Chimney repairs, repointing and proper lead flashing

If you have damp on a chimney breast, or a stain on an upstairs ceiling near the stack, the roof covering is probably fine. Chimneys are where a roof gets complicated: a vertical structure punching through a sloping surface, with four different details that all have to work.

They are also the part most exposed to weather — standing proud of the roof, taking wind and rain from every direction, with mortar joints that are decades older than anything else up there.

Signs the stack is the problem

• Damp patch on the chimney breastWater tracking down inside the stack. Almost always flashing or haunching.
• White staining on the brickworkSalts washing out of saturated masonry. The stack is holding water.
• Mortar missing between the bricksRepointing needed before frost gets in and takes the bricks with it.
• The stack looks like it is leaningSulphate attack, or the mortar has failed on one side. Get this looked at promptly.
• Lead that looks white, cracked or liftedOld flashing at the end of its life, or fatigued from being cut too long.
• A cracked or missing pot, or crumbling haunchingWater going straight down the flue. Common on stacks that are no longer used.

What we do

1. Lead flashing renewalCorrect code lead, cut into the mortar course, wedged and pointed. Stepped up the sides, apron at the front, back gutter behind — each one formed properly rather than bodged with a single sheet.
2. RepointingRaking out the failed mortar to a proper depth and repointing in a mix that suits the brick. On older Cardiff stacks that often means lime rather than cement, so the brick can still breathe.
3. Partial or full rebuildWhere the brickwork has gone too far to point. Rebuilt from sound courses up, in matching brick where we can source it.
4. Re-haunching and potsNew haunching around the pot, or a cap if the flue is redundant — vented, so the stack does not sweat.
5. Removal and making goodIf the stack is redundant and you would rather be rid of it, taken down and the roof closed up properly.

What chimney work costs in Cardiff

Guide ranges for South Wales, 2026, including access for a typical two-storey house.

Access drives chimney prices more than the work itself. A stack on a gable end you can reach with a tower is a very different job from one in the middle of a roof on a terrace with no rear access.