Roofing Materials
- Asbestos-Cement RoofingRoof sheets and slates made of cement reinforced with asbestos fibres, widely used in the 20th century and now banned in many countries as a health hazard.
- Bamboo RoofingRoofs built with bamboo, either as split culms laid like interlocking half-pipes or as a frame for thatch and other coverings, common in tropical Asia and Latin America.
- Clay Roof TileA roofing unit moulded or extruded from clay and fired in a kiln; one of the oldest and most widespread roof coverings in the world.
- Glazed Roof TileA clay roof tile coated with a glassy glaze before firing, giving a glossy, coloured surface; prominent in East Asian and some European architecture.
- Natural SlateA fine-grained metamorphic rock split into thin, durable roofing units; among the longest-lasting roof coverings in use.
- ThatchA roof covering of dry plant stems such as reed, straw, sedge, palm or grass, laid thickly so rain runs off the outer layer.
- Wood ShingleA thin, tapered piece of wood, sawn on both faces, laid in overlapping courses as a roof or wall covering.
Roof Components
- Rain ChainA rain chain is a chain or series of linked cups hung from a gutter outlet that guides rainwater to the ground as a decorative alternative to a downspout.
- Snow Guards and Snow RetentionSnow guards are devices fixed to a roof to hold or break up snow and ice so it does not slide off in dangerous slabs; they are especially common on metal roofs.
Roof Shapes & Forms
- Irimoya (East Asian Hip-and-Gable Roof)Irimoya is the Japanese hip-and-gable roof: a hip roof whose upper part rises into gables on two sides, known as xieshan in China and paljak in Korea.
- Pagoda RoofA pagoda roof is the stacked series of projecting eaves on a tiered tower, typically an odd number of tiers, found across East, Southeast and South Asia.
Installation & Methods
- Cold Weather RoofingCold weather roofing covers the extra precautions needed below normal application temperatures, from warming materials to hand-sealing shingles.
- Ice Barrier InstallationAn ice barrier is a self-adhering membrane or cemented underlayment installed at the eaves to resist water backing up under shingles from ice dams.
Standards, Codes & Testing
Manufacturers
History of Roofing
- Asuka-deraJapan's first full Buddhist temple complex, begun in 588 with Baekje craftsmen; the first building in Japan known to have used fired roof tiles.
- Banpo HousesSemi-subterranean round houses with steep, overhanging thatched roofs at Banpo, a Yangshao culture village near Xi'an, China, about 4700-3600 BCE.
- Beijing National StadiumThe 'Bird's Nest' stadium for the 2008 Beijing Olympics, whose roof and facade form a single lattice of about 121,000 tons of steel.
- Chinese Glazed Roof TilesGlazed ceramic roof tiles in imperial yellow, green, blue and other colours, used on Chinese palaces and temples to signal rank.
- Chinese Imperial Roof FiguresGlazed ceramic statuettes marching along the ridges of Chinese imperial buildings; their number signalled the building's rank.
- ChiwenChiwen are dragon-like ornaments at the ends of Chinese roof ridges, descended from the Han-period chiwei and believed to protect buildings from fire.
- DougongDougong are interlocking timber bracket sets of blocks and arms that carry the roof and deep eaves of traditional Chinese and East Asian halls.
- Earliest Fired Clay Roof TilesThe oldest known fired clay roof tiles: Neolithic pan and cover tiles from Qiaocun, China, and early flat tiles from mainland Greece.
- Foguang Temple East HallThe East Hall of Foguang Temple, Shanxi, completed in 857, is one of China's oldest timber halls, with a hipped tiled roof on Tang bracket sets.
- Hemudu Stilt HousesRaised timber houses of the Hemudu culture of Zhejiang, China, about 7,000 years old, with the earliest known Chinese mortise-and-tenon joints.
- History of Japanese KawaraHow fired clay roof tiles (kawara) arrived in Japan with Buddhism in 588 and spread from temples to palaces, castles and ordinary houses.
- History of Korean GiwaGiwa are Korean fired clay roof tiles, introduced with Buddhism in the 4th century and refined in the Three Kingdoms period with lotus-pattern roof-end tiles.
- History of Roofing Fire RegulationsHow urban fires led cities to ban thatch and wood roofs, from London in 1212 to Boston in 1631 and 1872 and the US push against wood shingles in 1916.
- Jomon Pit DwellingsSemi-sunken houses of Japan's Jomon period, with post-supported roofs of thatch or packed earth, best known from Sannai-Maruyama and Goshono.
- Roofs of the Forbidden CityThe yellow-glazed tiled roofs of Beijing's imperial palace, built 1406-1420, whose colours, forms and ridge figures encode imperial rank.
