Chimney repair
across Laois
Turf-tarred flues in the bogland west, anthracite and culm in the south, airtight new build around Portlaoise. Free CCTV survey, insurance claims handled start to finish, certificate the day we finish.
Three fuel traditions in one county, and the census shows it
Search for a chimney man in Laois and you will be offered the midlands. One competitor covers Athlone, Tullamore, Mullingar and Portlaoise from a single page. Another has a page called, literally, "The Midlands". Both are roofing companies. Not one of them has a page about Laois.
That is worth saying because Laois is not an undifferentiated place. It burns three different fuels in three different parts of the county, and each one leaves a flue in a different state.
Census 2022 puts 42.9% of Laois households on oil for central heating, close to the national 39%, and it recorded housing stock up 5%, from 32,794 dwellings to 34,443, matching the national growth rate exactly. On those two numbers Laois reads as ordinary commuter Leinster, and around Portlaoise and Portarlington that is what it is.
Then there is the other number. 11.5% of Laois households heat mainly with peat, including turf, three times the national figure of 3.7%. That is the bogland west and north of the county, and it is not a rounding error.
And in the south there is something no other county on this site has: the Leinster Coalfield. The Castlecomer Plateau runs up out of Kilkenny into Laois at Wolfhill and Doonane, its seams are anthracitic, and they were worked from the mid seventeenth century until 1969. That district burns coal, and it has a local word for the crushed coal-and-shale that came with it: culm.
Straight about distance: the van works out of Clonegall, Co. Carlow, so Portlaoise is around an hour and the south of the county is considerably closer. For a rebuild, a reline or an insurance job across several days that is workable. For a small call-out it is not, and you will be told so on the phone.
New houses, airtight, and a stove that will not draw
Laois added roughly 1,650 dwellings between the 2016 and 2022 censuses, and the growth concentrated on the Dublin side of the county. Portlaoise is the county town and a commuter town. Portarlington sits on the River Barrow and straddles the boundary with Offaly, so half the town's post is addressed to a different county from the other half.
Almost every one of those new houses is airtight in a way the older stock is not, and that is the single most common reason a nearly-new Laois house has a stove that smokes.
A chimney does not suck. It is pushed. Hot gas in the flue is lighter than the cold air outside, so it rises, and the air it displaces has to come back into the room from somewhere. In a draughty farmhouse it comes through the fabric of the building without anybody noticing. In an airtight house there is nowhere for it to come from, so the flue stalls and the smoke comes into the room instead.
TGD J 4.2.1 is specific about the fix. Any non-room-sealed solid fuel appliance needs a permanent vent of at least 6,500 mm² of free area, plus a further 550 mm² per kilowatt above 5 kW. An 8 kW stove therefore needs 8,150 mm². There is no under-5kW exemption in Ireland. That is UK Approved Document J, and it gets quoted at Irish homeowners constantly by people who have not checked.
The version of this that catches people out is a house that worked fine and then stopped. New windows go in, the fabric tightens, and the stove starts smoking three weeks later. Nobody connects the two events, because they do not look related.
What turf actually does to a flue
11.5% of Laois households heating mainly with peat is three times the national 3.7%, and the pattern is geographic rather than random: the bog country running west and north from Mountmellick and Clonaslee toward the Offaly boundary. Nationally turf burning is falling steadily, from around 90,000 households in 2011 to 79,000 in 2016 and roughly 68,000 in 2022, but it has not fallen evenly, and Laois is one of the counties where it held on.
Turf is not bad for a chimney. It is simply harder work for one, for two reasons that compound.
It carries moisture. Even well saved turf holds considerably more water than kiln-dried timber, and every bit of that water has to be boiled off using heat that would otherwise have gone up the flue as temperature. A cooler flue is a flue in which combustion gases reach their condensation point lower down.
It burns at a lower flame temperature. Turf gives a long steady output rather than a hot fast one, which is exactly why people like it. The consequence upstairs is that the gases cool sooner on the way up and lay down tar higher in the flue than timber would.
Tar is the thing that matters. It is the fuel for a chimney fire, and a chimney fire cracks liners and flue tiles even when the house comes through untouched. So the honest advice for a turf-burning house is not to stop burning turf. It is a shorter sweeping interval than a timber-burning neighbour needs, and a camera down the flue often enough to know what is up there.
One more thing specific to this fuel. A turf fire is often left in overnight, banked down and smouldering. Smouldering is the tar-producing condition: low temperature, low airflow, incomplete combustion. The habit that keeps the kitchen warm until morning is the same habit that loads the flue.
