Black mould on walls: the Japanese technique for removal and prevention

Dark stains on interior surfaces undermine residents’ wellbeing and damage the building’s structure. The recurring appearance of black mould signals a build-up of excessive moisture, requiring effective cleaning methods and constant ventilation to restore the home environment.

Why does black mould frequently appear on internal walls?

Moisture accumulating in enclosed rooms encourages the rapid growth of micro-organisms that are harmful to human health. Areas with limited air circulation become an ideal habitat for visible fungus to spread, affecting delicate finishes such as paint and plaster.

Placing heavy furniture close to walls prevents air from moving freely, creating cold spots and condensation. Without suitable action, these dark marks quickly spread, reducing indoor air quality and causing persistent unpleasant odours throughout the home.

Is there a chlorine-free home solution for removing mould?

An effective homemade mixture can remove deep stains without chlorine’s harshness, protecting the finish and ensuring… Read more

How does the Japanese technique remove mould effectively?

The method developed in Japan focuses on the careful use of specific products that break down mould without harming the surface. On traditional finishes such as diatomaceous earth, lime walls or sand-based walls, removal is achieved through the product’s chemical action, without mechanical scrubbing.

Applying successive layers makes it possible to remove the dark pigmentation gradually and safely during the process. Ensuring that the product reaches the material’s recesses without soaking the wall prevents permanent damage to earth structures or sand finishes.

Below, watch the YouTube video from the channel カビ取り防カビ対策専門業者の純閃堂【JUNSENDO】, which demonstrates the practical mould-removal process:

What steps ensure drying and protection against mould?

Once the surface has been cleaned, thorough drying is essential to stop fungal activity. Using fans speeds up the evaporation of residual moisture, preparing the wall for a protective layer against the return of mould stains.

Applying an anti-mould agent forms a preventive chemical barrier in areas prone to water-vapour build-up. This added protection neutralises remaining spores and helps the wall stay clean for longer, safeguarding health and the environment.

Anti-mould protection steps

Procedure for preventing mould

The essential stages of the method used to protect surfaces in your home are:

1. Apply a suitable solution without scrubbing delicate materials.
2. Force drying through continuous air circulation in the room.
3. Treat the area with anti-mould spray to create a protective barrier.

How can mould stains be prevented from returning at home?

Maintaining daily ventilation habits in bedrooms and living rooms is crucial for lowering indoor humidity levels. Opening windows regularly and moving large items of furniture away from masonry walls prevents the formation of microclimates that encourage fungi and mould stains.

Regularly checking critical areas, such as wall corners and behind cupboards, helps identify moisture at an early stage. Adopting simple environmental control measures prevents more complex work in the future, preserving the appearance of rooms and the durability of walls.

See the main recommendations below for keeping your home free from excessive moisture:

• Leave a gap of at least five centimetres between furniture and walls;
• Keep windows open during the periods with the most sunlight;
• Use dehumidifiers or air circulators in poorly ventilated rooms.

Why does ongoing care improve the condition of rooms?

Continued attention to ventilation conditions and wall integrity prevents the unnoticed accumulation of harmful spores. Carrying out regular inspections in the most vulnerable areas helps ensure a healthy home free from growths that affect health and finishes.

Combining appropriate cleaning techniques with active prevention delivers lasting results against dark stains. By addressing the root cause through drying and air circulation, the home remains protected, retains its value and stays free from mould on its walls.