Why are there pipes on the roof of Qingdao? Why are there two or three pipes standing on the roof of the house?

There are two kinds of pipes on the roof. One is a chimney, thick and short, which is connected with the fireplace or stove of the old building. The other is the exhaust pipe in the bathroom. The sewer pipe in the bathroom has odor volatilization, so when building a house, the sewer pipe is always connected to the roof, and a cover is added to prevent rainwater from flowing backwards to let the odor escape.

The old roof of Qingdao is inclined, so the pipes on the roof can see below. Most of the newly-built houses are flat-roofed, and there are no pipes on them downstairs.