These are moss bars, which are found in many old houses, or on damp walls.

Tools and materials that need to be prepared for removal: sprayer, moss cleaner (a agent for removing moss), and high-pressure water gun.

How to remove moss:

1. According to the floor/wall area, put an appropriate amount of agent into the barrel of the sprayer. This type of agent is available on the market.

2. After adding the medicine, use a container to collect an appropriate amount of water and add it into it.

3. Spray the prepared chemical solution evenly on the mossy areas.

4. After spraying the agent, use a high-pressure water gun to spray, and the floor/wall will be as clean as ever.