- Yingzao FashiThe Yingzao Fashi is a Chinese building manual by Li Jie, published in 1103, that standardised timber framing, bracketing, tiling and glazes.
Roofing Around the World
- ChogaChoga is the Korean thatched house and its rice-straw roof, renewed every one to three years and once the home of most Korean working people.
- Fujian Tulou RoofsTiled roofs with wide overhanging eaves that crown the circular and square earthen tulou of Fujian, China; a UNESCO World Heritage site.
- Gassho-zukuriSteep thatched farmhouse roofs of Shirakawa-go and Gokayama, Japan, shaped to shed heavy snow; part of a UNESCO World Heritage site.
- Ger RoofThe ger roof is the domed roof of the Mongolian yurt: straight uni poles rising to a wooden toono crown ring, covered with layers of felt and canvas.
- Hanok Roof (Giwa and Choga)Roofs of the traditional Korean house: curved clay-tile giwa roofs of the upper classes and rice-straw choga thatch of rural commoners.
- HiwadabukiHiwadabuki is Japanese roofing made of many thin layers of hinoki cypress bark fixed with bamboo nails, used on shrines, palaces and temples.
- Japanese Kawara TileFired clay roof tiles of Japan, used on temples since Buddhism's arrival and on houses since the Edo period, made in centres such as Sanshu and Sekishu.
- KayabukiKayabuki is Japanese grass thatch, usually miscanthus or reed, used on farmhouses, shrines and the steep gassho-zukuri roofs of Shirakawa-go.
- KokerabukiKokerabuki is a Japanese roof of very thin split cypress shingles, a few millimetres thick, fixed in close courses with bamboo nails.
- Roofing in ChinaChinese roofing from the earliest known composite tiled roofs (c. 2400-2200 BCE) through ranked imperial tile roofs to concrete and steel today.
- Roofing in Hong KongHong Kong roofing: tiled roofs of walled villages and early tenements, replaced by flat concrete roofs on dense high-rises designed for typhoon winds.
- Roofing in JapanJapanese roofing: kayabuki thatch, cypress-bark and shingle temple roofs and kawara clay tile, now joined by lighter metal and slate for earthquakes.
- Roofing in MongoliaMongolian roofing centres on the felt-covered ger with its crown ring and radiating poles, alongside concrete and panel buildings in Ulaanbaatar.
- Roofing in North KoreaNorth Korean roofing shares the Korean giwa tile and choga thatch tradition; modern Pyongyang mixes concrete flat roofs with monumental tiled roofs.
- Roofing in South KoreaSouth Korean roofing: giwa clay tiles and choga rice-straw thatch, replaced from the 1970s by slate and concrete, with flat roofs on today's apartment towers.
- Roofing in TaiwanTaiwanese roofing: Indigenous stone-slab and thatch houses, Hokkien swallowtail-ridge temples, then concrete roofs topped by countless steel rooftop additions.
- Siheyuan RoofRidged, tiled roofs of the siheyuan courtyard houses of Beijing and northern China, with curved eaves and a south-facing main hall.
- Swallowtail RoofA swallowtail roof has a main ridge whose ends sweep up and split like a swallow's tail, typical of Hokkien temples and mansions in Fujian and Taiwan.
Climate, Hazards & Sustainability
- Earthquakes and RoofsHow roof weight, attachment and bracing affect building performance in earthquakes, and why heavy tile roofs on weak frames are a known risk.
- Freeze-Thaw DamageCracking, spalling and flaking of porous roofing materials caused by water freezing and thawing repeatedly inside pores and cracks.
- Green RoofA roof partly or fully covered with vegetation and growing medium over a waterproofing membrane, used for stormwater, cooling and habitat.
- Hail Damage to RoofsDamage caused when hailstones strike roofing: bruising and granule loss on shingles, cracked tiles and slates, dented metal and punctured membranes.
- Hurricane Roof DamageHow tropical cyclones (hurricanes, typhoons and cyclones) damage roofs, from lost coverings and edges to deck blow-off and wind-driven rain.
- Ice DamA ridge of ice that forms at the eaves of a snow-covered roof and traps meltwater, which can then back up under the roofing and leak.
- Snow LoadThe weight of accumulated snow and ice that a roof must be designed to carry, derived from local ground snow data and roof shape.
- Snow Sliding and Snow GuardsThe sudden release of snow and ice from a sloped roof, and the guards and rails installed to break it up and hold it in place.
Problems, Repair & Maintenance
- Korean Asbestos Slate RoofsAsbestos-cement slate roofs spread across rural South Korea from the 1970s; since 2011 local governments subsidise their removal and replacement.
- Thatch Maintenance and DecayThe care cycle of a thatched roof, including periodic ridge replacement, patching, and eventual rethatching as the coatwork wears away.