Roofing in South Africa

South Africa has one of the most varied roofing landscapes in Africa. Corrugated iron and zinc sheet covers most homes, concrete and clay tiles dominate suburbs, and asbestos-cement sheets remain on many older houses. At the same time the country keeps a large, regulated thatching trade, which serves heritage homesteads, lodges and new houses, and is one of the few in Africa with a dedicated national thatch standard.

Climate and hazards

Climates range from the winter-rainfall Western Cape to the summer-thunderstorm interior plateau and the humid KwaZulu-Natal coast. Lightning is a specific concern for roofs, particularly thatch: the Thatchers Association of South Africa (TASA) guide requires lightning protection where the ground flash density mapped under SANS 10313 exceeds 7 flashes per square kilometre per year, or 3 where wire sways could act as conductors. Fire spread between thatched buildings is the other main hazard addressed by regulation.

Roofing history

Stone Age. Border Cave, a rock shelter in the Lebombo Mountains of KwaZulu-Natal near the Eswatini border, holds some of the oldest known evidence of people deliberately preparing places to rest. Layers dated about 227,000 to 179,000 years ago contain beds of grass (mainly Panicoideae), with sedges and leaves, laid near the back of the shelter; 48 bedding layers were identified, many with ash and charcoal showing repeated burning. The site shows people using a natural rock overhang as their roof long before any built shelter survives (see Border Cave).

Iron Age kingdoms. Mapungubwe, at the confluence of the Limpopo and Shashe rivers, was the centre of a kingdom between about 900 and 1300 CE, with three successive capitals and palace sites set apart from commoners' settlements. It was inscribed on the World Heritage List in 2003 (decision 27 COM 8C.30) for a core area of nearly 30,000 ha (74,000 acres). Later Bantu-speaking societies built round, thatched houses; Zulu homesteads used hemispherical grass-thatched dwellings, while Sotho, Tswana and Ndebele groups developed cone-on-cylinder houses with mud walls and conical thatch.

Colonial period. From the 17th century, Dutch settlers in the Cape built long whitewashed houses under steep thatch with plastered gables, the Cape Dutch style. In the 19th and 20th centuries corrugated galvanised iron spread across farms, mining towns and townships.

Modern era. Factory-made concrete tiles, profiled steel sheeting and asbestos-cement sheets became standard in the 20th century. Today, profiled sheets such as IBR (inverted box rib) and corrugated sheet are the common covering for low-cost housing, farm buildings and industrial roofs.

Traditional and vernacular roofs

• Zulu hemispherical dwelling (indlu): a frame of sapling arches (izintingo) covered in grass thatch in two layers, an inner insulating layer (umfuguzelo) and an outer layer (umxhebulo), tied down by ropes gathered into a top-knot (isiqongo). See Zulu beehive hut.
• Rondavel: cylindrical wall with a conical thatched roof of radial poles and ring purlins, widespread on the interior plateau.
• Southern Ndebele homestead: grass huts until the early 18th century, then mud-walled houses whose walls were painted; Ndebele terms include amakapa (roof), apokorwana (eaves overhang) and isidlogorwana (apex capping).
• Tswana and Pedi houses: thatched conical roofs (Tswana moteko) over mud-plastered walls, often with a verandah carried on posts.
• Cape Dutch homestead: steep thatch, often of Cape thatching reed, over H-shaped plans.

Roofing today

In the unweighted 2011 Census 10% sample file (about 1.19 million household records), the roof material is recorded as:

Roof material (H02A_ROOF)	Share of records
Corrugated iron/zinc	55.8%
Tile	20.3%
Asbestos	10.8%
Thatch/grass	6.9%
Cement block/concrete	2.8%
Wood	1.0%
Plastic, cardboard, wattle and daub, other	2.2%

Profiled steel sheet is made in South Africa in galvanised (Z150 to Z275), aluminium-zinc (AZ150) and pre-painted finishes. A typical IBR profile covers 686 mm (27 in) per sheet in thicknesses from 0.40 to 0.80 mm (0.016 to 0.031 in), with a minimum pitch of 5 degrees for roof slopes under 30 m (98 ft) long and 7.5 degrees for longer slopes.

Codes, standards and regulation

Building work falls under the National Building Regulations, whose deemed-to-satisfy rules are published as SANS 10400. Part L covers roofs: roof coverings, waterproofing of pitched roofs and drainage of flat roofs, with flat roofs typically laid to a fall of about 1:50. Part T covers fire protection. Under clause 4.12.2 of SANS 10400-T, thatched buildings with a roof area over 300 m² (3,230 sq ft), or closer than 4.5 m (14.8 ft) to a boundary, need additional fire-retardant measures. Thatch construction is specified in SANS 10407 (edition 2, 2015); see SANS 10407 thatched roof construction.

Industry

The Thatchers Association of South Africa publishes a construction guide and represents thatchers. Thatching materials include common and fine thatching grass (Hyparrhenia hirta, H. filipendula) and Cape thatching reed (Thamnochortus, Afrikaans dekriet). Steel roll-formers produce IBR and corrugated profiles; Clotan Steel is one documented producer of IBR sheet.

Notable roofs

• Mapungubwe Cultural Landscape (UNESCO 2003).
• Border Cave: rock-shelter "roof" of some of the oldest known grass bedding.
• Cape Dutch homesteads such as Groot Constantia, rebuilt after the 1925 fire.

Local roofing terms

• dekriet (Afrikaans): Cape thatching reed.
• indlu (isiZulu): dwelling; inca / utshani: grass; isiqongo: thatch top-knot.
• moteko (Setswana): thatched roof covering; setlhowa: apex of a conical roof; maribele: eaves.
• amakapa (isiNdebele): roof.
• IBR: inverted box rib steel sheet.

Sources and gaps

Census shares are unweighted counts of records in the 10% sample file, not official population estimates. Published Census 2022 roof tables, figures for roofs in RDP (state-subsidised) housing and national production data for tiles and sheeting: published information is limited.