Lead does a lot of work on a traditional roof for how little of it you actually see. On Hammersmith’s Victorian and Edwardian housing stock, it’s almost always the flashing, not the tiles, that fails first. That makes leadwork one of the most common repairs we’re called out for.
What lead flashing actually does
Flashing bridges the join between a roof surface and anything that interrupts it. Think a chimney stack, a party wall, a dormer cheek, or a valley where two roof slopes meet. Tiles and slates shed water reasonably well on their own. But at every junction, the roof needs a flexible, weatherproof material dressed into the joint to keep water out. Lead has been the standard material for this for centuries. It’s soft enough to dress tightly around odd shapes. It also lasts for decades once it’s installed properly.
Why lead fails
Lead itself is extremely long-lasting. But the way it’s fixed and dressed matters enormously. So older lead flashing can come loose from its fixings over time. This happens most around chimneys, where thermal movement in the brickwork works the lead free at the joint. Also, poor original workmanship tends to fail years before well-installed lead would. That means flashing that wasn’t dressed tightly into the brick, or wasn’t lapped correctly at a valley. Once a section lifts even slightly, water finds the gap immediately. Because the fault sits at a junction rather than an open roof surface, the resulting leak often shows up some distance away inside the house.
Common leadwork problem areas
Chimney flashing is the single most common source of leadwork leaks we see. That’s because a chimney stack moves independently of the roof around it, which puts real strain on the joint over time. Similarly, valley leadwork is another frequent failure point — it carries more water than any other part of the roof, and any gap there floods immediately during heavy rain. Lead around dormer cheeks, and abutments where an extension roof meets the main house wall, are the other spots worth checking on any pre-purchase or condition survey.
Repair versus full re-leading
A single failed section of flashing, such as one chimney, can usually be repaired in isolation without disturbing the rest of the roof. But where multiple areas show signs of lifting, or the original leadwork is decades old and clearly near the end of its working life, full re-leading of the affected areas is the more sensible long-term approach. Patching failing lead in several places tends to become a repeated job rather than a one-off fix.
Copper and zinc: the modern alternatives
Copper and zinc roofing and flashing have become more common on contemporary extensions, particularly where a client wants a distinct architectural finish rather than traditional lead grey. Both are durable metal roofing options in their own right. Each weathers to a distinctive patina over time too — copper to a green verdigris, zinc to a matte grey. They’re a different aesthetic choice to lead, not a straight upgrade, and we’re happy to talk through which suits a particular extension design.
What we check on a leadwork inspection
On every leadwork inspection across Hammersmith, Fulham and Chelsea, we check every chimney, valley and abutment on the roof, not just the area reported as leaking. If one section of lead has failed from age or poor fixing, others on the same roof are often close behind. It’s the same thorough approach we bring to every leadwork job, whether it’s a single chimney repair or a full re-lead.
Suspect a leadwork problem, or planning ahead of a re-roof? Get in touch for a free inspection and an honest assessment of what needs doing now versus what can wait.