Is There a Difference Between Mould and Mildew?


With water damage claims on the rise, we hear a lot of talk these days about the dangers of mould.  Within 24 to 48 hours of water damage, mildew and mould can start growing on wood products, tiles, drywall, carpets, fabrics and other organic materials.  Even worse, it will continue to grow until steps are taken to eliminate the source of moisture, and effectively deal with the problem. 

So what is the difference between mould and mildew?  Plain and simple, mildew and mould are both fungi. Fungi can live in many different types of environments such as in soil, on vegetation, and on surfaces exposed to moist conditions like a wall or ceiling after flood damage. Fungi reproduce by spores and can spread quickly.

What is mildew? 

Mildew is mould in its early stage and often the term is used interchangeably with the word mould. That whitish-gray, powdery substance sometimes seen on the leaves of a plant is mildew. Mildew is a surface fungi that grows on organic material like plants and food as well as wood, drywall, upholstery, fabric, wallpaper, drapery, ceiling tiles, and carpeting.

How is it different from Mould? 

Mould ranges in color from green to gray, brownish and black. It may appear fuzzy, flat or even slimy. Green slimy mould may develop in the damp, shady areas of decks and even vinyl siding, while indoors, mould can develop on grout, tile and other surfaces found in and around bathrooms and other areas with high humidity and inadequate ventilation.

Dangers of Mildew and Mould

In a battle between mildew vs. mould, which presents more problems and danger? It depends on several factors.

The powdery mildew often found on the leaves of a houseplant, typically poses little danger to you, but it can harm the plant. However, anyone that suffers from mould allergies should avoid touching that mildew. If contact occurs, wash hands thoroughly and never touch your face/eyes/nose after coming in contact with mildew.

According to the Centers for Disease Control and Prevention (CDC) exposure to mould can cause the following reactions:

  • Eye, nose, and throat irritation
  • Cough or congestion
  • Aggravation of asthma
  • Fatigue
  • Headaches
  • Difficulty concentrating

 People suffering from compromised immune systems, chronic upper respiratory illnesses and asthma are at a higher risk for reactions when exposed to mould.

The Need for Mould Removal

Mould and mildew, if ignored, can cause long-term health issues and physical damage to a home or business. While it is interesting be able to identify what type of mould may be growing, it is not necessary to identify the type(s) present. The Centers for Disease Control and Prevention (CDC) states that all moulds (green, gray, brownish or black mould) should be treated the same in terms of health risk and removal. Mould found anywhere indoors, such as behind drywall, on insulation, around windows and along basement walls have developed because there is a moisture problem. To avoid further damage, it's essential to locate and correct the source of the moisture and then remove all traces of mould.

Any home or business that's suffered any type of water damage (from firefighting efforts, roof leak, burst pipe or flood) needs professional assessment quickly. Contact ServiceMaster Restore immediately after any water disaster, as mould can begin developing within 24 to 48 hours. Trust our professional technicians for a comprehensive mould removal plan. Call 1-800-RESPOND.