Common Causes of Mold Growth and How to Prevent It

by | Feb 15, 2025 | Mold Remediation, Mold Removal

Runaway mold growth is an all-too-common problem in modern buildings and one that is frequently invisible. Mold can grow and spread undetected for years, hidden behind walls, underneath floorboards, and even tucked into carpet fibers. As it spreads out of sight, it releases toxic spores into the indoor atmosphere, putting the inhabitants of the building at risk with compromised air quality. It also weakens the building’s structures, eventually necessitating costly repairs if not addressed.

At Biodynamic, we specialize in mold remediation. Our job is to eliminate mold and every sign that an infestation existed. Our thorough cleaning and repair methods can remove every spore from a building. However, it’s also critical to address the causes of mold growth to prevent recurrence. In the following article, we’ll discuss how to identify these causes so that you can prevent mold from taking hold inside your building.

What Is Mold?

The term mold refers to the growth caused by several different types of fungus, all of which spread by releasing microscopic spores into the atmosphere. These spores are carried by the wind, on clothing, in pet fur, and through the ductwork of buildings. When a spore finds an environment that can support its growth—a space that is moist and temperate—it anchors and begins to replicate, spreading the infestation further and exposing residents to dangerous mycotoxins.

Signs of an Infestation

There are many indoor areas with the perfect moisture-rich conditions for hosting a mold infestation, such as in bathrooms and kitchens, underneath sinks, in basements and crawlspaces, along pipes in walls, in ductwork, and in attics. Many of these areas are hidden, making mold more difficult to identify unless you’re looking for it. So, you need to be aware of other possible signs.

Sometimes, mold growth is obvious, appearing as a fuzzy green, grey, or black growth on top of wood, paper, carpet, and other materials. For instance, your carpeting may develop black or green patches as mold inhabits the spaces between the fibers. Brown, black, or green spots or streaks may appear on walls or wooden structural supports.

In other cases, the signs of a mold infestation might not be noticeable. You may only begin to suspect its presence because of its effects. For example, if the residents of a building begin to get sick more often or exhibit signs of respiratory problems, such as frequent coughing and sneezing, then this may be a sign the air has toxic, microscopic mold spores. If you suspect mold is causing health problems for the residents of your building, it’s a good idea to have your space tested by a professional.

Mold Needs Moisture

As we mentioned above, to grow and spread, mold requires a source of moisture. Mold thrives in warm, wet environments, and the more water it can get, the faster it’ll spread. Below are several of the most common sources of uncontrolled moisture in a building, which also makes them common causes of mold growth:

1. Humidity

A great deal of moisture in a building is carried in the air in the form of humidity. Water vapor can provide mold with the moisture it needs to grow.

2. Leaky Roofs or Siding

Water often enters buildings through leaks in the roof or siding, and since that water ends up in the attic or walls, it can be hard to detect until there is a substantial problem. Even minor leaks can lead to mold growth, and often, such leaks go unnoticed until spots of mold begin to appear on ceilings or walls.

3. Plumbing Problems

Mold is also frequently the result of leaky pipes and other plumbing issues. A burst pipe would be an obvious issue, but even a small trickle of water can provide enough of a moisture source for an infestation. And since pipes are typically located within walls and under floors, leaks can go undetected for a long time.

4. Floods and Other Storm Damage

The above causes allow water to enter a building sneakily, often without the residents even being aware of it. However, water also enters buildings as a result of dramatic events, such as flooding or storm damage. Even after extensive cleanup, residual moisture may remain in the walls, floors, or building materials, allowing mold infestations to thrive unless the issue is dealt with.

Preventing Mold Growth

Once mold has been discovered in a building, it must be removed—more on that in the next section. Before that point, however, steps can be taken toward prevention.

The most effective way to prevent mold from growing indoors is to remove its access to moisture. This means addressing the common causes of mold growth listed above by removing excess water from the building. The following best practices will help:

  • Control humidity. An effort should be made to improve ventilation in the building to control humidity. This is especially important in spaces with a lot of moisture, such as bathrooms or laundry rooms, but in general as well. If proper ventilation isn’t possible, consider investing in a dehumidifier if you live in a particularly humid environment.
  • Dry everything quickly. If an area has become wet, it must be dried as quickly as possible—ideally, within 48 hours—or dormant mold spores will begin to activate. Sop up and remove as much water as possible using towels and pumps, and then increase ventilation until the rest of the moisture has been eliminated. Opening windows, setting up fans, and running a dehumidifier can help to dry things more quickly.
  • Invest in maintenance. Regular maintenance should be undertaken on the building’s roof, siding, insulation, and plumbing systems. Any leaks should be addressed immediately before they can encourage an infestation.

What To Do If a Mold Infestation Occurs

If your home has experienced a mold infestation or a major catastrophe such as a flood that you think may lead to one, professional services may be necessary. Restoration companies like Biodynamic can assist with drying out your building and making repairs after water or storm damage. We can also provide mold remediation services if mold has already begun to take hold.

During remediation, your belongings are removed and cleaned to eliminate all traces of mold, and we will help mitigate the original causes of the mold growth so the problem doesn’t recur. With mold remediation, your building can be fully restored to its pre-loss condition, ensuring a return to a clean and healthy environment.

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