Mold: Growth, Causes & Ventilation

Mold is a type of fungus that consists of small organisms found almost everywhere. Mold can be black, white, orange, green or purple. When mold is growing on a surface, spores can be released into the air where they can be easily inhaled. These spores in small amounts may not be harmful, however as the spores grow, mold can create rather large health issues.

What Mold Needs to Grow

Mold needs these conditions before it can begin to grow in a home:

  • Moisture ( water leaks, humidity)
  • Food Source (wood, drywall, cotton)
  • Darkness (mold can’t grow under ultraviolet light)
  • Warmth (mold can’t grow in freezing temperatures)
  • Oxygen
  • Time (most molds can begin to grow in 24-48 hours if the conditions are right)

Causes of Moisture & Mold Growth

Moisture is the key cause of mold growth since the other conditions on the above list are always present in a home. Ensuring proper moisture levels are maintained in your home will protect you from mold damage. Maintaining proper moisture levels may require a dehumidifier running in certain areas, or having an attic properly ventilated.


If the weather is humid for a few days in a row, you might notice mold starting to grow in your home. For instance, when it rains for several days, it’s especially common to see mold growth on walls, benches and other surfaces because of the wet air. Mold growth can also be a recurring problem in areas where humidity is naturally high, like on the coast of Tampa FL or other large bodies of water.

The problem with humidity is that there are some molds that only need the humidity level to be higher than 55% to start growing. Not only does high humidity feed mold, but it means that puddles of water and damp materials in the home take longer to dry out. These wet surfaces can, in turn, create mold growth of their own.

Pipe Leaks

Pipes leaking water are a common cause of mold growth. The worst leaks are the ones that go undetected because they are hidden out of view, like inside a wall. By the time you discover these leaks, mold has usually started to grow already.

Roof Leaks

Like some leaking pipes, a roof that leaks into the attic might not be discovered until mold growth has begun. The best thing to do is to check the attic regularly for leaks and keep an eye on the ceiling below the attic. If you notice any signs of water damage on the ceiling or any mold that has grown through, then you probably have a leaky roof.

Poor Ventilation

When moisture inside your house evaporates into the air, it increases the humidity indoors. If your home isn’t well ventilated, then the humidity will remain at elevated levels, creating pockets of stagnant moist air for mold to thrive in. Steam and water evaporating into the air creates humidity that needs to be circulated outdoors through windows to keep the moisture levels balanced. Ventilation is especially important in rooms such as the bathroom and the kitchen where there is a lot of moisture and steam.

Wet Clothes & Fabrics

If you leave clothes wet for a long period of time in your house, mold can grow on them, as well as on other surfaces due to the moisture wet clothes release into your home. Damp clothes left in a pile waiting to be washed for more than a day can lead to mold growth. Clothes left wet for over a day after being washed may start to have a smell, known as mildew. This is the start of fungus growth and may take special treatment to remove from the fabric.

Preventing & Treating Mold Growth

By monitoring humidity and moisture levels, properly ventilating your home, using dehumidifiers, and repairing leaky pipes and roofs, you can help to prevent mold growth in your home. However, once mold takes hold, it’s best to contact a professional for removal and sanitization.

MacFawn Fire & Flood Restoration is a fully licensed mold remediation company with more than 30 years of experience in mold removal. We follow strict health and safety guidelines, and use a multi-step mold removal process, which includes fixing the conditions that are causing the mold to grow, removing all damaged materials, and treating the affected areas with non-toxic antimicrobials to deter mold from returning.

For mold mitigation and remediation in Albany, Saratoga and Glens Falls NY, as well as Worcester MA, Tampa FL and Media PA, call us 24 hours a day at (877) MAC-FAWN.