Chinese Architecture: Roofs and Bracketing

Ronaldo Deluna, Elika Etemad, Juan Rosario, Kimberly Tanz
MARCH-631 History 1: Ancient to Medieval / Fall 2016

Traditional Chinese Timber Frames and Dou-Gong Bracketing

China has a long history of heavy timber frame construction, from prehistoric times onward. While the combination of timber framing and rammed earth walls were common in the Han dynasty (200-25AD) and earlier, later construction tended to use pure timber structures. Two main forms of framing were developed: the tailiang system, in which the roof was supported by a stacked series of cross-beams raised upon each other by struts, and the chuandou system, in which the roof is supported by increasingly taller columns stabilized by tie-beams.

Since the walls in such construction were not load-bearing, this led to the need for sophisticated joinery techniques to support the roof, and hence the development of the dou-gong bracketing system. Dou-gong bracketing used wooden bearing blocks (dou) and bow-shaped brackets (gong) to distribute the load of the roof across beams, and to connect beams to columns. It reduced spans, increased the strength of these moment connections, and absorbed shock from wind and seismic activity. Dou-gong bracketing allowed the connection of multiple beams, potentially at varying angles, to the same column. Over time these brackets and their joinery became increasingly complicated and increasingly decorated, signifying the wealth and importance of the building and its owner. Colorful lacquer and paintings embellished palaces while protecting the wood from water.

Owing to the strength and flexibility of the dou-gong system, it has persisted across millenia. The earliest references to dou-gong bracketing date from the Zhou Dynasty (1100-256 BCE), and it was in use in China through the 19th century when modern Western technology was introduced. Because it does not rely on load-bearing walls, and because it allows connections at many different angles, it allows for great flexibility in programming and has been able to accommodate architectural changes across a vast span of time and geographic climate. Because the connections are made with wood joinery and dowelling, they are able to withstand the dynamic loads from storms and earthquakes without damage to the structure. The system allows for wide eaves to protect against rain and damp, and it allows multi-storey construction, resulting in some of the tallest wooden structures in the world, some of which, like the Sakyamuni Pagoda, are still standing nearly a millenium later.

Traditional Chinese Roofs

Roof Shapes

Because Chinese timber frames create independently stepped supports for the roof, and their rafters are laid only across a single bay (jian) at a time rather than directly from ridge to eave as in Western construction, this allows for variation in the slope of the roof. The classic upturned curve of the Chinese roof is due to several considerations. It increases the amount of light for the same rain protection; it helps to hold the shingles together; and it optimizes the flow of water, being more steeply pitched at the start of the slope where more gravity is needed and more shallowly pitched where the increased accumulation and momentum of the water helps the roof to shed water. These curves were sometimes further exaggerated for aesthetic effect.

While the simplest Chinese roofs are single-sloped, gable roofs, hipped roofs, and various combinations thereof have created a rich vocabulary of traditional Chinese roof styles. Basic forms include the shed roof, the gabled roof, the hip roof, the pyramidal roof, and the gabled-hip roof, with the gabled roof being the most common and the hip roof considered the most illustrious (and in certain dynasties, reserved for imperial use). More elaborate buildings tier the eaves to create more complex architectural forms and to improve ventilation.

Roof Materials

Though thatch, mud, and wood and stone shingles have also been used for roofing in China, tiled roofs are among the most iconic aspects of classical Chinese architecture, and have been in use since at least the Shang Dynasty in the 2nd millenium BC. At the low end, simple unpainted clay tiles protect the multitude of common buildings. At the higher end, tiles are molded and imprinted with elaborate designs and painted and glazed with bright colors. Though flat tiles also exist, most Chinese roof tiles are cylindrical sections, and Chinese roofs exhibit variety of tiling patterns that exploit their concave and convex surfaces to create corrugated channels for shedding water. At the edges of the roof, specialized eave tiles were developed to improve the channelling of water, and subsequently developed their own highly ornamental designs. Additional ornamentation developed on the roof’s ridgeline, serving not only to embellish, but also to hold down the tiles at the top.

Below the tiles, the substructure adapted to its environment: in northern buildings, tiles were laid on a bed of clay and lime mortar, supported by a subroof of matting, whereas in southern buildings they were laid directly on purlins to increase ventilation. Both cases, however, necessitated a strong supporting structure, as the tile roofs were very heavy; and thus the timber frame and dou-gong bracketing were employed to hold up the heavyweight roof.

