Talking about the roofs of Japanese houses, kawara (ceramic roofing tiles) are by far the best.
Currently, kawara (ceramic roofing tiles) are once again attracting much attention in Japan.
About 50% of all roof tiles on Japanese houses are kawara. kawara, made of natural material, are fired in a kiln prior to becoming a final product. Ceramic roofing tiles have been used on Japanese houses since ancient times, beginning around 1,400 years ago. Besides being a traditional roofing material, kawara have continuously evolved to possess new, fundamental characteristics, such as highly waterproof performance, unique design and outstanding durability. Excellent new additional features have recently been added, such as a fixed structure that can withstand earthquakes and typhoons, and a heat-insulation capability based on reflection of sunlight.
In order to produce kawara, several kinds of clay are first mixed and kneaded, then, shaped and dried. Next, green bodies are glazed and calcined to become final products. Because kawara are fired at a high temperature of 1,130 degrees Celsius, they are highly durable as roofing materials, even though the roof must endure the severest weather conditions and protect the house for a long period of time. As they are fired in a kiln, ceramic roofing tiles are designated by the Building Standards Act as non-combustible material and, therefore, they do not need undergo any verification tests for non-combustible material. Unlike slate roofing material, kawara do not use any asbestos as a raw material, which further guarantees the safety of the material for human use.
In the past, kawara sometimes required repair work, due to their susceptibility to damage caused by natural disasters, such as earthquakes or typhoons. Nowadays, however, disaster-resistant kawara have been developed, and roofing methods have also been improved, making kawara a very safe and dependable roofing material.
What are Sanshu-kawara of Aichi Prefecture?
Sanshu-kawara are one of Japan’s three greatest clay products. Aichi is the largest producer of kawara in Japan.
Sanshu-kawara (sanshu roofing tiles) are produced in the western Mikawa district (formerly called Sanshu region) of Aichi Prefecture.
The Sanshu region has the following advantages:
1. This region has abundant high-quality clay to be used as a raw material;"
2. This region is geographically located in the center of Japan and is also in one of Japan’s largest industrial areas. This greatly helps to reduce transportation costs by utilizing delivery trucks to carry freight between industrial areas.
3. Many raw materials and equipment suppliers are located in this region.
Thanks to these three factors, this region has become the most successful and prosperous producer of kawara in all of Japan.
Sanshu-kawara, together with Sekishu-kawara from Shimane Prefecture and Awaji-kawara from Hyogo Prefecture, are very popular nationwide and are called Japan’s three greatest clay products.
Sanshu-kawara possess 75% of market share in Japan.
Because of these suitable conditions for clay manufacturing, Sanshu-kawara have achieved a great reputation for excellent design, quality and the wide range of roofing materials available. Currently, Sanshu roof tiles have been highly evaluated nationwide and have gained 75% market share in Japan.