Why Does Mold Grow in My House?

Mold is all around you.

Water Damage

The spores are ubiquitous, in all regions, climates and environments but them to germinate and grow, certain environmental conditions must exist. If you have a problem with mold growing inside your house, you can safely assume that your home environment meets one or more of these conditions.

Mold germinates in moist locations, so if you have standing moisture in your home, you have a very high risk of developing mold colonies. Standing moisture may result from flooding after a rainstorm, water accumulation beneath a leaky pipe, collected rain water dripping in from a poorly-shingled roof or something as simple as a dripping shower head. If you have mold isolated to one area of your home, try to find the source of the moisture and repair it at once.


Lingering moisture does not require rain or poor plumbing. It can also exist in a house due to high relative humidity. When humidity levels rise, the amount of vapor increases in the air and household surfaces become damp, providing the necessary food for mold growth.

If you have a problem with humidity inside the home, invest in a portable dehumidifier to dry out the interior when necessary. Install a hygrometer (relative humidity sensor) in your home to measure the humidity levels at all times. Ideally, you want to keep your relative humidity between 30 and 50 percent.

Excess Dirt

If you have not cleaned or dusted your home in a while, you may greatly increase your chances of developing mold. Excess soil creates the perfect environment for mold, according to a University of Missouri Extension report. Mold spores travel through dirt particles and the combination of dirt and moisture create the precise conditions necessary for growth. Maintain a clean home not only for aesthetic reasons but also to prevent the growth of mold.

Air Circulation

Poor air circulation promotes mold growth through a combination of all the factors mentioned above. Proper air flow draws moisture outdoors, helps to keep indoor humidity at safer levels and inhibits the germination of spores by disallowing standing moisture to bond with dust particles.

On the other hand, if your home lacks proper air flow, mold has the perfect breeding ground. To promote air flow, you need only open windows to allow a natural breeze. Use fans to increase air flow or use your air conditioner in the summer.