Chapter 1: Is the chimney on our house next to a thatched cottage in Silchester safe to leave?
What we find
A chimney on or beside a thatched roof carries more responsibility than most, because a spark or a failing flue lining matters more near straw. The stack is also the part of the house most open to wind and rain. Brick that is 200 or 300 years old can crumble, mortar joints open and the flaunching, which is the mortar shoulder bedding the pots at the top of the stack, cracks, letting water run down inside the brickwork.
From the garden you may see a lean in the stack, a pot with a crack across it, or white salt stains on the brick below the top. In the loft, look for damp patches on the chimney breast and a dark stain on the timbers beside it. Flashings at the base are the other usual leak point, and soakers (little lead tabs woven into the courses) often fail first.
What we fix
We inspect the stack from the roof, photograph each face and report what we find, before anyone talks about rebuilding. Often the answer is repointing in lime mortar, a new flaunching, replaced pots and renewed lead flashings. Lime lets the old brick breathe and give before the brick does, where cement would lock moisture in and flake the faces off. A rebuild is only needed when the brick itself has gone or the stack leans out of true.
UK cost guides put repointing a stack at £450 to £1,200 and chimney repairs generally at £500 to £2,000, and we fix our own price once we have seen the building. For the flue and any thatch-related questions, we suggest you take advice from the thatcher and a chimney sweep, and we work around them. Our chimney repairs page sets out the work.