Guang

A guang is a wine-pouring vessel that was used for Chinese religious ceremonies. Before the Shang Dynasty (13th-11th century BCE), wine-pouring vessels were made out of clay but as bronze technology developed began to be cast out of bronze. There were many types of wine-pouring vessels in use, but for it to be classified a guang, the vessel must have had a lid at the top. The imagery of these vessels would often depict animals that were believed to represent Shamanic ideals and powers.

The trend of burying bronze vessels became a status of wealth throughout the Shang dynasty. Extravagant tombs, such as the ones excavated near Pingshan, Hebei Province, were modeled to look like palaces. The highly furnished and decorated tombs were multilevel in construction.

The burial traditions of the Shang Dynasty eventually laid a foundation that would soon be emulated by other tribes throughout China’s vast regions. Before the Shang dynasty, less expensive objects would be buried in tombs. Bronze vessels would often not accompany the dead in their tombs as the bronze would be reused and cast into other objects such as weaponry.

As with other symbols of wealth such the type of architecture employed, the artisanship of these wine-pouring vessels became more intricate in design. Mythical creatures, such as dragons, would often be cast at the front of the vessel. After the Zhou era, the use of the guang was short lived as a ceremonial apparatus as it fell out of favor with ceremonial practitioners. The use of the guang as a wine-pouring device soon changed into a water-pouring vessel and referred to as a “he”.

Chinese Pagodas

Overview

Pagodas are multi-layered religious structures designed to hold Buddhist relics and sacred writings. Inspired by northern Indian stupas and Chinese military watchtowers, pagodas are praised for their opportunity for scenic views from their upper levels.

Sakyamuni Pagoda at Fogong Monastery

Constructed in 1056 in Shanxi Province, Yingxian County, Sakyamuni Pagoda is referred to as “The First Pagoda.” It is not only one of the oldest surviving pagodas, but also one of the tallest wooden multi-storey structures in the world. It sits on a 13-foot base layer and with its 33-foot long steeple, stands at 220 feet. The building consists of ten structural tiers with alternating posts and cantilevered balconies, creating a total of nine stories.

While five distinct octagonal levels are visible, there are in fact four hidden levels that exist within the structure, indicated from the exterior by the terrace balconies. Sakyamuni Pagoda has interior and exterior support columns, as well as six intricately bracketed roofs composed of 54 different ceramic tile bracket arms. Overall the structure tapers to the center which contributes to stability and emphasizes the massive height.

Like most pagodas, Sakyamuni served as a temple where people could worship Buddha. The first level of the pagoda features a large Buddha statue situated in the center of the space. In addition, ornate caissons are painted on the ceiling of each level, signifying the level of craft at the time of construction.

The Sakyamuni Pagoda relates directly to to ancient Chinese architecture as it uses the iconic Dou Gong bracketing for structure. The brackets are used to connect roofs, floors and the columns of the following level, resulting in a multi-tiered building.

Ningbo Historic Museum

Opened on December 5th 2008, Ningbo Museum is a national first-level museum focusing on the history, culture, arts and traditional customs of Ningbo. In addition to the extensive use of building materials in the old brick, but also the use of bamboo and other elements of great Ningbo characteristics. Features of traditional Jiangnan residences are integrated into the museum design by decorations of the outer walls with old tiles and cement-covered bamboos. This sort of decoration itself was a common way of building an economical house in old days in Ningbo when cements are not introduced. Other walls are decorated with cement-covered bamboos.

The first floor of the museum is constructed as a whole part, while the building starts to tilt on the second floor, giving the whole building a mountain and also a boat shape. Permanent exhibitions are located on the second and third floor. The inspiration of the museum comes from mountains and ship, which are symbolic geographic features and representation of maritime trade that took pace through history. From the design of the program, Ningbo Museum of the building shape for the rectangle, like a ship in the sea. If you look up from the ground, its side is like a mountain.

Ningbo Historic Museum reflects back on the traditional Chinese roof structures through its use of roofing tiles as wall materials. The method of stacking the tiles to help with support is also relatable to the stacking of the Dou Gong bracketing.

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