Maintenance of a building can be divided roughly into the following three categories: cleaning, repair, and reinforcement. The town government was responsible for cleaning the main street and around the periphery of the island, the public park (the courtyard of building No. 65) and the main drains, and the company for the high central part of the island. Cleaning of the common space in each building was allotted to the residents according to a daily rota. On Sundays, they washed the wooden handrails of corridors and terraces to prevent them from rotting. Besides this, voluntary cleaning was willingly undertaken. According to “Shima”, (which means “island”), the magazine published on the island, on every second and fourth Sunday in the month, all senior high school students cleaned the island.

Many sorts of work, from replacing a window pane or a light bulb to the repair of the reinforced concrete structure fall into the category of repairs and these the company dealt with quickly and efficiently as soon as the residents had taken the necessary steps to inform them. In some cases, the residents themselves undertook the repairs using their own skills.

It is difficult to distinguish between reinforcement and repair, but the former is used here to mean not the repair of a damaged part or a part in danger of being damaged but the strengthening or buttressing of a weakened member using additional props and reinforcing members. They used the same techniques and material as were employed to secure the tunnels in the mine including pit-props etc.