Anthracite, culm, and why they fail differently
This part is genuinely local. The Leinster Coalfield sits on the Castlecomer Plateau across Carlow, Kilkenny and Laois, and its Laois end was worked at Wolfhill and Doonane. There are at least eight seams and all of them are anthracitic. Mining ran from the mid seventeenth century until 1969.
Because the coal measures were tilted, a great deal of the deposit was crushed and mixed through the boundary shale, producing a lower-grade material the district still calls culm. Anthracite and culm are two different fuels with two different consequences, and neither behaves like turf.
Anthracite is low in volatiles. That means it lays down markedly less tar than turf or unseasoned timber, so the tar problem largely goes away. What replaces it is sulphates. Coal combustion gases carry sulphur compounds, and in an unlined flue those soak into the mortar joints year after year and react with the cement.
Culm burns slow and cool. It was traditionally burned as a long, low fire, which brings the condensation problem straight back. The flue runs cool and the gases condense inside the masonry instead of leaving the top of it.
So a chimney at Wolfhill and a chimney outside Clonaslee will have been failing by two different mechanisms for fifty years, and they need different things looked at. The sweeping interval is the wrong question in the south of the county; the state of the mortar joints is the right one. That distinction is not something a regional roofing page is going to make.
The Slieve Blooms, and weather that finds every crack
Laois is landlocked, so there is no salt argument to make here and it would be dishonest to import one from a coastal county. What Laois has instead is high ground. The Slieve Bloom Mountains run along the Offaly border above Clonaslee, Rosenallis and Camross, and houses on that side of the county sit in conditions the Barrow valley does not experience.
The mechanism is driving rain and freeze-thaw rather than salt. Rain driven horizontally against one face of a stack for days at a time saturates the masonry, and saturated masonry that then freezes expands from inside the pore structure. It is a slow process and it is entirely one-sided: the exposed face fails while the sheltered face of the same stack stays sound.
The practical tell is asymmetry. If one face of the stack is soft enough to take a screwdriver and the opposite face is not, that is not a defect in the original work. That is exposure, and it means the repointing specification matters more here than it does ten miles east.
The related mistake is repointing an exposed upland stack in too hard a cement mix. A rigid face traps moisture behind it, and the next freeze pushes the stone apart instead of the joint. The joint is meant to be the sacrificial part.
2,576 vacant dwellings, and 776 of them empty since 2016
Census 2022 recorded 2,576 vacant dwellings in Laois, about 7.5% of the county's stock, down 14% from 3,007 in 2016. Buried in that is a more useful figure: 776 dwellings were recorded vacant in both the 2016 and the 2022 census. Those are houses that stood empty across two counts, and a fair number of them are now being bought and renovated.
A flue that has not been lit in six years is a different proposition from one in daily use, and three things follow from that.
Jackdaws. An unused pot is an attractive nest site, and a jackdaw nest is the single most common cause of a smoke-back on a first fire in a renovated house. They are also surprisingly substantial: a nest can fill a metre or more of flue.
No record. There is no sweeping history, no documentation of the flue's condition and nothing an insurer can be shown if something goes wrong later. Establishing that at the start costs an hour.
Frost damage nobody watched. A stack that has been unheated for six winters has had no warm flue drying it from the inside. Damage accumulates faster on a cold chimney than on a working one, and it accumulates unobserved, because nobody was in the house to see the damp patch appear.
If you have bought one of these, the sequence is: camera down the flue, then light the fire. Not the other way round.
Why Laois chimneys fail
Sulphate attack, and why stacks lean
Burning coal and turf produces sulphates. In an unlined flue those gases soak into the mortar joints and over years react with the cement and expand it. The joints swell, the stack grows unevenly and it starts to lean, almost always away from the prevailing wind because that face stays wet longest. It does not stop and it cannot be pointed out of existence. In a county with this much turf and a coal-burning south, it is the most common structural finding on older stock.
Tar accumulation from turf and smouldering fires
Covered above, and specific to the west of the county. The finding on camera is a glossy black deposit rather than the loose soot people expect, and once it has hardened it does not come off with a brush alone. Tar is what burns in a chimney fire, and a chimney fire cracks flue tiles and parge coats even where the house itself is untouched.
