Roofing in the Marshall Islands

The traditional Marshallese house was essentially a roof: a pandanus-thatched gable on four posts, with a loft in the roof space and often no walls. Modern housing on the atolls uses galvanised iron, aluminium or concrete roofs. Detailed ethnographic records of traditional construction exist from around 1900 onward.

Climate and hazards

The Marshall Islands are low coral atolls with a hot, humid climate. Rainfall is higher in the south than in the drier northern atolls, which affected how long thatch lasted. Fresh water is limited, and roofs serve as rain catchments.

Roofing history

Scholars classify the Marshallese house as a transitional form between a ground-level house and a pile dwelling. Its roof sat on four main posts rising about 1.3-2 m (4-6.5 ft) above a floor of coral gravel covered with mats. Two roof plates and two cross-beams formed the base of the roof and the floor of a loft reached through a hatch; this loft, used for sleeping and for storing valuable mats, was called im kidjerik ("rat house") because its smooth posts kept rats out. King posts carried the ridge pole, and paired rafters passed beneath it.

Thatch units were made from brown, fallen pandanus leaves wrapped around a stick and tied with coconut-leaf ribs, laid from the eaves up to the ridge, which was capped with old mats or woven coconut fronds. A roof was said to stay watertight for one to two years, longer on the drier northern islands. Around 1900 newer houses had plank floors, and by the 1910s some posts stood on large stones; walls were increasingly added after European contact and the arrival of Christianity. Cooking houses were thatched with coconut leaves and had no loft.

Traditional and vernacular roofs

• Im / iem: living house, with pandanus thatch and loft.
• Bellak: cookhouse, coconut-thatched.
• Bui: small raised hut for drying pandanus preserves.

Roofing today

The 2011 Census of Population and Housing recorded roof type in the categories galvanised/aluminium/tin, concrete, wood, fibreglass, thatch, and plastic or canvas tarpaulin. Imported metal sheet is the common modern roof.

Codes, standards and regulation

Building is regulated under the Planning and Zoning Act 1987, with a code first issued in 1987 and updated in 2021.

Local roofing terms

• Im kidjerik: loft, literally "rat house".
• Borwaj: ridge pole. Jur: post. Tur: cross-beam.

Sources and gaps

No domestic roofing manufacturers were identified.

Census percentages for roof materials and sources on cyclone or storm-surge damage to roofs: published information is limited.