Mold Growth After Water Damage: What You Need to Know

Jan 5, 2023 | Mold Remediation, Water Damage

Mold Caused by Water Damage


Water entering your home from a storm, plumbing leak, or roof leak can lead to mold growth over an extended period, even if the area affected by the water seems to be dry.

This is because water damage creates an ideal environment for mold to thrive, due to the combination of moisture and organic materials.

Mold can begin growing quickly. If an area remains damp for more than 24 to 48 hours, it is almost certain that mold will start growing, although it may take several weeks for the growth to become noticeable.

Additionally, moisture can often be present in hidden areas such as behind walls and wallpapers, under flooring and carpets, and insulation.

It is important to address moisture promptly to prevent mold growth, as mold can cause health problems and structural damage to the building.

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Common types of molds caused by water damage

All types of molds can potentially grow as a result of water damage. However, the most common types of molds inside buildings with water damage are:

Stachybotrys chartarum

Generally referred to as “black mold”, this feared mold has a greenish-black appearance and commonly grows on cellulose or plant-based materials that have gotten wet. Black mold thrives in hot, humid conditions, particularly after flooding has occurred.

It is often found on surfaces such as wood and wallpaper, and it can grow inside walls with leaky indoor plumbing hidden or other materials that have been continuously wet for an extended period of time.

It can produce toxins that can cause health problems, including respiratory issues and skin irritation. Therefore, those who are sensitive to allergens or have compromised immune systems may experience severe allergic reactions when exposed to black mold and should avoid being in infested rooms.


Cladosporium is allergenic and spreads quickly within the home. It appears olive-green to brown or black in color.

It can grow on damp surfaces like wood, carpets, upholstery, drywall, behind wallpaper, and under floors; and it’s commonly found in areas such as basements, attics, bathrooms, under sinks, and around faucets.


Aspergillus is a common mold, typically black in color, but it can be found in other colors such as green and brown.

It can grow in warm, damp environments on a variety of surfaces, such as paper, insulation, and wallpaper.

Most people breathe in the spores daily without getting sick. However, people with weakened immune systems or lung diseases may develop aspergillosis, an infection caused by Aspergillus.

Preventing issues

In addition to promptly addressing water damage and thoroughly drying the affected area, there are several steps you can take to prevent mold growth:

  • Regularly inspect your home for potential sources of water damage, such as leaky pipes or roof damage.
  • Fix any leaks or plumbing issues promptly.
  • Keep gutters and downspouts clean to prevent water from accumulating on the roof or near the foundation of your building.
  • Keep the humidity levels in your home low.
  • Properly ventilate areas such as bathrooms and kitchens to prevent excess moisture buildup, by using exhaust fans or opening your windows
  • Consider installing a dehumidifier in damp areas of your home.

It is important to note that the presence of mold does not necessarily mean that it is the result of water damage. Mold can also grow due to high humidity levels, or other sources of moisture.

If you are concerned about mold and/or water damage in your home, a professional can help you solve the problems effectively.

The Phoenix Restoration experts can help you. Contact us and we’ll be glad to assist you!