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The Roofing Slate of Ireland
by Joe Jenkins
Who knows anything about Irish roofing slate? Even when I was attending the International Federation of Roofing Trades Congress in Dublin, Ireland a few years ago, no one there knew anything about Irish roofing slate, nor could anyone produce one for me to look at. It wasn’t until Mary Lou Willits of the Slate Valley Museum in Granville, New York showed up on the scene that this mystery became solved. Mary Lou and her architect husband, David Wright, independently researched the slate quarry region of southern Ireland, located the old quarry sites, sought out the old-timers who knew about the industry (which is now virtually defunct), then led a tour through the countryside, villages, quarries, and pubs they had discovered and mapped out. The tour was in September of 2006. I tagged along, and this is what I found.
At one time, hundreds of slate quarries operated in Ireland, but the Irish potato famine in 1847 undermined the Irish slate industry when many Irish emigrated to the U.S. Today there is only one working slate quarry in Ireland — the Valentia quarry on Valentia Island off the southwest coast. Valentia, now a small operation (two men were working there when we dropped in) no longer produces roofing slate.
There were several other working slate quarry areas in southern Ireland at one time, including Ormonde, Victoria and Killaloe — three now defunct quarry sites that we visited during the tour (see map below).
The Ormonde and Victoria quarries are located in the same valley in southeastern Ireland, northwest of Waterford near Tullaghhought. The Ormonde quarries (below) are in County Kilkenny and were worked until approximately 1935. This “slate valley,” extends 2 1/2 miles to include the Victoria quarry in County Tipperary (also below). Both produced a black slate of high durability — a slate which can still be seen on many of the local houses and buildings.
Our tour took us through rich farmland, past herds of beef cattle, potato fields, hills covered in purple heather, yellow gorse, wild foxgloves, and red fuschia growing wild in the hedges. Blackberry thickets laden with plump fruit were everywhere. The heavy rains during our visit swelled the rivers. Abandoned ruins of castles dotted the landscape — some were still inhabited. The mild climate in this part of the world rarely causes frost. Even palm trees were growing in the southern extremes of Ireland. Large Celtic crosses dating back to the 700s remain upright in rural graveyards. Our bus traveled many a narrow, winding road lined with tall hedges. Stone walls criss-crossed the open countryside.
The Killaloe Quarry, north of Limerick, just east of Lough Derg near Lackamore, dates back to 1014 and was the largest slate quarry in Ireland in the 1920s to the 40s. Some of the slate was exported to Scotland, some to Holland, but most was used in Ireland. According to an oral history given to us by Fin O’Driscoll, a blind octogenarian, the Killaloe quarries were once operated by his father, who began the operation in 1923. He had learned about slate from his father. In the 1930s, the slate operation had approximately 180 workers and worked the slate to a depth of 230 feet. A major landslide caused by a storm closed the quarry in 1956. Today, 17 million tons of slate debris lie in small mountains scattered through the old slate area, now overgrown with shrubs and trees. The quarries today are only deep, turquoise, cliff-lined lakes.
The Valentia Quarry (see below), on Valentia Island off the southwest corner of Ireland south of the Dingle Bay, was first opened in 1816 by the Knight of Kerry. Most of the slate was processed in Knight’s Town on the northeast corner of the island. The quarry’s name is derived from an anglicized Gaelic term meaning "flat land at the mouth of the river." It began as an open hole and eventually developed into a mine that extended about 200 meters into the mountainside. The slate is dark gray with a purplish hue, looking black on a roof and referred to as “blue-gray” by the manufacturers. It is very durable and long-lasting, but with a course grain that makes economical roof slate production difficult. Roofing slate only ever comprised about 20% of the production of the quarry, with the remainder being made into structural slate, hearths, mantels, garden furniture, gravestones, celtic crosses, etc.
Up to 500 people were employed in the quarry operation in the 1840s. By the 1860s, 2,000 tons of slate were being produced, but production declined in the 1870s when Welsh and American slates flooded the market. The quarry continued to decline, then closed in 1884, but reopened in 1900 only to be closed again by a cave-in at the mouth of the quarry in 1911. The rock-fall seemed to ring the death knell for the quarry, leaving it to lie dormant for many years. Eventually, interest again developed in reopening the Valentia site. In 1999, production renewed at the quarry, now a gaping triangular hole in the mountainside. Today, Valentia slate production is modest, with approximately 10 people employed at the site. Although no roof slate is produced, vast reserves of slate rock remain, with great potential for expansion should the investment capital and business interest develop.
There are many buildings in southern Ireland and elsewhere throughout Ireland and parts of Europe that remain roofed with original Irish slate. Although some of these old roofs need repair and restoration, the durable slate itself is showing no signs of giving up or even slowing down. At least one roof slate salvage operation is in business in southern Ireland in the form of Killoran Slate Quarry, Ltd, in Nenagh, County Tipperary (IrishSlate.com), which is also a broker for new roofing slate, but not a quarrier. Killoran salvages original Irish slates, retrims them, then sells them for restoration purposes.
Although this is obviously not meant to be a comprehensive report on Irish slate, it nevertheless shines a light on a long neglected topic. If you go looking for the quarries, pack an umbrella, but don’t worry about getting thirsty — a cozy pub will only be a stone’s throw away.