Portlaw lies on the River Clodiagh 20 km north-west of Waterford. It developed as an industrial community from 1825 when property in the vicinity was bought by David Malcolmson (1765-1844) a Quaker, descended from Scots who migrated to Ireland in the 17th century, who had prospered by working corn mills in Clonmell and elsewhere, and was the founder of an industrial dynasty.
Malcolmson’s property included a small corn mill which he replaced with a cotton factory, 79 m long and 12 m wide. The mill was of six storeys, and originally of 13 bays, with a crenellated parapet. An extension of 15 bays was built at the northern end in 1837-33. Malcolmson completely rebuilt the water-power system, providing a 4.2 m fall, and installed four waterwheels, two of which were of iron, 9.7 m in diameter. A large single-storey weaving shed, with half its roof of glass, was built on the opposite side of the river, and linked with the rest of the premises by two iron bridges. He also established a canal connection with the River Suir which enabled 60-tonne barges to reach Portlaw from the port of Waterford. A gasworks was operating by 1841, and a small engineering works, the Mayfield Foundry was established within the complex.
At its peak the mill employed up to 2,000 people. David Malcolmson built some houses for his workpeople from 1825, and more were added in the 1830s, but the celebrated industrial community of Portlaw was laid out in the time of his sons in the 1850s, possibly by the architect John Skipton Mulvany (1813-70), well-known as the designer of some of the most elegant Irish railway stations. Both the houses and the layout are unusual. The community is planned in the Baroque manner as a polyvium, with triangular blocks of buildings, the apex of each meeting in a central square from which a boulevard, Factory Road, runs to the mill. Many of the houses have characteristic Portlaw roofs, made up of gently curving lightweight wooden trusses covered with tarred calico.
A few houses of similar design were built at other industrial communities in Ireland, including Bessbrook and Blarney, and some at Gelsenkirchen in the Ruhrgebiet, where one of the leading mining entrepreneurs was William Thomas Mulvany (1806-80), brother of the architect.
The fortunes of the extensive Malcolmson enterprise faltered in the 1860s, following difficulties caused by the American Civil War and the collapse of the Overend Gurney bank in 1866. The company was liquidated in 1876 and the mill closed with the loss of some 1,141 jobs. Some small-scale textile production was revived until 1904, and a creamery was located in the building until 1914.
In 1932, when the government of Ireland was striving for economic self-sufficiency, the largest tannery in Ireland was established on the mill site, for which a substantial concrete building was erected in 1945. The tannery closed in 1985 and the site, which includes the ruins of the cotton mill, awaits re-development. The Malcolmsons’ housing remains and there have been several local heritage initiatives in recent years.