Roofing in Cambodia

Cambodia's roofing story spans the stone and brick temples of the Angkorian empire, the timber halls and houses that once stood around them, and a modern housing stock in which galvanised metal sheet and clay tile have almost entirely replaced thatch within a generation.

Climate and hazards

Cambodia has a tropical monsoon climate with a long, very wet rainy season, high heat and humidity, and widespread seasonal flooding around the Mekong and the Tonle Sap lake. Roofs must shed heavy rain fast and shade walls; houses in flood areas are raised on posts.

Roofing history

Angkorian temples (9th-15th centuries). The earliest Angkorian temples, such as the towers of Preah Ko, Lolei and Bakong (dedicated 881), were built mainly of brick. Ta Keo in the 10th century was the first temple built almost entirely of sandstone, which came from the Kulen hills; laterite was used for foundations and hidden structure.

Khmer builders never used the true arch. Rooms, passages and galleries were spanned with lintels or with corbelling, in which each course of stone projects slightly beyond the one below until the two sides meet. Corbelling limited the width of stone-roofed spaces, and corbelled roofs tend to collapse once a building is neglected; preventing this remains a conservation challenge at Angkor. Builders sometimes avoided the problem by topping stone walls with a light timber roof.

Art historians divide the period into styles, including Kulen (825-875), Preah Ko (877-886), Bakheng (889-923), Angkor Wat (1080-1175) and Bayon (1181-1243).

Timber and tile. Palaces and ordinary buildings were made of wood and have not survived. A 13th-century Chinese account describes palace buildings crowned with lead-tiled roofs. Bas-reliefs at the Bayon and Banteay Chhmar show timber buildings with triangular gables and double-tiered roofs. Late 12th-century "halls of dancers" at Ta Prohm, Preah Khan and other temples originally had perishable roofs, of which only the stone walls remain.

Post-Angkor. As Theravada Buddhism spread, timber architecture became the norm for temples. The steep gabled and multi-tiered roofs seen in the Bayon reliefs are still used on Khmer palaces and pagodas, for example Wat Botum in Phnom Penh.

Traditional and vernacular roofs

The rural Khmer house has a timber frame raised on posts and a steep gabled roof, traditionally thatched, with deep overhangs that keep rain off the walls. Pagoda and palace roofs are typically double-tiered and steeply gabled, a form already shown in the Angkorian reliefs of the Bayon. Carved gable boards on Khmer buildings belong to a wider regional family that includes Thai, Lao and Malay houses.

Roofing today

Cambodia's Socio-Economic Survey (CSES) tracks roof materials of occupied dwellings. Between 2004 and 2013 the share with "hard" roofs rose from 71.3% to 93.5%, while thatch fell from 21.4% to 6.1%. In 2013 the national breakdown was:

• Galvanised iron or aluminium: 53.7%
• Clay tiles: 26.0%
• Fibre cement: 9.3%
• Concrete: 4.3%
• Thatch: 6.1%

Concrete roofs are concentrated in Phnom Penh (32.2% of dwellings in 2013, against 0.2% in rural areas), reflecting flat-roofed shophouses and apartment buildings. In rural areas tile (28.8%) and metal (53.5%) dominate, and thatch remained on 7.7% of rural dwellings in 2013.

Industry

Clay tile production and roll-forming of metal sheet are both established, but no manufacturer or association data was found.

Notable roofs

• Angkor (UNESCO World Heritage): stone corbel-vaulted galleries and towers, notably Angkor Wat and the Bayon.
• Royal Palace and pagodas of Phnom Penh: multi-tiered tiled roofs descended from the forms shown in Angkorian reliefs.

Sources and gaps

Building-code and industry information and a glossary of Khmer roofing terms: published information is limited.