What Is Clay Roofing?
Clay tiles are a building material obtained by compressing and molding clay into the shape of a tile, drying it, and firing it at a high temperature of about 1,000 to 1,250°C (1,000 to 1,250°F).
They are also known as Japanese-style tiles. Clay tiles can be classified into three shapes: J-shaped Japanese-style tiles, S-shaped Spanish-style Western-style tiles, and F-shaped French-style Western-style tiles. Clay tile conditions include “glazed” tiles, which have a glazed surface, and “unglazed” tiles, which have no glaze on the surface, as well as “smoked” tiles, in which the surface of an unglazed tile is tarnished and covered with a film of carbon.
Clay tiles are durable and have excellent sound insulation and soundproofing properties. However, clay tiles are very heavy, weighing 3-4 kg per tile. Buildings using clay tiles may be at increased risk of collapse in the event of an earthquake.
Uses of Clay Roofing
Clay tiles have long been used in Japanese houses because of their suitability for the Japanese climate.
Among clay tiles, the “J-shaped” tile, which is a traditional shape, is often used for shrines, temples, castles, and tea rooms. F- and S-shaped tiles are used in a wide range of Western and Japanese-style homes.
Ibushi tiles are silver in color have a unique texture, and are often used in Japanese-style homes. One type of unglazed tile, the vermilion-colored clay tile called “unglazed tile,” is found in many Okinawan houses and is also available for use in European buildings.
Types of Clay Roofing
In terms of manufacturing classification, they are classified into three types: glazed, smoked, and unglazed tiles.
1. Glazed Tile
Glazed tiles are made by applying a glaze. Glaze is the paint of a baked product. A glassy glaze layer is formed on the surface of the tile, so many tiles are red, and glaze coloring is often only on the surface. Glazes can be used to express any color, and are mass-produced because of their ease of mass production and color control. Glazed tiles also include salt-fired tiles, which use salt instead of glaze.
2. Ibushi Tiles
Ibushi tiles have a carbon film formed on the tile’s surface by firing the unglazed tile and then tanning it with water or kerosene diluted with propane gas. The tiles have no front or back and are uniformly black. New tiles are uniformly black, but as the years go by, the color changes from black to silver, accentuating the roof.
3. Unglazed Tile
Unglazed tiles are tiles that are not glazed. There are unglazed tiles, kneaded tiles, and kiln-formed tiles. In unglazed tiles, the base material is baked. Kneaded tiles are made by kneading metal oxides into the raw clay. Kiln-altered tiles are intentionally fired in a special firing atmosphere.
How to Choose Clay Roofing
Tile roofs other than clay tiles require painting but do not require maintenance. Clay tiles have excellent sound insulation and heat insulation properties. Compared to slate and metal roofing, the main roofing materials used in recent years, clay tile roofing produces minimal sound. And tile roofs are warm in winter and cool in summer. It prevents the formation of condensation, which can cause the building to deteriorate because there is a layer of air that allows moisture to escape to the outside. Also, in case of partial deterioration due to cracks, etc., the tiles can be replaced one by one. In addition, clay tiles come in a wide variety of colors, are easy to work with, and are resistant to fading and color fading.
However, clay tiles are heavy and expensive per piece. As they deteriorate, they can develop moss and mold, which can be blown off by strong winds and typhoons.
Structure of Clay Roofing
1. J-Shaped Tile
The J-shaped tile is a traditional tile design. The motif is based on the traditional beauty of roof tiles developed by Japanese architecture, such as castles, temples and shrines, and tea rooms. It has a beautiful corrugated cross-section and is shaped to drain well when it rains.
2. S-Shaped Roof Tile
S-shaped tiles are Western-style tiles with an S-shaped curved cross-section. It is said that the name comes from the initial “S” of the word “Spanish” meaning Spain. Warm shades of reddish earth are often used. They are colorful and come in many variations of color.
3. F-Shape Tile
The F-shaped tile is a simple, square-shaped tile in the Western style. It has no corrugations is flat in design, and is called a flat tile. It is believed that the name comes from the “F” in “Flat” meaning flat. It can be used for both Western and Japanese-style houses. Recently, lightweight disaster-prevention tiles in the F shape have been made lighter and are often used.