Craftsman dressing new lead flashing around a chimney base on a UK tiled roof

Leadwork and flashing specialists

Chimney flashings, valleys and soakers fitted the traditional way, by vetted local roofers who work lead properly.

Quick answer: leadwork is the lead sheeting that waterproofs the junctions on your roof: flashings, valleys, soakers and bay tops. Renewing the lead flashing around a typical chimney costs £300 – £800 in 2026, and properly fitted lead routinely outlasts the roof covering around it.

Leadwork specialists renew and repair the lead detailing that seals every junction on a roof. Tiles and slates shed water down the slopes, but wherever the roof meets something else, a chimney, a wall, another roof plane, a dormer, it is lead that keeps the water out. That is why so many "roof leaks" are really leadwork failures, and why leaks that only appear in heavy or wind-driven rain so often trace back to a flashing.

What leadwork covers

Chimney flashings: the apron at the front of the stack, step flashings up the sides and a back gutter behind. This is the most common leadwork job on UK homes.
Abutment and step flashing: where a roof meets a wall, such as an extension or porch roof running into the house.
Lead valleys: the channels where two roof slopes meet, which carry more running water than any other part of the roof.
Soakers: small lead pieces interleaved with tiles or slates alongside walls and chimneys, hidden under the step flashing.
Bay tops, dormers and porches: small lead-covered roofs where the sheet itself is the covering, not just the seal.

Code weights: the basics

Lead sheet is graded by thickness into code weights, and matching the code to the job is what separates leadwork that lasts decades from leadwork that splits early. As a rule of thumb, Code 3 is used for soakers, Code 4 is the standard for flashings and aprons, and Code 5 or heavier suits valleys, back gutters and anything that carries running water. Each piece also has a maximum length: lead expands and contracts with temperature, so oversized pieces fatigue and crack. If a quote does not mention code weights at all, ask why.

When you need a leadwork specialist

A damp patch on the chimney breast, especially one that appears after driving rain.
Flashing that has visibly cracked, split, or lifted away from the mortar joint.
Mortar fillets used instead of lead, common on older houses, which crack and fall away.
Previous "repairs" in sealant or self-adhesive flashing tape that have started weeping again.
A re-roof or chimney repair, when renewing the leadwork while access is up is the cheapest it will ever be.

How the job is done

A proper leadwork job follows the same sequence every time. The old lead or failed fillet is stripped out and the masonry joint raked clean. New lead is cut to length, dressed to the profile of the tiles or slates with dressing tools rather than forced flat, and turned at least 25mm into the mortar joint. It is then fixed with lead wedges, pointed or sealed, and finished with patination oil so it weathers evenly. Good leadwork looks unhurried and neat; bad leadwork looks stretched, flat and smeared with sealant.

What leadwork costs

Chimney flashing renewal is the benchmark job at £300 – £800, covered in detail in our chimney repair cost guide. Valleys, bay tops and larger details vary too much in length, code weight and access to carry a standard price, so they are priced on inspection. The honest way to budget is to get two or three itemised quotes and compare what each roofer proposes to strip, renew and guarantee.

Worth knowing: if scaffolding is going up for any other roof or chimney work, price the leadwork at the same time. Access is a big share of the bill on small lead jobs, and doing it alongside other work means you only pay for it once.

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Leadwork FAQs

Leadwork and flashing questions, answered

Renewing the lead flashing around a typical chimney costs £300 to £800 in 2026, depending on the size of the stack, the roof pitch and access. Larger leadwork jobs such as full valleys or bay tops are priced on inspection, because the length, code weight and detailing vary so much between roofs. See the chimney repair cost guide for the full breakdown.

Correctly specified and fitted leadwork routinely outlasts the roof covering around it, which is why it remains the benchmark flashing material. Failures are almost always down to workmanship rather than the lead itself: pieces cut too long so they fatigue and split, the wrong code weight for the job, or flashings pushed into shallow mortar joints without proper fixing.

Lead sheet is graded by thickness into codes, and each code suits different jobs. Code 3 is the lightest commonly used and is typical for soakers. Code 4 is the standard for chimney flashings, aprons and step flashings. Code 5 and above are used for valleys, back gutters and details that carry running water. Using too light a code for the job is a common cause of early splitting.

The junction between the chimney and the roof is sealed by lead flashings, and they fail more often than the surrounding tiles. Cracked, lifted or poorly fitted flashing lets water track down the stack and show up as a damp patch on the chimney breast, often only during heavy or wind-driven rain. A leadwork specialist can usually renew chimney flashings in a day once access is up.

Sometimes. A single split can be patch-welded and a lifted flashing can be re-wedged and repointed, which is a sensible fix on otherwise sound lead. Repeated repairs with sealant or flashing tape are a false economy though: they buy months, not years, and the labour and access costs are similar to doing the job properly.