Mold fungus and moist in left corner of window frame and on glas

5 Important Facts About Mold Everyone Needs to Know

Mold can grow on almost any surface, and over 100,000 known species exist. In the wild, mold serves an important function. But indoor mold poses major challenges to health and home, oftentimes requiring mold testing and expert recommendations. To better understand the factors behind mold growth, here are five of the most important mold facts that homeowners and building superintendents should be aware of.

1. Mold Can Grow Virtually Anywhere With Excessive Moisture

Mold spores are everywhere—in fact, each breath contains 1 to 10 spores. They are not always toxic to humans but can become toxic in self-perpetuating colonies within a closed space. This can occur when almost anything with moisture fails to fully dry out, such as towels, pillows, ceiling tiles, carpets, and insulation. Mold can also grow in attics and foundations, where the problem can easily escape notice.

Keep in mind that mold cannot grow on non-porous materials (such as metal) without some kind of dust or film. If you suspect mold, here are several of the most common signs you may need a mold inspection from an experienced professional.

2. Mold Growth Only Takes About 24 to 48 Hours

Mold quickly begins growing in a perpetually wet, dark, and warm environment, so it’s essential to routinely clean and air out moist areas to inhibit mold growth. Be sure to promptly report any signs of mold damage to the building superintendent, who will appreciate your looking out for their interests.

3. Reducing Indoor Humidity Levels Can Help Solve Mold Problems

Areas with poor airflow and ventilation also contribute to mold growth, because airflow speeds up evaporation. Increasing airflow and decreasing humidity (aim for humidity levels between 30% and 50%) will mitigate mold growth dramatically and are crucial to reducing mold that has already taken hold. If the mold is severe, be cautious not to spread spores to other parts of the house.

4. Mold Exposure Can Cause a Host of Health Problems

Since mold prefers dark and damp areas, people are less likely to see it, so the adverse health effects of mold can be easy to misdiagnose. Generally, early symptoms of mold exposure can include:

  • Asthma attacks
  • Runny nose
  • Respiratory issues
  • Itchy eyes or skin
  • Allergic reactions

These symptoms are also common in more innocuous illnesses, such as allergies to pets or dust. Mold symptoms, however, are more likely to exacerbate if nothing is done.

Once discovered, identifying the mold strain(s) is essential, especially if symptoms continually worsen. Identification will help your health practitioner and mold remediation specialist apply more effective treatments. Before it gets to that point, be vigilant for early signs of mold and take proactive actions.

5. Paint Does Not Kill Mold

It might be tempting to try solving the issue with the old “landlord special,” but painting over mold does not stop mold. Instead, you’ll need anti-microbial solvents, such as the product Shockwave from Fiberlock. More severe mold issues will necessitate treatments requiring specialized equipment.


Mold in the home is rarely benign and often quite harmful—but with some knowledge and proactive interventions, you can quickly and effectively protect your physical health and your property’s structural integrity. Don’t hesitate to contact us if you notice mold or its early warning signs. With over 20 years of experience in the greater St. Louis area, St. John Environmental Consulting’s mold testing services help families and building owners restore their property (and their health).

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