What material is the kang in Northeast China made of?

The materials used in Northeast Kang are adobe, clay brick and cement board. The northeast kang was first made of adobe. The surface of the kang was covered with a certain thickness of soil, and there was a certain proportion of thatch in the soil. The kang surface has good thermal insulation performance, uniform temperature and lasting thermal insulation. The kang surface made of clay bricks has a special concrete slab, but the heat preservation and temperature uniformity of the kang surface are worse than that of the mud surface. Kang is very important, and it is an indispensable place in the daily life of Northeast people. If there is no health in the northeast folk houses, it is simply unimaginable. Northeasters used to eat three meals a day on the kang. There is a kang table on the kang when eating. People with status and status in the family sit cross-legged, usually men sit inside. The hostess is sitting on the edge of the kang, responsible for adding food and handing things to everyone, waiting for dinner. After school, the children also do their homework or play on the kang. People come and sit on the kang. Usually, every family has a cigarette basket, which contains tobacco leaves, cigarette paper and matches. When people come, they will push the cigarette basket in front of the guests sitting on the kang and say that they want to roll a cigarette, so everyone will smoke a cigarette. Dakang in Northeast China is an important stage of people's life in Northeast China before 1980s.