record substrate assumptions, and identify connected masonry, covering, membrane or outlet work.
Use heritage leadwork where protected fabric and established profiles are central. Share the required output and constraints when making contact. Exact specification, safe access, material availability and timing then need confirmation from the measured detail.
