Black, green, white spots on the walls, ceiling, in the corners of the bathroom. Mold is not just an aesthetic defect. It is a poison that slowly poisons the lives of the residents. Mold spores float in the air, settle in the lungs, cause allergies, asthma, chronic bronchitis. Black mold (Aspergillus niger) is especially dangerous. It releases mycotoxins that can affect the nervous system. In 2026, the problem of mold in apartments became more acute due to the widespread installation of plastic windows (no ventilation) and a love for drying laundry in rooms. We discuss the causes of mold and methods of fighting it.

Causes of mold appearance

Mold loves three things: warmth, humidity, and lack of air movement. Where does the humidity come from? Poor ventilation (clogged grilles, non-working exhausts). Drying laundry indoors (10 kg of wet laundry releases 5 liters of water into the air). Leaking pipes, roof, wall freezing. Aquariums, flowers, frequent boiling of the kettle. Incorrect installation of plastic windows (no microventilation). Without eliminating the cause, fighting mold is useless.

Prevention: how to prevent mold

Regularly ventilate (2-3 times a day for 10-15 minutes), even in winter. Install intake valves on windows (a cheap solution) or bризеры. Check the operation of ventilation: bring a piece of paper to the grille — if it sticks, everything is fine. Do not dry laundry in the room (use a dryer or balcony). Move furniture away from the walls by 5-7 cm for air circulation. Install an exhaust hood over the stove. After taking a shower, wipe the tiles dry. The humidity level in the room should be 40-60% (buy a hygrometer).

How to fight mold with folk remedies

If mold has just appeared (a small spot), try: vinegar solution (9% table vinegar) — apply, leave for an hour, rinse. Hydrogen peroxide (3%) — spray, leave for 10 minutes, wipe. Ammonia (diluted 1:1 with water) — effective, but toxic (work in a mask). Baking soda (paste of baking soda and water) — soft, safe, not very effective for deep mold. Copper sulfate (20 g per liter of water) — a strong remedy, but toxic, leaves blue stains. Folk methods are suitable only for smooth surfaces (tile, glass), they do not work on wallpaper.

Store antiseptics and fungicides

For serious contamination, use special agents: "Fungifluid" (Alpa), "Mellerud", "Plezonel", "Deo-anti-mold". They contain chlorine, quaternary ammonium compounds, or copper sulfate. Apply with a brush or sprayer, leave for 10-30 minutes, then rinse. Always wear a respirator, gloves, protective glasses when working. Ventilate the room. Some agents do not rinse and form a film preventing re-growth. Read the instructions before purchasing: for which surfaces (wallpaper, concrete, paint).

Removing mold from different surfaces

Wallpaper: if mold has penetrated under the wallpaper, it will have to be removed (fungicide will not pass through the layer of glue). After removing the wallpaper, treat the wall with an antiseptic. Paint: if mold is on oil paint, wipe with a damp rag with soap, then treat with vinegar or antiseptic. Tile and grout: treat the joints with bleach (chlorine), leave overnight. Then scrub with an old toothbrush. Concrete and plaster: deep penetration. You need to scrape off the contaminated layer with a spatula, heat with a construction hairdryer (to destroy spores), then impregnate with fungicide in 2-3 layers.

Mold on ventilation and air conditioning

Black film on the ventilation grille is a breeding ground for spores. Remove the grille, wash it with chlorine. Cleaning the shaft is difficult (call specialists with chemical treatment). In the air conditioner, mold lives on the filters and in the drainage system. Wash the filters once a month in a vinegar solution (1:1) or call cleaning.

What to do if mold returns

This means that the cause has not been eliminated. It may be that the walls are freezing (insulate them with extruded polystyrene from the inside, but this is a risk — the dew point will shift). Or the basement under you is damp (you need hydroisolation). Or neighbors above are flooding (file a complaint with the housing department). In multi-story buildings, forced ventilation is sometimes required (install a fan in the exhaust). If you are a tenant, demand repairs from the owner.

Dangers of DIY methods with bleach

Chlorine (bleach) effectively kills mold on smooth surfaces, but on porous (wood, gypsum board, plaster) chlorine does not penetrate deep into the surface and kills only the superficial layer. The water in which chlorine is diluted is absorbed and creates a favorable environment for new mold. Do not use chlorine on wood and untreated concrete. It is better to use special "dry" agents (borax, borax).

Fighting mold is a marathon, not a sprint. Start with eliminating humidity. Then remove visible mold. Treat with fungicide. And constantly maintain a ventilation regimen. If mold occupies more than 1 square meter and causes allergies in family members — call professionals (disinfection services).

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