High Humidity Causes Mold Growth!


High indoor humidity levels can lead to costly and unsightly mold contamination problems and can lead to serious health problems. Mold requires moisture and organic material to grow and where we have high humidity levels mold will proliferate. We live in a country where our wet winters in the Cape Province causes very high humidity levels resulting in massive amounts of condensation on the inside of buildings. Our hot rainy summers  in coastal areas cause fast evaporation of moisture and very high humidity levels in buildings as well as outdoor.

Our buildings are constructed with low vapor and air barriers, this allow high levels of outside conditions to permeate to the inside of the buildings. We have brick walls that virtually never dries due to our construction mistakes we make. This adds to the high levels of humidity inside of our homes.

Given our security conditions in South Africa, we close windows and doors and our buildings does not ventilate naturally.

We further do not install air bricks, or we close them up, this prevents natural cross ventilation and humidity is trapped inside our homes.

We also install our appliances inside our kitchens that is not vented to the outside, these give off vast amount of humidity. We like long showers and hot steamy baths and we do not put extractor fans in our bathrooms, resulting in high humidity.


The key to mold growth is moisture. Mold can grow on a food source in 24 to 48 hours if the material remains wet. So the best way to prevent mold is by keeping your home dry.


How do I know we have high humidity levels in a building?

In winter you will find condensation forming on the windows.

You will find that your clothing, bed sheeting and curtains feels damp to the touch.

You start seeing mildew, a type of white fluffy mold, growing on clothing and in drawers.

We will also detect a earthy smell on clothing and on entering a building that has been closed up for a couple of days you will smell the mold caused by high humidity.

Another sign of high humidity is your washing does not want to dry.

Curtains hanging against windows suck up condensation from the windows and grows mold.


How do I reduce High Humidity Levels?

The key to reducing mold is good moisture control. Household humidity levels should be maintained between 30% and 50%. Mold thrives in humidity levels higher than 55%.

Buying a hygrometer and measuring the humidity is a start in managing the humidity in your building.

2ndly, maintaining low humidity naturally in coastal areas is almost impossible. Most people try to install air bricks to lower humidity inside the building. The problem lies in the high humidity outside the building flows inside the building resulting in high humidity inside and outside the building.

Install de-humidifiers, it is an essential piece of equipment in coastal areas.

The best humidity and mold removal solution

zambeziThe best way of dealing with high humidity inside a building is removing it with a De-humidifier. Most of the new De-humidifiers use very little electricity and switch off when the targeted humidity is reached. De-humidifiers can be installed against the walls and an outlet pipe can pipe the water captured from dehumidification to the outside of the building. De-humidifiers also assist in speeding up the drying time of drying washing indoors.

Our top of the range Zambezi De-humidifier includes features that can kill mold up to 10m from where you place the de-humidifier. Always remember the air has also been polluted and the mold polluted air makes you ill. The  Zambezi De-humidifier not only removes the humidity but is an excellent mold killer.

Contact us today to do a professional mold assessment or mold clean up.