Flaunching, the most common single failure
Flaunching is the sloped mortar cap that beds the pots and sheds water off the top of the stack. It is the most exposed mortar on the building and it goes first everywhere, but on a Slieve Bloom foothill stack taking driving rain it goes faster. When it cracks, rain runs down inside the masonry instead of off the top, and the first sign indoors is a damp patch high on a chimney breast after heavy rain.
Lead flashing at the roofline
Where the stack passes through the slates there should be lead soakers and a stepped flashing dressed into the mortar joints. Plenty of older Laois houses have a mortar fillet instead, and a mortar fillet cracks within a few winters. Water then tracks into the roof timbers, which is how a chimney problem quietly becomes a roof problem.
Oversize flues serving small stoves
A great many older Laois farmhouses had a stove dropped into a fireplace built for an open turf fire. Those flues are enormous by modern standards, because an open turf fire needed the volume. The stove cannot fill it, so the gases slow, cool and condense on the way up instead of drawing cleanly. That condensate is acidic and it goes into the masonry. An oversize flue is a genuine safety problem, not merely an inefficiency.
Ventilation in newer housing
Laois stock grew 5% between 2016 and 2022, in line with the national rate, and that growth is concentrated around Portlaoise and Portarlington. New houses are airtight. TGD J 4.2.1 requires 6,500 mm² of permanent free vent area plus 550 mm² per kilowatt above 5 kW, so an 8 kW stove needs 8,150 mm². This is the most common single fault on a modern house and the cheapest to correct.
What chimney damage looks like from inside the house
Almost nobody rings about a chimney. They ring about something else that turns out to be the chimney.
- →A damp patch high on the chimney breast. Usually flaunching or flashing. It appears after heavy rain and fades between, which is why people live with it for a year.
- →The fire is harder to light than it used to be. On a turf-burning house that often means tar narrowing the flue. It comes on gradually enough that people adapt to it rather than noticing it.
- →Mortar soft on one face of the stack only. Classic upland exposure. The weather face fails years before the sheltered one.
- →Debris in the grate. Mortar and brick fragments coming down mean the inside of the flue is breaking up.
- →The stack looks off plumb. Sight it against the gable on a clear day. If it is leaning, stop using the fire.
- →Twigs in the grate in spring. That is a jackdaw nest above, and it is the classic finding in a house that has been standing empty.
- →A roaring sound with no obvious cause. That is a chimney fire in progress. Ring 999, then have the flue inspected before it is used again.
Worth a plain word on smoke alarms while we are here. Census 2022 recorded 1,292 Laois homes with no smoke alarm at all. If yours is one of them and you burn solid fuel, that is the cheapest thing on this page to put right, and it is not a job that needs us.
If you are unsure what you are looking at, the photo-based damage assessment gives a straight answer before anybody visits.
Every type of chimney repair, done properly
Relining. A stainless liner sized for the appliance, fed from the top, connected at the stove and sealed at the pot. Under TGD J Table 2 a closed appliance up to 20 kW burning timber, peat or bituminous coal needs at least 150 mm internal diameter; only smokeless fuel or wood pellets may drop to 125 mm. Worth knowing in a turf county, because turf sits on the 150 mm side of that line.
Tar removal. Hardened tar does not come off with a brush. It needs rotary work and sometimes chemical treatment first, and on a badly loaded flue relining is the cheaper answer than repeated attempts to clean it.
Partial rebuild. The stack taken down to sound masonry above roof level and rebuilt. On a sulphate-damaged stack this is usually the right call, because the damage concentrates in the exposed head.
Full rebuild. Down to the roofline and back up, with new flaunching, new pots and new lead.
Repointing in the correct mortar. Which matters more on an exposed Slieve Bloom foothill stack than in the Barrow valley, because too hard a mix traps moisture behind a rigid face and the next frost does the damage.
Flaunching renewal. The mortar cap cut out and recast to the correct fall, pots rebedded. Cheap, quick, and it prevents the expensive job.
Lead flashing. Proper code lead, stepped and dressed into the joints with soakers under the slates. Not a mortar fillet.
Ventilation corrections. Cutting in a permanent vent to the 6,500 mm² minimum, or more where the output demands it.
Fire and storm damage. Assessed, documented and rebuilt, with the insurance handled in parallel. See insurance and fire damage.
More detail on the main chimney repairs page and the lining and cleaning page.
