Chapter 1: Who deals with the leaking lead around the shared chimney on our Victorian terrace in Knaphill?
What we find
On a terrace, the chimney stack often sits on the party wall and serves both houses. That makes it a shared structure, and its flashings run across both roofs. Lead flashings wear out through years of heating and cooling, the soakers (small lead pieces interleaved with slates up each side of the stack) corrode at the edges, and the mortar holding the lead into the brickwork falls out. A weakness on one side lets water into the other house first.
The signs are ceiling stains next to the chimney breast, damp on the party wall, peeling paint beside the flue and, in the loft, wet timber near the stack. Neighbours often report the problem before the owner sees it. Because the roof line runs unbroken along the terrace, a leak on one slope can wet more than one property.
What we fix
We start with a conversation with you about whether your neighbour is willing to deal with the stack at the same time, because a shared stack is usually cheaper and tidier to repair in one visit. Our photograph survey of the stack and the lead gives both of you the same evidence. We then replace the flashings and soakers with new lead, repoint in a lime mortar if the bricks are old, and check the pots and flaunching.
A typical UK range for replacing chimney leadwork is £350 to £920, scaffolding extra. Where slates around the stack are slipping, we replace those too. Related reading: soakers and step flashing and our chimney repairs page.