Roofing in Sierra Leone

Sierra Leone lies on the wet Atlantic coast of West Africa, and its roofs must above all shed heavy rain. Rural houses were traditionally thatched over earth or wattle walls, while Freetown developed a distinctive timber architecture brought by settlers from North America. Today corrugated metal sheet, locally called "zinc", covers more than four in five homes.

Climate and hazards

The climate is tropical and monsoonal, with a long and very wet rainy season and a shorter dry season brought by the harmattan. Persistent damp encourages rot and insect attack in timber and thatch, and many older roofs are patched with metal sheets to keep out the rain.

Roofing history

Freetown was settled from 1792 by Black Loyalists who had fought for the British in the American Revolutionary War and been evacuated to Nova Scotia, followed by Jamaican Maroons and Africans freed from slave ships. Their descendants, the Krio, built timber "board houses" that researchers link to cabin-like houses of the American eastern seaboard. In the early 20th century British officials moved to Hill Station above the city, building large timber houses on metal stilts set in concrete piles.

Over the 20th century stone and concrete houses became more fashionable in Freetown, and metal sheet became the usual roof across the country. In the 1991-2002 civil war, hundreds of wooden Krio houses were burned.

Traditional and vernacular roofs

• Thatch: grass or palm-leaf thatch is the traditional rural roof and is still recorded on about one household in seven.
• Krio board house (bod os): two-storey timber houses, sometimes with a garret, now often patched with metal sheet (see Krio board house).

Roofing today

In the unweighted 2017 Multiple Indicator Cluster Survey sample (about 15,300 households):

Main roof material	Share of sampled households
Metal, tin or corrugated iron sheets ("zinc")	83.8%
Thatch or palm leaf	13.5%
Palm or bamboo	1.1%
Cement	0.8%

A 2010 community-level agricultural survey asked how many rooftops in each community were zinc: in 43.1% of about 900 communities "most" were and in 15.8% "all" were, while 4.7% had none.

The 2015 Population and Housing Census classified roofs as concrete, asbestos, zinc, thatch, tarpaulin, tiles or other.

Notable roofs

• Krio board houses of Freetown, in neighbourhoods such as Kroo Town, Congo Town, King Tom, Fourah Bay and Murray Town; the Sierra Leone National Museum has called for their urgent conservation.
• Hill Station colonial timber houses on stilts.

Local roofing terms

• zinc (Krio and Sierra Leonean English): corrugated metal roof sheet.
• bod os (Krio): board house, the traditional timber house of Freetown.

Sources and gaps

Survey figures are unweighted counts. Detailed published sources on rural thatching techniques, regulation and industry: published information is limited.