What chimney repair costs in Laois
Real ranges, including VAT, labour, materials, scaffold or hoist where needed, waste away and the certificate.
| Work | Typical range |
|---|---|
| CCTV survey | Free with any repair |
| Flaunching renewal | €450 – €1,100 |
| Lead flashing | €600 – €1,400 |
| Relining | €1,400 – €2,800 |
| Partial rebuild, above roof level | €2,000 – €4,500 |
| Full rebuild, single stack | €3,500 – €8,000 |
| Full rebuild, double stack | €8,000 – €14,000 |
| Insurance excess on an approved claim | €200 – €300 |
A detached house outside Abbeyleix or Mountrath with a yard to set up in sits at the bottom of its band. A tall stack on a Portlaoise town-centre terrace with no rear access, needing scaffold and a licence from Laois County Council to stand it on a public footpath, sits at the top. Nobody can tell you which you have over the phone, which is why the survey is free and the quote follows in writing.
Indicative only. An exact figure follows the survey, in writing, before any work starts.
We handle the Laois claim from start to finish
Storm damage and chimney fires are covered by most Irish household policies. Gradual deterioration is not. That single distinction decides most claims, and it gets decided by how the damage is documented rather than by what happened on the roof.
In a turf-burning county the distinction matters more than average, because a chimney fire is a covered event and the tar that fed it accumulated gradually. Documenting the fire damage properly, while it is still fresh and before anything is touched, is what keeps the claim on the right side of that line.
In practice that means CCTV footage of the flue, photographs of the stack before anything is disturbed, a written report describing the mechanism of failure, and an itemised costing set out the way loss adjusters expect. Then Johnny deals with the adjuster directly.
On an approved claim you pay your excess, typically €200 – €300, and nothing else.
One thing worth saying plainly, because it gets repeated as fact and it is not: no Irish insurer makes annual sweeping a condition of cover. Sweeping is worth doing and a record of it helps a claim, but nobody voids a policy over a missed year.
Full detail on insurance and fire damage work, and on how a claim actually runs.
What needs doing now, and what can wait until spring
| Finding | How urgent |
|---|---|
| After a chimney fire | Do not relight until inspected |
| Leaning stack | Stop using the fire. Same week. |
| Heavy tar visible on camera | Before the next heating season |
| First fire in a house that stood empty | Survey before lighting, not after |
| Loose pots over a public footpath | Urgent. It is a street below. |
| Mortar soft to a screwdriver on the weather face | Before winter |
| Cracked flaunching, no damp yet | This year, not this week |
| Pointing tired but sound | Monitor. Often several years left |
The fourth row is the one that gets skipped most often, because a house that has just been bought has a hundred other things wanting money and the fireplace looks fine from the room.
Every corner of the county
Laois has one verified Eircode routing key of its own, and a border town that has never respected the county line.
| Key | Post town |
|---|---|
| R32 | Portlaoise |
| R35 / R45 | Tullamore and Edenderry (Co. Offaly keys, but the boundary is close enough that they come up on the Laois side) |
Portarlington sits on the county boundary with Offaly. The town straddles the River Barrow with part of it in each county, so two neighbours on the same street can have addresses in different counties. If that is you, the Offaly page is worth a look as well. The work is the same and so is the van.
Mention the town, the fuel you burn and whether there is rear access when you ring, and the estimate lands closer first time. The fuel matters more than people expect, because it tells us what will be on the camera before we arrive.
One tradesman, not a call centre
Johnny Roberts runs J.Roberts Solid Fuel Services on his own out of Clonegall, Co. Carlow. Ring the number and you get him. The person who surveys your chimney is the person who does the work.
Every top result for chimney work in this county is a roofing company. A roofer sees the top of a roof; here the flue is the whole trade. That is the difference, and it is checkable rather than a boast.
There is no statutory register for solid fuel work in Ireland, so what is actually checkable is the insurance, the work itself and the certificate. All three are available to see.
Chimney repair in Laois. FAQ
Do you actually travel to Laois?
Yes, for work that justifies it. The van works out of Clonegall in Co. Carlow, so Portlaoise is around an hour and the south of the county considerably less. For a rebuild, a reline or an insurance job running across several days that is straightforward. For a small one-off call-out it is not sensible and you will be told so on the phone rather than after a wasted morning. Laois jobs get grouped onto one run where the dates allow it.
Does burning turf damage a chimney?
It does not damage a sound flue, but it loads one faster than timber does. Census 2022 recorded 11.5% of Laois households heating mainly with peat including turf, against 3.7% nationally, so this matters here more than in most counties. Turf carries moisture and burns at a lower flame temperature than well seasoned hardwood, so the gases cool sooner on the way up and deposit tar higher in the flue. The consequence is a shorter sweeping interval and a genuine chimney fire risk if that is ignored, not a reason to stop burning turf.
