Roofing in Iceland

Iceland's roofing history is unusually compact: turf for about a thousand years, then corrugated iron, then reinforced concrete. Each shift reflected the island's scarcity of timber, its harsh North Atlantic weather and its earthquakes. Turf buildings survive in museums and on a few farms, and the turf house tradition is on Iceland's UNESCO Tentative List.

Climate and hazards

Iceland combines strong winds, frequent rain, repeated freeze-thaw and, in the north, snow. Roof design has to prioritise secure fixing against wind uplift, robust flashings and corrosion-resistant coatings in salty air. The island is seismically active, which is one reason reinforced concrete replaced turf and timber. Widespread geothermal heating keeps many buildings warm all winter, so insulation and ventilation of roof spaces matter for preventing condensation and snowmelt problems.

Roofing history

The vernacular tradition dates from the settlement of Iceland in the 9th century. The first houses were longhouses with a double-pitched roof running along the building, carried on freestanding interior posts and covered with turf. Native birch was the main framing wood, because oak did not grow on the island, and driftwood and imported timber were precious. From the Middle Ages to the 19th century the dominant form was the passage farmhouse, in which several turf-roofed rooms were linked by a central corridor. From around 1800 the gabled farm (burstabær) developed, with a row of timber gable fronts facing the yard and turf roofs behind.

In the late 19th and early 20th centuries, timber houses clad in corrugated galvanised iron (patented in Britain in 1829) spread through towns and farms; the material was light, easy to ship and could be fixed by semi-skilled builders. Iron also crept into turf buildings: at Núpsstaður, slates or corrugated iron lie beneath the turf, and some roofs use iron alone. Concrete became a main building material in the 1920s. A house at Sveinatunga in Borgarfjörður with cast-in-place concrete walls, built in 1895, is regarded as the first of its kind.

Traditional and vernacular roofs

Turf (torf) was cut from mineral-rich marshland in several standard shapes, named strengur, torfa, klömbruhnaus and snidda. The roof covering was turf laid over a timber structure, sometimes with additional layers beneath:

• At Keldur, slate roofs are covered with turf.
• At Þverá, dwarf birch is packed beneath the turf.
• At Tyrfingsstaðir, roofs are of driftwood and turf.
• At Bustarfell, tar paper has been used on some rear gables.

Turf roofs needed constant upkeep: walls and roofs settled, absorbed water and had to be rebuilt every few decades. See Icelandic turf house.

Roofing today

Most Icelandic buildings are of reinforced concrete. Pitched roofs on houses are commonly covered with corrugated or profiled metal sheet, and brightly painted corrugated roofs remain characteristic of Reykjavík and smaller towns. Larger buildings with flat and low-slope roofs use membranes.

Codes, standards and regulation

Building requirements are set by the Building Regulation No. 112/2012 (Byggingarreglugerð), which has been amended several times since 2012.

Industry

Most roofing materials are imported.

Notable roofs

The UNESCO Tentative List entry "The Turf House Tradition", submitted by the National Museum of Iceland in 2011, lists 14 sites, including:

• Glaumbær, Skagafjörður (mid-18th century to about 1880)
• Laufás, Eyjafjörður (mostly 1840-1877)
• Víðimýrarkirkja, a turf church built in 1834 on a site first recorded in 1318
• Hofskirkja, Öræfi, a turf church built in 1883-1885 on a site first recorded in 1343
• Keldur, Rangárvellir, with wooden features from the 17th century
• Árbær, Reykjavík, where three roofs are turf and three are corrugated iron

Local roofing terms

• torfbær - turf farmhouse
• torfþak - turf roof
• burstabær - gabled turf farmhouse
• strengur, torfa, klömbruhnaus, snidda - shapes of cut turf

Sources and gaps

Current market data on roof materials and information on domestic roofing manufacturers: published information is limited.