When mold shows up in a home, it can feel overwhelming. However, mold growth usually comes down to a few simple factors. Mold needs three key things to survive: food, water, and oxygen. For this reason, we’ll focus on food and water — the two factors that usually cause problems in homes. Despite the misinformation out there, mold behaves like any other fungus at its core. By understanding these two key factors, you can spot problems early and prevent them from spreading in your home. We’re here to keep it factual and simple.
WHERE MOLD COMES FROM
Mold belongs to the fungi kingdom, just like mushrooms. For example, think about what happens when a tree falls in the forest. The wood begins to decompose, creating organic material that fungi feed on. As a result, you get mycelium, fruiting bodies, and spores. Mold works the same way — feeding on and breaking down organic materials as part of its growth process.
THE “FOOD”
Inside buildings, however, mold often feeds on construction materials that contain organic matter.
- Drywall is a major target. Its paper backing (made of cellulose) is exactly the kind of “food” mold loves.
- Wood — found in trim, doors, baseboards, and crown molding — is another favorite.
When these materials get wet and stay damp, they create the perfect breeding ground for mold colonies to take hold.
WHERE THE WATER COMES FROM
For mold to thrive, moisture is the key ingredient. Common water sources include:
- Roof leaks
- Plumbing leaks
- Flooding
- High indoor humidity
Even small, unnoticed leaks can keep materials damp long enough for mold to start growing behind walls or under floors. These are the basic conditions that allow mold to settle in and spread.
WHY A GOOD INSPECTION MATTERS
A solid mold inspection goes beyond air and surface sampling. A good inspector knows to look for the environment that makes mold possible, the combination of food sources and moisture that allows it to thrive. By identifying and addressing these root causes, you’re not just treating symptoms — you’re preventing the problem from coming back. If you suspect mold in your home, it’s best to schedule a professional mold inspection. Trained inspectors can spot hidden issues, identify moisture sources, and give you a clear plan to keep your home safe and mold-free.
Check out our short video where we walk you through the basics of how mold grows!
Watch the video here!