Microbial Growth consists of naturally occurring microscopic organisms which are reproduced by spores.  Microbial growth breaks down and feeds on organic matter in the environment.  The microbial growth spores spread through the air and the combination of excessive moisture and organic matter allows for microbial growth.  Not all, but certain types and amounts of microbial growth can lead to adverse health effects and/or allergic reactions.  Not all growths are easily visible, but as the growth persists, it can be seen in the form of discoloration, ranging from white to orange and from green to brown and black, and often there is accompanied by a musty odor present.  Reducing moisture and good housekeeping significantly reduces the chance of microbial growth.  Moisture is a leading contributor to active microbial growth.

Homeowners should use all air conditioning, if provided, in a manner to keep the premises relative humidity within a range of 50% or less.  The magic range is 30-50%.  Homeowners may require the use of a dehumidifying system to aid in humidity control while the home is unoccupied.  Homeowners need to know that relative humidity is dependent on air temperature, too.  If the water vapor content stays the same and the temperature drops, the relative humidity increases.  If the water vapor content stays the same and the temperature rises and the temperature rises, the relative humidity decreases.  Relative humidity depends on temperature and the pressure of the system of interest.  The same amount of water vapor results in higher relative humidity in cool air than warm air.  This is why you should have a properly functioning air conditioning system to assist in climate control and moisture level management.

Imagine that you have a balloon and you inflate it using your breath to a circumference of about 6 inches.  Now, pinch the end closed and hold the pinched end upward and allow the “ballooned” portion to point down (inverted).  You should be able to see a small amount of moisture from your breath gather at the bottom of the balloon.  Liken this to your room at the peak temperature of the day. Now, while still holding the balloon inverted, allow about a 1/4 of the balloon air to slowly release.  The balloon virtually has the same amount of moisture/ humidity as it did when fully expanded.  Thus, you have higher moisture content in the same area and a higher level of humidity.  This is the same thing that happens in your home as things cool down.

The relative humidity is influenced by temperature and geographic location.  Warmer air holds more moisture than cooler air, and warmer weather promotes evaporation.  Areas with a lot of surface water, such as coastal areas like SWFL and areas with high rainfall, have high humidity levels due to evaporation.  Humidity occurs in indoor environments due to building construction related causes.  Porous walls, dampness, and leaks in the structure contribute to structural dampness due to elevated humidity levels.  The construction methods and materials can also lead to humidity and unwanted moisture in the indoor environment.


  • Use your air conditioner
  • Use exhaust, vent  and circulating fans
  • Take cooler showers
  • Fix water leaks
  • Keep your gutters clean
  • Dry your laundry outdoors
  • Use a dehumidifier
  • Reduce the number of house plants
  • Use charcoal briquettes
  • Sometimes just opening a window helps

It is important to know that microbial growths can occur virtually on any surface, as long as three elements are present:

  1. Moisture or water
  2. Oxygen
  3. Organic material sours

Microbial growths cannot spread without these conditions, but, spores may survive in a dormant state until conditions are suitable for growth. Most spores cannot grow with temperatures below 40 F or without moisture or water. Microbial growths can flourish under the right conditions in as few as 72 hours.  The longer a growth is left untreated the higher the remediation cost.  Early detection may keep minor damages from becoming a major disaster.  Professional remediation costs range from a low of $500 to $6000 with the average homeowner spending between $1500 and $3000 if detected early.  Costs can escalate into the tens of thousands if left untreated.

Carefree Home Watch is a professional home watch service provider serving the greater Fort Myers area and offers absentee homeowners assistance in early detection of microbial growths by measure by monitoring conditions and the environment of homes on a regular basis.  Our home watch reporters perform checks to ensure that water sources are secured and off and they use a hygrometer/thermometer device to record relative humidity and temperature levels. We check water faucets, drains and water connections to assist in the early detection of leaks.  They also adjust the air conditioning temperatures to aid in home humidity control based on current conditions and needs.  Call Carefree Home Watch for a free evaluation at 239-234-1847, or, visit www.carefreehomewatch.com for more information.  

Use this link to view the Ultimate Home Watch Interview Guide provided by the International Home Watch Alliance which provides a great deal of information on how to select the right home watch professional to care for your home.