Roofing in Burundi

Burundi is a small, hilly and densely settled country on the north-east shore of Lake Tanganyika. Its traditional house, the rugo, was a round, dome-shaped building made entirely of plant materials: a frame of poles bent into a dome, bound with rings of reed and papyrus and covered with thick straw thatch. The finest examples, the royal huts (ingoro), reached about 10 m (33 ft) across. The rugo of the Mugamba highlands is on Burundi's tentative list for World Heritage status.

Climate and hazards

The climate is tropical but tempered by altitude, with distinct rainy and dry seasons. Moisture is the main enemy of traditional straw roofs; traditional houses were sited mid-slope, with doors oriented with regard to the prevailing easterly winds, and roofs were sloped to shed rain.

Roofing history

Traditional building knowledge is documented mainly through the rugo of the Mugamba region and reconstructions in museums. Building was a communal task: a household head called on relatives, friends and neighbours, typically 20 to 30 people, who worked in two teams on the roof and the exterior. Materials were collected across the rainy season, often from forests, and building took place in the dry season.

The measurements recorded in the 2018 study include a reconstructed hut displayed in a museum, and the rugo is treated today as a heritage form.

Traditional and vernacular roofs

The rugo. A typical house had a floor area of 20 to 28 m² (215 to 300 sq ft) and an average height of about 3 m (10 ft). Its radius reflected status: about 2.5 m (8 ft) for a young household, about 3 m for a large or wealthy family, and up to 5 m (16 ft) for chiefs. Diameter was set out with a body measure (intambwe): a man lying on the ground with his arm outstretched.

Construction, as recorded in a 2018 study of Burundian traditional architecture:

1. Some 45 to 60 piles about 2 m (6.6 ft) high were set 30 to 40 cm (12 to 16 in) apart, dug 50 to 60 cm deep.
2. Between 120 and 200 bent poles about 4 m (13 ft) long formed the dome, tied with horizontal rings of reed core wrapped in papyrus.
3. Inside, 8 to 13 pillars with carved, hoof-shaped ends supported the dome, and a spiral coil (umutente), about 200 m long, was built into the roof.
4. The outer poles were folded together at about 3 m to close the dome (guheta).
5. Walls were woven of split bamboo, the hut was thatched with straw, and a door frame, lintels and a roof topknot finished the work.

The inner face of the roof (igisenge) was lined with palm reed or papyrus. Damaged straw had to be replaced regularly, by one account twice a year, and old straw was reused as fertiliser.

The royal hut (ingoro) measured about 10 m (33 ft) in outside diameter and 4 m (13 ft) high, with thatch about 90 cm (3 ft) thick; a papyrus mat once covered its thatch.

The compound. The rugo complex was enclosed by a bamboo fence and divided into a front courtyard (urugo) used as a livestock park and a rear courtyard (ikigo), with smaller dwellings for family members.

Roofing today

Burundi's 2016-17 Demographic and Health Survey (EDSB-III) recorded the main roof material of each household, using categories from thatch and palm leaf through metal, calamine and cement fibre, ceramic tiles and cement.

Notable roofs

• Traditional rugo of Mugamba: added to Burundi's UNESCO tentative list on 9 May 2007.
• Museum reconstruction of a traditional hut, documented in the 2018 study.

Local roofing terms

• rugo (Kirundi): house or housing complex.
• ingoro: the king's hut.
• igisenge: the inner part of the roof.
• umutente: spiral coil inside the dome.
• guheta: folding the poles together to form the dome.
• intambwe: body-based unit of measure.

Sources and gaps

Results of the EDSB-III roof-material question: published information is limited.

National roofing statistics for Burundi were not found, so the present-day mix of metal sheet, tile and thatch is not quantified. The grass species used for straw thatch were not named in the sources. Building codes, standards and industry: published information is limited.