The Mill Houses of Blarney 

James St. John Jefferyes inherited the Blarney estate in 1740 and eventually set about developing industry in the village, building an inn, a new church, 90 houses and some flax mills – a development noted with approval by the English agronomist Arthur Young in his ‘Tour of Ireland.’

In Issue No. 1, ‘Old Blarney’ Journal, author Colman O’Mahony states in his article, ‘Blarney Woollen Mills and the Mahony Family’ that “Timothy Mahony was born at Dromore Castle, Co. Kerry in 1711 and in the early 1740’s he left his home and came to Cork. By 1750 he had established a small woollen mill near the city – traditionally at, or near, Glanmire. A few years later the business was moved to Rochestown. Mahony’s business was firmly established at Blackpool by the end of the eighteenth century. By the late 1790’s the firm was advertising under the more familiar names of Martin and Tim Mahony.” He goes on to say that, “In 1824 Martin transferred the woollen business from Blackpool to a former flax mill at Blarney. The Mahonys extended the Blarney factory in the mid-1840s by building a new, 85 feet by 40 feet, wing. By the early 1860s it had been necessary to extend the mills further. Some 200 workers were then employed in the mill and the weekly wage bill averaged about £120.” 

“The firm was now named ‘Martin Mahony & Bros., Ltd.’ but was destroyed by fire in 1869. The mill was re-built and in full operation again by 1871 with the most technically advanced machinery and labour-saving devices available.” It was now producing items of the highest quality, so that by the summer of 1881, over 600 people were employed in the complex. This was a period of great prosperity and expansion for the now thriving Woollen Mills, and while more employees were needed there was an urgent lack of housing to cater for the influx of workers to the locality. As there was a limit to the distance people could easily travel to work, Mahonys understood that if they could offer the people houses as well as jobs, there would be no difficulty attracting suitable labour. Martin Mahony & Bros., Ltd. Mills was by far the biggest manufacturing concern in the district, with people being employed from many parts of the wider catchment area, including Cork city. Many of these workers would spend most, if not all, of their working lives in the mill complex. With this in mind, the Mahonys began a period of house building to accommodate these workers.

Blarney Mill Houses and Portlaw 

The town of Portlaw, Co. Waterford, is a small town which stands on the Cladiagh River and is situated about 18.5 kilometres from Waterford City via the R680 to Carrick-on-Suir.

It was to this location that the Malcolmsons, a Quaker family were attracted about 1825, building a cotton mill of 7 storeys, of which 5 remain today, on a section of the river which was navigable for barges of about 20 tons.

Blarney village eventually appears to have been a relatively pleasing and pleasant place with its Village Green as a centre piece with houses and businesses located around its four sides. (See 1841 Map). This was basically the original lay-out envisaged by James St. John Jefferyes

There are a number of similarities between Portlaw and Blarney.

The village of Blarney stands on the River Martin and it was to here that the Mahony Brothers were attracted in 1823 when they were relocating their business from Blackpool in Cork city. They had a weir/dam constructed across the River Martin approximately 2 kilometres from the location of the mill buildings. This area became known locally as the ‘Big Pond’. A mill-race was then constructed which diverted water from the pond for general use in the mill and also to provide force to drive water wheels which in turn transferred power to various geared shafts for the mill operation.

Two single storey houses (both in ruins now) with ‘Portlaw Roofs’ and ‘Belfast Trusses were constructed at the Big Pond. The numbers 1 to 5 in St. Helen’s Row, Waterloo Road were all single-storied buildings but presently only No.1 (currently unoccupied) is the last remaining in its original state. Numbers 2 to 5 have had their roofs and ceilings raised in relatively recent years using modern roofing materials.

The Mahony houses were built primarily for the betterment of their workers. At the height of the Martin Mahony & Bros., woollen mills production it was said that there was in excess of 1,000 people employed in the factory. To ensure continued production, travel time needed to be cut for those from outside the area, and so a programme of house-building was begun to entice workers to move closer to their place of employment.

It was after the near disastrous fire of 1869, in which the factory was almost completely destroyed, that a new greatly enlarged building was constructed and went into full production thereby requiring an increase in staff numbers to meet vastly increasing new production requirements. Many people were attracted to Blarney with the new work opportunities and as they employed more people, Mahonys began a construction programme of over 100 terraced houses close to the mill location in the mid-1800s. The Mahony Brothers were excellent employers to their workers and rented the newly built houses to them at fair rates.

All of these houses appear to have had four rooms, a back and front door, and cast-iron fireplaces and ranges for cooking making the living quarters very comfortable, especially during winter-time.

This building development continued into the early 20th century and as a result, many other small businesses arrived in Blarney to serve the now growing population and avail of this newly generated wealth thanks to the Mahony’s enterprise. These were to include public houses, inns, lodging houses, traders and shopkeepers.

The Portlaw Roofs 

There was one very notable aspect to these houses, it being the shape of the roofs. They were known as ‘Portlaw Roofs’.

Several older members of the Mahony mill house community were of the opinion that the roofs were known as ‘Barrel Roofs’ and this belief appears to come from the ‘Bow’ design or shape of the roof. A ‘Barrel Roof’, while having a curved view on top outside, would also have had a curved or vaulted ceiling indoors to match, whereby the true ‘Belfast Roof’, while having a curved top outside, had a flat ceiling inside.

The roof structure is of a rather unusual configuration although it was a relatively popular construction in the mid to late 1800’s. It appears to have been invented in Belfast sometime around 1850 where it subsequently became known as a ‘Belfast Roof’. The trusses being known as ‘Belfast Trusses’ and were originally designed to be used with tarred roofing felt (sail cloth) which was laid on timber boards. These trusses could be assembled rather quickly and cheaply, often using what would be described as scrap wood. They were extremely efficient for spanning large, wide areas such as farm buildings with spans of between 6 m. and 36 m., creating the wide span and plenty of height that is needed for a high-ceilinged room and were used extensively for the roofs of the buildings in the Harland and Wolfe ship-building yards as well for the roofs of aircraft hangers where large work-areas with plenty of height were needed to be clear of obstructions. They were assembled so efficiently and worked so well, they were thought of as a perfect cheap solution to roofing houses and were used extensively throughout Ireland and Great Britain until about the 1930s. They were also to be found in areas across Europe but especially so in the Ruhr area of Germany before the Second World War. The speed of construction was due to the fact that the trusses were nailed and prepared on the ground and then hoisted up into position on the supporting walls. They were still being made in Lagos in the late 1950s. These roofs can still be seen in many places throughout Europe. In America, they were known as the ‘Build-Fast’ roof. While not exactly rare, they are not a popular roof for modern buildings, currently, but several hundred may still be found at various locations around Ireland, many in buildings of historical interest. It was vitally important that the correct levels were adhered to when the trusses were being put into place because if just a single truss was out of level, the outside roof materials would also be out, which, in turn, would cause stress to the tar-felt which kept the rain-water out and it would eventually crack, tear and leak causing water damage. These types of complaints have been experienced and corrected, using modern materials, in a number of local houses recently.

The above excerpt was taken from a much larger article titled ‘The Mill Houses of Blarney’ by Brian Gabriel and published in Issue No 12 ‘Old Blarney’ Journal. A limited number of ‘Old Blarney’ back issues are still available by contacting 087 2153216, or

Please keep checking the Web-site for up-to-date information and local articles.

Contact: Mr. Brian Gabriel Email: Tel: 087-2153216