Mold on windowsills or in bathroom? EPA and CDC say how to remove it
Learn how to get rid of mold in bathrooms and on windowsills (photo: Styler)
Mold in the bathroom or on a windowsill often develops because of excess moisture. Condensation, cold surfaces, and poor air circulation can also trigger its growth. If you simply remove the dark spots without addressing the underlying cause, the mold may come back.
RBC-Ukraine explains what to do if mold appears in the bathroom or on a windowsill.
Why mold appears
Mold most often develops on surfaces that regularly contact moisture. In the bathroom, these can include grout between tiles, corners, ceilings, and surfaces near the shower or bathtub.
On windowsills, the cause may be different. As temperatures drop, condensation forms more often on glass and window frames—water vapor in the air settles on a cold surface as droplets. If water regularly remains on the surface, it can create conditions for mold to grow.
According to the UK government, inadequate ventilation, cold surfaces, heating problems and poor insulation can contribute to dampness and mold. Leaks can also cause dampness, so not every case should be attributed solely to household humidity.
Where excess moisture in home comes from
Moisture is produced during everyday household activities. People release it when they shower, cook, do laundry, and dry clothes. Even breathing adds water vapor to the air.
If moisture does not escape, it accumulates indoors and settles on cold surfaces. That is why it is important to remove moisture while showering, cooking, and drying clothes.
Turn on the exhaust fan while showering and use a kitchen range hood that vents air outdoors when cooking. A recirculating range hood returns air to the room and does not remove moisture. Do not block ventilation openings or air-inlet vents.
How to get rid of mold in bathroom and on windowsills
- Clean according to the material. You can remove mold from hard surfaces with water and detergent, then dry thoroughly. Porous materials affected by mold may sometimes need to be replaced. These are recommendations from the US Environmental Protection Agency. Wear gloves and protective eyewear, and ensure a supply of fresh air. Do not mix bleach-based products with other household chemicals.
- Ventilate the bathroom after showering. Turn on the exhaust fan during showers. If the air remains humid, check whether the ventilation system is working properly. The UK government's home ventilation guide notes that bathroom ventilation should remove moisture adequately.
- Wipe condensation off the windowsill. This can help remove excess water from surfaces, but it will not eliminate the underlying cause.
- Control humidity. Use a hygrometer to check humidity levels. If humidity remains consistently high, you may need a dehumidifier. The CDC recommends keeping indoor humidity at or below 50%.
- Do not paint over mold. First, remove the mold, address the moisture source, and dry the surface. Paint applied over mold can peel.
When to call a professional
According to EPA recommendations, you can usually clean mold covering less than about 0.9 square meters yourself. If the affected area is larger, there has been significant flooding, or the mold keeps returning, contact a professional. After sewage contamination, professional cleaning is required.
Controlling moisture is an important way to prevent mold from returning. Spending time in damp and moldy environments may be associated with symptoms such as nasal congestion, coughing, wheezing, and irritation of the eyes and skin. People with mold allergies or asthma may experience more severe reactions.
This material is for informational purposes only and should not be used for medical diagnosis or self-treatment. Our goal is to provide readers with accurate information about symptoms, causes, and methods of detecting diseases. RBС-Ukraine is not responsible for any diagnoses that readers may make based on materials from the resource. We do not recommend self-treatment and advise consulting a doctor in case of any health concerns.
