Why chimneys leak
Almost every Dublin house built before the 1990s has at least one chimney. A chimney pushes through the roof and asks brick, mortar, lead and tile to stay watertight together, in wind that drives rain sideways. Something usually gives. The pointing between the bricks washes out and the whole stack soaks up water like a sponge. The flaunching around the pots cracks. The flashing that seals the stack to the roof was often done on the cheap, mastic instead of stepped lead let into the brick, and it lifts. Inside the house it shows as a damp chimney breast or a stain on the ceiling beside it.
What we repair
- Repointing: raking out the old mortar and repointing the stack in a mix that suits the brick.
- Flaunching and pots: rebuilding the mortar cap, resetting or replacing pots, fitting cowls.
- Flashing: stepped and apron flashings, soakers and back gutters renewed in lead, dressed and pointed into the brick, not smeared with sealant.
- Capping: disused chimneys capped with a vented cap so the flue stays dry but still breathes.
- Valleys: lead valleys stripped and re-laid, or a GRP valley trough fitted on tiled roofs.
- Ridges: ridge tiles re-bedded in mortar, or replaced with a dry-ridge system that needs no mortar at all.
What affects the price
Every chimney job is priced after a free roof check. What moves it:
- Height and access: a stack on a two-storey ridge usually needs a chimney scaffold or tower, priced separately; flashings and valleys lower down are often done from a roof ladder.
- Extent of the damage: a few open joints are repointed in a morning; a stack that has soaked up water for years may need the flaunching rebuilt and the top courses relaid.
- Size: two stacks, or a long valley, take longer than one.
The price is agreed before any work starts, and there are no hidden charges.
The free check comes first
We go up and look, because you cannot diagnose a chimney from the garden. The stack, flashings, back gutter, valleys and ridge are photographed, we check the attic for the wet line, and you get photos of what we find and your quote with no hidden charges. If the stack is beyond repointing, we tell you and quote the alternative.
Guarantee
Chimney and leadwork repairs are guaranteed and we are fully insured. Oisin Roofing & Guttering has completed over 1,700 roofs across Dublin, Wicklow and Kildare, and a chimney that still leaks after someone else has been at it is a call we know well.