Roofing in Ireland

Ireland has a mild, very wet Atlantic climate with frequent strong winds, especially in the west. Roofs are almost always pitched, and resistance to wind-driven rain and storm uplift is the main design concern. The traditional roof of the countryside was thatch; slate took over in towns and on larger farmhouses in the 19th century, and concrete tiles and fibre-cement slates are now the usual coverings on new houses.

Climate and hazards

Storms crossing from the Atlantic make secure fixing of slates, tiles, ridges and verges the key detail. In exposed western districts, traditional thatched roofs were tied down with ropes weighted by stones or fixed to pegs in the walls. Modern practice follows British fixing methods: the UK code of practice BS 5534, which no longer accepts mortar alone for fixing ridges and verges, is widely used as a reference in Ireland. Wind loads are calculated to the Eurocodes with Irish national parameters.

Roofing history

Straw was among the commonest materials of traditional Irish building, and the whitewashed thatched cottage belongs to a very old vernacular tradition. Slate was imported from Wales: a small export trade in Welsh slate to Ireland existed by the late 16th century, and in 1713 fourteen shipments carried 415,000 slates to Dublin. North Wales later exported skilled quarrymen as well as slate. Irish quarries also produced roofing slate; slate from Valentia Island in County Kerry was supplied for the Houses of Parliament in London, and the quarry reopened in 1998.

Through the 19th and 20th centuries thatch declined sharply as slate, then corrugated iron and concrete tiles became cheaper and easier to obtain. Surviving thatched cottages are now mostly heritage properties or holiday homes.

Traditional and vernacular roofs

The traditional cottage was a long, narrow, single-storey building with thick stone or mud walls and a roof of timber couples (rafters) carrying thatch. Common thatching materials were oat, wheat or rye straw and, near rivers and lakes, water reed. Thatch was often laid over a base layer of sods and needs a steep pitch, generally about 45-55 degrees. Villages such as Kilmore Quay in County Wexford still have groups of thatched houses. Heritage grant schemes have been used to help owners re-thatch traditional cottages.

Roofing today

Natural slate, much of it imported from Spain, fibre-cement slates and interlocking concrete tiles are the common coverings on new Irish houses. Clay tiles are less traditional in Ireland than in England. Flat roofs on extensions and commercial buildings use bituminous and single-ply membranes, often with insulation above the deck.

Codes, standards and regulation

In the Republic of Ireland, roof construction is controlled by the Building Regulations and their Technical Guidance Documents. Northern Ireland, part of the United Kingdom, has its own Building Regulations. Irish Standards (I.S.) and European EN product standards apply to roofing products, and British Standards such as BS 5534 are commonly referred to for slating and tiling practice.

Industry

Tile and slate supply is dominated by international groups: BMI Group markets Redland roof tiles in the UK and Ireland. Valentia slate is one of the few domestic roofing stones still quarried.

Notable roofs

Ireland's notable roofs are mainly vernacular: the surviving thatched cottages of the south-east and west, and the slate roofs of Georgian Dublin and market towns.

Sources and gaps

National data on roof coverings, on the number of surviving thatched buildings and on Irish-language roofing terms: published information is limited.