Dodai

A dodai is a timber sill, ground sill or footplate, used in traditional Japanese construction methods. Generally these are heavy timber members, 120mm or 105mm square and 4.0m in length, laid horizontally at the base of a wooden building upon which pillars or posts are then erected.

Occasionally, it is called a sill frame because it forms a grid pattern when laid on all four sides. If ground sills are provided under wall partitions, they are called partition majikiri dodai. In some small shrine buildings the footplates are laid directly on the ground and therefore timbers that are most resistant to termites and dampness are specified with species such as Japanese chestnut and cypress traditionally used.

Japan is one of the most heavily forested countries in the world, but since World War 2, has relied on imports for the bulk of their timber supply with traditional timbers now difficult to obtain.

In recent years many different timber species have been tried but because of the requirement for high durability and resistance to termites some have not been suitable. Treated timber, although acceptable for the purpose, is not preferred and Australian Cypress has become a favourite and is now accredited for use in the Japanese house building market.

Approximately 11% of the total Cypress timber supply in NSW is cut into dodai, and is therefore a major product of Cypress NSW. They are not usually available in Australia.