Slate roofing has been part of the Irish landscape since at least the 13th century, becoming widespread from the 18th century onwards. Much of the slate used on Irish roofs came from across the Irish Sea, from the great Welsh slate quarries such as Penrhyn and Dinorwig, which were the two largest slate quarries in the world.
With cities like Dublin and Belfast growing fast, and sea transport being far more reliable than road, Welsh slate was the more practical option.
Despite overshadowing by our Welsh neighbours, Slate quarries were dispersed across Ireland, most notably in places like Valentia Island in Kerry, Killaloe in Clare, Ahenny in Tipperary, Bangor in Down, and Ballinascarthy in Cork. These were local industries but at times also supported larger markets and exploited rivers and coastlines to allow for business to grow.
Many smaller quarries were also in operation throughout the country but didn’t gain mass levels of production due to location. To date, the Geological Survey of Ireland has recorded over 200 references to slate quarries across the island. While Welsh slate may have dominated commercially, Irish slate quietly roofed homes, paved floors, and even marked graves in a way that reflected the life and needs of the communities around it.
Slate from the Land
Irish slate quarries often had strong links to rivers. Places like Killaloe and Portroe made use of the nearby River Shannon to transport slates. Valentia slate, on the other hand roofed some houses in the locality but was mostly used for flagstones, gravestones, railway sleepers, and even for drying floors in sugar and coffee houses overseas.
Ahenny in County Tipperary was once a hive of the Irish slate industry. In the 1860s, the Victoria Slate Mining Company (VSMC) built a village there for workers, based on the Welsh quarrymen’s cottages. At its peak, around 90 men worked in and around the quarry which employed quarrymen, slate-makers, blacksmiths, carpenters, and carters. Before the VSMC was established, Landowners in the area often dug what they could from their own ground and then carted their crudely made slates into towns to sell such as Fermoy, Dungarvan, or Clonmel. It was a slow, local trade that rapidly changed when the quarry infrastructure was put in place.
Tools of the Trade
The tools of the slater haven’t changed much in centuries. Working with slate isn’t something that lends itself easily to electricity. Machines tend to leave clean, straight edges but slate roofs need a soft bevel to keep out wind and rain. That bevel still comes best from hand tools, guided by skill and experience.
In 1971, the National Museum of Ireland commissioned Ahenny based blacksmith James Walsh to craft the traditional slater’s tools pictured below, helping to preserve a little of that knowledge before it disappeared from daily use.
Figure 1 F:1971.118 © National Museum of Ireland
The larger chisel pictured above is called a scalloper, it was used to mark a guideline for the diamond saw. The chisel below was used for splitting slate cleanly along its grain.
Figure 2 F:1971.119 © National Museum of Ireland
The Slater’s Sax (also referred to as slater’s knife or hewing knife) could be found in use both at the quarry and on the rooftop it is a sturdy, sharp-edged tool used to trim slates and punch holes. It was to a slater what the hammer was to a blacksmith.
Figure 3 F:1971.120 © National Museum of Ireland
The slater’s hammer or combination tool is perhaps the most universal tool — part knife, part hammer, part punch. It could do nearly everything and remains almost unchanged today. The below tool was found in the basement of Cabragh House, Dublin (built in the 16th century) where it was likely used to slate the roof that once belonged to the infamous “hanging judge” Lord Norbury. 
Figure 4 F:1947.170 © National Museum of Ireland
One of the most essential tools is the slater’s ripper, used to remove slates. It’s a long, flat tool that’s slid underneath a slate to hook the nail beneath. The ripper is then pulled or struck with a hammer to pop the nail free. It’s clever, efficient, and still in use today.
Figure 5 F:1976.318 © National Museum of Ireland
Life on the Rooftops
Working slate, whether in the quarry or on the roof, was not for the faint-hearted. Accidents were common and working conditions were tough. This led to the formation of slater’s unions and movements that pushed for better pay and safer conditions. Slaters played a vital role in the wider history of Irish labour and trade, something that’s been explored more deeply by my colleague Noel Campbell in his piece on Trade Union Banners of the Regular Operative Slaters of Dublin. Below is a badge worn by members of the Amalgamated Slaters, Tiler’s and Roofing Operatives during public demonstrations towards the end of the 19th century.
Figure 6 F:1972.113 © National Museum of Ireland
Much like any trade today it took five years to become a qualified slater, although at the turn of the last the terms and conditions were very different as can been seen in the below indenture from 1899 in which William Kerr was given his father’s consent to train as a slater under the Amalgamated Slaters and Tilers of the city of Dublin. It is likely that William spent most of his apprenticeship on roofs and less time in quarries as the majority of Dublin was roofed with Welsh slates.
Figure 7 F:1972.180 © National Museum of Ireland
As the 20th century wore on, Irish slate quarrying began to decline. Cheaper materials came in, competition from larger Welsh quarries grew, and many Irish sites were simply too remote or lacked the infrastructure to keep up. Valentia is currently the only quarry discussed above that is still in operation on a small scale. With the remainder of the quarries, the tools and skills were still there but modernity moved on. Even so, quarrymen and slaters remain an important part of Ireland’s craft and trade history. Slate roofing kept the rain out and in doing so connected the people to their own architecture and landscape.
Published 19 December 2025
Further reading:
Jenkins, J. C., The Slate Roof Bible (2003)
Valentia Slate: A heritage stone Project MUSE - Valentia Slate, County Kerry: A heritage stone