Chapter one
Where flint walls meet the roof
Flint is lumpy, so a flashing against it cannot follow a neat line, and the lead needs patient dressing.
The Victoria County History, writing in 1953, found flint and brick walls in Westbourne's houses, with timber-framing and flint infill, and noted that many roofs were thatched. Flint is irregular. A roof that abuts a flint gable or a garden wall meets a face that is never quite flat, and the join is sealed with lead. Once a flashing lifts, water travels behind the wall face and turns up as a mark far from where it got in, which is why tracing comes before quoting. The wall gets inspected along with the roof, because loose pointing beside the lead, or a flint that has dropped out, gives rain a second way in, and that is easy to miss from a ladder alone.
At a glance
- Lead flashing seals roofs to walls and chimneys
- Code 4 lead is the general-purpose flashing weight
- Lead flashing can last over 80 years

1.1 Flashings, soakers and stepped lead
Flashing means lead cut and bent to cover the gap where roof and wall meet. Where a slope rises against a wall, stepped flashing follows the courses of brick or flint, while soakers, small bent pieces of lead interleaved with the tiles, carry water underneath. Leadworx describes code 3 as suited to soakers only and code 4 as the usual choice for general flashing, with code 5 for vertical and pitched work. The codes run by thickness: code 3 is 1.32 mm, code 4 is 1.80 mm and code 5 is 2.24 mm. MyJobQuote says lead flashing can last over 80 years, more for the higher codes, although poor fixing or a chimney that moves behind it will shorten that. We cut each step into a mortar joint and point it, rather than sticking lead to the face with sealant.

1.2 Chimneys and flaunching
Chimneys stand on many cottage roofs here. Flaunching is the sloping mortar collar round the base of the pots; once it cracks, rain finds its way down into the stack, and the lead where the stack leaves the roof is the next suspect. We inspect the stack from the roof or with a camera, and we photograph the flaunching, the pointing and the lead before anything is quoted. Repointing a flint-and-brick stack calls for a mortar that suits the old work. Our lead roofing and chimney repairs pages set out the options in more detail.
Typical UK costs for chimney lead
- Lead patch repair£150 to £250
- Chimney leadwork, no scaffold£350 to £460
- Chimney leadwork, with scaffold£700 to £920
- Stepped flashing per metre, ex VAT£80 to £120
Every job is priced once the survey is done, and the written total says whether VAT and scaffold are counted. Source: MyJobQuote leadwork guide, updated 22/09/26; Checkatrade roof repair guide, updated 10/26.




