When making an ondol floor, clay is laid over a base of flat rock, and a fuel hole for a fire is made on one side and a chimney is made on the other.

• 做房间地板的时候，放上宽而扁平的石头，在那上面平坦地覆盖上粘土，然后在一边做上可以烧火的灶口，反面做上烟筒。