Chimney Capping: Closing Off a Flue You Don't Use
Capping an unused chimney costs €300 to €900 in Ireland. A cap keeps rain and birds out of a flue that no longer has a fire under it, and it must let air through. A flue sealed tight at the top and blocked at the fireplace has no airflow, so moisture condenses inside it and comes through the chimney breast as damp.
How a flue is capped, why it needs a vent, and the other end of the job.
Free, no obligation. One local company prices it, not five.
- €300 to €900capped with a vent
- Top and bottomboth need air
- €600 to €1,500to take the stack down instead
Three ways to cap a flue
| Method | What it is | Suits |
|---|---|---|
| A capping cowl | A vented cap that clamps or beds onto the existing pot | A flue you may use again |
| A clay or metal hood | A fixed vented cover bedded in mortar on the pot | A flue closed for good, pots kept for the look |
| Pot off, slab on | The pot removed and a vented slab or slate bedded over the flue | A flue closed for good on a stack that stays |
The other end
The fireplace needs a vent too. If the opening is bricked up or boarded, a small grille goes in it so air can rise through the flue and out at the cap. Top and bottom both open a little: that is what keeps a dead flue dry.
Cap it or take it down
A sound stack that only lets in rain is worth capping. A stack that also needs repointing, flashing and flaunching may cost more to keep than to remove: taking it down below the roof is €600 to €1,500. See chimney removal before you decide.
Capping, priced
| Job | Typical cost | What moves the price |
|---|---|---|
| An unused chimney capped, with a vent | €300 to €900 | A cap on the pot, or the pot off and a slab on |
| A cowl supplied and fitted | €100 to €450 | The type of cowl and how it's reached |
| Flaunching renewed, pots re-bedded | €200 to €1,200 | How many pots, and whether any are cracked |
| A stack taken down below the roof | €600 to €1,500 | Making good the roof over it |
Repair work on a house is at the reduced 13.5% VAT rate. Ask for a written price that includes it, and says whether scaffolding is in it.
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More on chimney repairs
Costs, leaks, mortar, flues and rebuilds.
What chimney repairs costEvery job, priced. Repointing is €300 to €1,500.
A leaking chimneyWhere the damp shows tells you where the water gets in.
Repointing a stackWhen new mortar is enough, and when it isn't.
Lining a flueFor stoves, tar and cracked flues. €800 to €2,500 fitted.
Rebuilding a stackA lean, bulging or loose bricks. €800 to €2,000 above the roofline.Chimney repair in every county
- Carlow3,372 homes built before 1946
- Cavan4,152 homes built before 1946
- Clare6,309 homes built before 1946
- Cork37,465 homes built before 1946
- Donegal6,974 homes built before 1946
- Dublin79,150 homes built before 1946
- Galway10,117 homes built before 1946
- Kerry7,666 homes built before 1946
- Kildare5,606 homes built before 1946
- Kilkenny6,287 homes built before 1946
- Laois4,323 homes built before 1946
- Leitrim2,466 homes built before 1946
- Limerick11,830 homes built before 1946
- Longford2,224 homes built before 1946
- Louth6,764 homes built before 1946
- Mayo7,592 homes built before 1946
- Meath6,839 homes built before 1946
- Monaghan3,868 homes built before 1946
- Offaly4,608 homes built before 1946
- Roscommon4,227 homes built before 1946
- Sligo4,130 homes built before 1946
- Tipperary12,246 homes built before 1946
- Waterford7,755 homes built before 1946
- Westmeath4,684 homes built before 1946
- Wexford8,936 homes built before 1946
- Wicklow8,488 homes built before 1946
Check your chimney
Four taps: what's wrong, the height of the house, what the stack is built of and what it's used for. You see the likely job and our price for it. Your number is only asked for at the end, if you want one chimney repair company that covers your county to ring you.
Questions people ask
Can I cap a chimney that has a gas fire?
No. A flue in use by any appliance needs the right terminal, not a cap. Ask a registered gas installer.
Will capping stop the damp on my chimney breast?
If rain down the flue is the cause, yes. If the flashing or the joints are letting water in, no.
Does a cap need scaffolding?
On a bungalow, usually not. On two storeys, usually.
Can a capped chimney be reopened?
Yes, if it was capped with a cowl or hood. The flue is checked by camera and swept first.
Is a chimney balloon the same thing?
No. A balloon blocks the draught at the fireplace. It does nothing about rain at the top.
Get a price for your chimney repair
One chimney repair company that covers your county. Free, no obligation. Nothing is booked until you say yes.