We burn anthracite from around Wolfhill. Is that different?
Yes, and south Laois is one of the few places in Ireland where the question comes up at all. The Leinster Coalfield runs up into the county at Wolfhill and Doonane and its seams are anthracitic, worked from the mid seventeenth century until 1969. Anthracite is low in volatiles, so it lays down far less tar than turf or unseasoned timber. What it does instead is produce sulphates, and sulphates are what attack mortar joints from inside an unlined flue over years. Culm, the crushed coal blended with shale that the district is known for, burns slow and cool, which brings the condensation problem back. The fuel changes what fails, so it changes what the survey is looking for.
How much does a chimney rebuild cost in Laois?
A partial rebuild above roof level typically runs €2,000 to €4,500. A single stack from the roofline is €3,500 to €8,000. A double stack is €8,000 to €14,000. Relining is €1,400 to €2,800. The survey is free and nothing is quoted until a camera has been down the flue. A detached house outside Abbeyleix with a yard to work from sits at the bottom of its band; a tall stack on a Portlaoise town-centre terrace with no rear access sits at the top, because of scaffold.
My chimney is leaning. Is that urgent?
Treat it as urgent. It is usually sulphate attack, where flue gases have soaked into the mortar over years and expanded it, and it almost always leans away from the prevailing wind because that face stays wet longest. It does not correct itself and it does not stop. Stop using the fire and ring somebody the same week. On older Laois houses that have burned turf or coal in an unlined flue for decades this is the most common structural finding.
Why does my chimney smoke in a house that is only a few years old?
Almost always air supply rather than the flue. Laois housing stock grew 5% between 2016 and 2022, from 32,794 dwellings to 34,443, matching the national rate, and most of that is around Portlaoise and Portarlington. New houses are built airtight. TGD J 4.2.1 requires a permanent vent of at least 6,500 mm² of free area for any non-room-sealed solid fuel appliance, plus 550 mm² per kilowatt above 5 kW, so an 8 kW stove needs 8,150 mm². There is no under-5kW exemption in Ireland; that is UK Approved Document J and it gets quoted here by mistake.
The house was empty for years before we bought it. What should we check?
The flue, before you light anything. Census 2022 recorded 2,576 vacant dwellings in Laois, and 776 of those were recorded vacant in the 2016 census as well, so a house that stood empty across both counts is not unusual here. A dormant flue collects jackdaw nests, and a nest is the single most common cause of a first-fire smoke-back. Beyond that there is no sweeping record, no documentation of the flue's condition and nothing an insurer can look at. An hour with a camera before the first fire is the cheapest part of the whole purchase.
What does the free survey involve?
About an hour. A look at the stack from the roof, a CCTV camera down the flue, a check of the flaunching, the pots and the lead flashing where the stack meets the slates, and a look at the fireplace and any damp staining inside. You get told what is wrong, what needs doing now and what can safely wait until spring. No charge, and the footage is yours to keep whether or not you use us.
Why is there a damp patch on the chimney breast upstairs?
Usually one of three things. Failed flaunching, the mortar cap on top of the stack, which cracks and lets water straight down through the masonry. Failed lead flashing where the stack passes through the roof. Or an unlined flue, where condensing flue gases carry moisture into the masonry, which is the one turf and culm make more likely. A survey separates them quickly and they need completely different fixes, so guessing is expensive.
Does my flue have to be lined?
Not automatically. TGD J requires the flue to be suitable for the appliance, not lined as a matter of routine. Lining becomes necessary where the flue is oversize for the stove, leaks between floors, or shows cracking on camera. Older Laois farmhouses often have a wide flue built for an open turf fire, and a small stove connected to it means the gases cool and condense inside the masonry instead of leaving. An oversize flue is a safety problem, not just an inefficiency.
Is there a registration scheme for chimney work in Ireland?
No. There is no statutory register for solid fuel chimney work in the Republic. HETAS withdrew from Ireland in March 2022 and is a UK body in any case, and DEFRA exemption and Smoke Control Areas are UK law that does not apply here. Gas has RGI; solid fuel has nothing equivalent. What you can actually check is public liability insurance, previous work in your own area, and the certificate issued at the end. Ask any contractor for all three.
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Chimney trouble in Laois?
The survey is free and a camera goes down the flue before anybody quotes. Tell us what you burn when you ring. Turf, coal and timber each change what we expect to find.