The Japanese Association for Conservation of Architectural Monuments

Traditional Techniques

TRADITIONAL TECHNIQUES FOR CONSERVATION

The traditional techniques that are applied to the conservation of heritage buildings have been handed down from generation to generation by experienced craftspersons. Working day-to-day under skilled masters is essential for training such skilled workers. However, due to modernization of the Japanese lifestyle and building techniques, the demand for traditional work has decreased rapidly, and it is now difficult to maintain a sustainable business based on traditional techniques alone. In addition, the lack of young craftspersons, tools and toolmakers, and materials such as lacquer and straw, have become important challenges for their subsistence.

As a measure to ensure their continuation, these traditional techniques are designated by the Japanese Government as "Selected Conservation Techniques". Organizations that possess these techniques are recognized as "Holders of Selected Conservation Techniques", and receive aids to train new craftspersons.

Building Conservation

Heritage buildings in Japan include temples, shrines, castles, residences, and modern architecture. These buildings employ materials such as timber, stone, brick and reinforced concrete, and use different techniques depending on their region and their builders.

Architects working on the design and management of conservation and repair projects for these buildings must have a highly specialized knowledge of building and repair techniques. In addition, they must have a deep practical knowledge to be able to guide the work of carpenters and other craftspersons on site.

Carpentry (Architecture)

Traditional carpentry is the technique employed to repair heritage wooden buildings. As most heritage buildings in Japan are built in wood, it is an essential technique for heritage conservation. In order to repair a wooden building, it is necessary to understand its design and building techniques and select the repair method accordingly. Therefore, it is essential to ensure the continuation of the traditional knowledge of carpentry techniques.

Roofing: cypress bark (hiwada), shingles (kokera), thatch (kaya)

Vegetal materials such as cypress bark (hiwada), shingles (kokera), and thatch (kaya) have been traditionally employed for roofing heritage buildings in Japan. Hiwada and kokera are hand-cut shingles of cypress or cedar that are overlaid to cover the roof. Shingles are gathered and shaped by hand and fixed in place one by one with bamboo nails. Thatching employs the stalk of cogon grass, pampas grass, and sedge to cover the roof. It is a widely employed ancient technique with many regional variations.

Decorative Techniques for Buildings

Decorative techniques for buildings can be divided into lacquering, coloring, painting with tan (red pigment), and ornamental metal fittings. These techniques express the religious significance of the buildings and the ideas of their patrons.

Coloring techniques express the religious significance of the building through patterns, paintings and carvings.

Painting with tan has a protective effect on wooden members and also an aesthetic function.

Metal fittings were originally employed to protect the cut end of wooden members and give the final accent to the appearance of the building.

These techniques require a highly developed aesthetic sense and craftsmanship.

Coloring Techniques for Buildings

Since their construction during the Edo period (1603-1868) the temples and shrines of Nikko have been regularly repaired and maintained. As a result, the coloring techniques employed in these buildings have been handed down until today. Lacquer is employed as a foundation for the coloring, which is applied using natural pigments and traditional materials. Several traditional techniques, such as layered painting and oil painting, are employed for the repair and restoration of patterns and carvings.

Roofing: tiles

The technique of roofing with tiles has been handed down for over 1400 years since tiles were introduced in Japan from the Korean Peninsula. Concave and convex tiles are employed to cover the roof. In the second half of the Edo period (1603-1868), mixed tiles were also developed.

Concave and convex tiles are employed in heritage buildings such as temples and castles. However, due to modernization and the change of lifestyle, the demand for tiles has decreased. Traditional roofing with tiles has become an even more specialized technique.

Plastering (Japanese Style Wall)

Traditional Japanese architecture employs a timber frame to support the building. The frame is filled with walls.

The materials employed for the wall are local wood and soil. Many walls have a foundation made of strips of wood or bamboo weaved with rope and covered with mud. The finishing is made with plaster or colored earth. These techniques have been handed down until today from ancient times.

Walls that employ unique Japanese materials and crafts, applying traditional techniques from before the Meiji Restoration (1868) are called "Japanese Style Walls". Craftspersons who hold these techniques are called sakan.

Production of Screens

These are the techniques used to repair wooden doors, sliding screens and windows employed in traditional Japanese buildings. These elements have to perform their architectural function and at the same time they have a delicate aesthetic expression. Craftspersons repairing them must have a high level of skill acquired through experience.

Production of Tatami Mats

Japanese traditional tatami mats are made of tightly woven rice straw covered with rush grass and linen thread. Wooden strips are handsewed to the borders and bound with silk, linen or cotton cloth.

In religious architecture, cloth with decorative patterns is employed to bind the mats and it is important to align the design of each mat with the neighboring ones. The size of each mat is different, and binding them correctly is a highly specialized, painstaking operation.

Traditional mats have excellent permeability to moisture and high fire resistance, helping to protect heritage buildings from fungi and fires.