Roofing in the Arctic and Greenland

Arctic regions, including Greenland, northern Scandinavia, Iceland, northern Russia, Alaska and northern Canada, impose some of the most demanding roofing conditions anywhere: extreme cold, long periods of snow cover, strong winds that drift snow, and short building seasons with materials shipped over long distances.

Traditional roofs

Indigenous and early settler buildings used what the land provided. Turf, stone and driftwood or imported timber formed low, heavily insulated houses whose turf roofs blended into the ground, as in the turf houses of Iceland and the turf roofs of Norway, which weighed around 250 kg/m² (51 lb/ft²) and could reach 400-500 kg/m² (82-102 lb/ft²) with winter snow.

Modern settlements

In Greenland, Danish policy after 1953 brought a major expansion of housing and infrastructure on Danish models, moving people from small settlements into towns. Large concrete blocks such as Blok P in Nuuk, once home to nearly 1% of the population, were later judged unsuitable and Blok P was demolished in 2012. Typical Arctic houses today are timber-framed or prefabricated, raised above permafrost where necessary, with pitched roofs of coated steel sheet or bituminous roofing, while larger buildings use membranes.

Snow loads

Roof design is governed by snow load. Codes convert mapped ground snow loads into roof loads, adjusting for exposure, thermal properties, roof shape, drifting and building importance; examples are ASCE 7 in the United States and Eurocode 1 Part 1-3 in Europe. Freshly settled snow has about 30% of the density of water, rising to about 50% by late spring, so a deep spring snowpack is far heavier than its depth suggests. Wind can build drifts several metres deep against parapets and roof steps.

Ice dams and condensation

On heated buildings with sloping roofs, heat escaping through the roof melts snow, and the meltwater refreezes at the cold eaves to form ice dams that can force water into the building. The remedies are high insulation levels, a ventilated "cold roof" kept below about -1 °C (30 °F), and waterproof membranes at the eaves. Airtight construction is also needed to stop warm, moist indoor air from condensing in cold roof spaces.

Practical concerns

Snow guards to stop sliding snow, robust fixings against wind, materials that remain flexible at very low temperatures, and designs that can be built quickly in a short summer season are typical Arctic priorities.