Mold vs Mildew: Which Does Your House Have?

A lot of people mistakenly use the terms mold and mildew interchangeably. It creates an impression that the two terms mean the same. The truth could not be further. Mold and mildew are both fungi developed due to moisture and cause health concerns. As similar as they seem to be, the two are slightly different. In this article, we will explore this difference. 

Mold and Mildew: How do they form?

Mold and Mildew have similar formation paths and times. After a surface has been dampened, it takes about 24 to 48 hours for both the fungi to grow. Three major components contribute to their growth: food (soil), water, and oxygen. 

Decreasing any of them can hinder their growth and vice versa. The difference in growth between mold and mildew remains in how they grow. While mildew remains on the surface and spreads outward, mold eats into the base and may grow upward. 

Causes of mildew and mold

One of the biggest causative agents of mildew and mold is moisture. When mold spores enter your house, poor ventilation, lack of sunlight, excessive moisture, and dirt and debris can lead to fungal growth in your house. Some of the places vulnerable to mold and mildew growth include, 

  • HVAC vents
  • Under carpeting
  • Crawl spaces
  • Bathtubs and showers

Differences between mold and mildew

Despite having similar growth patterns and causes, mold and mildew have significant differences. For one, mold grows higher and becomes fuzzy. On the contrary, mildew always remains flat. Moreover, mildew starts off as white and turns gray and brown over time. 

Mold, however, takes darker shades like deep green and black. Lastly, mold remains as it is and grows further and deeper, making it hard to remove, while mildew converts into a white powdery substance.

Visual differences between mold and mildew: 

Mold Mildew
1. Green, black, or red 1. White/gray in early stages, and turns brown
2. Mistaken for dirt 2. Looks like a small dot
3. Tends to grow higher or deeper 3. Remains flat
4. Becomes fuzzy over time 4. Becomes powdery


How to prevent mold and mildew

The best way to prevent mold and mildew growth in your house is by ensuring there is enough ventilation (natural and manmade) in the rooms. Moreover, make sure to install dehumidifiers in rooms with more humidity and moisture. 


Mold and mildew are both likely to be found in a range of places in the house and under different temperatures. Both of these can cause serious damage to the house and health concerns in the residents. Therefore, mold and mildew are often looked out for during a home inspection in Hudson Valley NY, to prevent any harm to the potential buyers. Make sure you look out for these too!

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