The Case for Fogging: Part 2

Cesar Collado
June 1, 2020

Reading Time: 6 minutes

Safety, Economics, and “The Big Picture” 

By Cesar Collado

Last week, I described the science behind fogging in “The Case for Hot or Dry Fogging: Part 1.”  Part 2 will describe how fogging for mold can increase safety and provide economic cost savings when professional help is needed to remediate your home for health concerns.  

While mold is ubiquitous, the source of moisture and mold problem in your home usually leaves some obvious visual evidence.  A water intrusion event, strong odors from an unknown source, and stains or discoloration of walls, ceilings, and carpets are common.  In these cases, identifying the source and having it remediated can be straight forward.  Unfortunately, a severe mold issue coupled by unexplained health symptoms is much more significant and may be dependent on some detective work, either by you or a professional.  To do this, one needs to educate themselves with “The Big Picture” to understand what is at stake.  

For the purpose of this article, I believe unexplained and debilitating health issues would be the key indicators of a potential indoor air quality problem.  In some cases, a physician will suggest having your home tested or inspected to determine if mold inhalation is an issue.  Respiratory symptoms and chronic rhinosinusitis can support the idea of a pathogen that is making you sick.  Other symptoms such as brain fog, memory issues, cognitive and motor dysfunction, and chronic fatigue can be debilitating and have a significant impact on quality of life, relationships, work abilities, and financial stress on any family.  When these symptoms cannot be diagnosed and treated by a physician, the possibility of a mold issue becomes more likely.  The challenge of identifying the source and remediating can be  cumbersome and expensive. 

“The Big Picture”

Because of the microscopic nature, high reproduction rate, and relative ease with which mold spore spread is nearly impossible to control, efforts to identify and fix the source while containing the problem require a thorough strategy or plan.  In the absence of a clear strategy, mold problems can be exacerbated, and occupant health can be further compromised.  DIY efforts without safety considerations can prove extremely costly.  On the other hand, hiring an inspector and professional remediator can incur significant costs.  Given the variance in training and experience with mold professionals, there are wide ranges of cost estimates.   

  • An inspection can cost anywhere from $500-$1000 with testing.
  • Remediation of a predetermined area caused by water intrusion can range from $500-$10,000.
  • A systemic moisture problem and contamination can cost in the tens of thousands of dollars.(I have seen up to $100,000) 
  • HVAC Cleanings range from $300-$600
  • Duct cleaning and sanitation can range from $300-$800, depending on the size of the home andHVAC  


The Case for DIY Testing and Fogging 

There are many practical and economic reasons that make DIY testing and fogging almost essential for remediation to be successful and affordable, even  when professionals are involved.  This is because you are not just decreasing labor costs; but you are narrowing the scope of work to be done by professionals and mitigating the risk of experiencing “Scope Creep” or unnecessary remodeling for which you will ultimately pay.  If the remediation job is not successful, it is “all for naught” in in the event debilitating symptoms continue. 

fogging for mold

Source: EPA

More important, DIY testing and fogging will accelerate healing by a significant reduction of mold spores in the air so that your body can begin to heal by breathing better indoor air quality (“IAQ”). 


Step 1: DIY Visual Inspection

fogging for mold in your home

Inspecting your home does not take a great deal of expertise or effort.  All it requires is a flashlight and time to identify moisture and mold.  Moisture meters, hygrometers, and a phone camera will make the effort more comprehensive. Read more about DIY Home Inspection” HERE. 


Step 2: DIY Testing 

There are many schools of thought regarding the testing of air for mold. It is important to recognize that each of these methodologies have liabilities.  Spore traps and tapes do not represent the home in a statistical fashion.  ERMI tests using vacuumed or wiped up dust provides a scoring that was never intended for health diagnostic purposes and provides limited information.  Several tests can become very costly.  testing for mold in your homePetri dishes have been used for over 70 years and provide conclusive evidence of mold at a minimal price (best bang for the buck).  The key to testing a home sufficiently is to do enough testing of ambient air and suspected mold using plates and swabs to provide information to identify the sources of mold.  Gravity plates in high traffic rooms will provide conclusive evidence that mold does or does not exist in the room.  Swabs can test dust and mold that lie in specific problem areas such as suspected visible mold, HVAC registers and filters, below carpet, behind baseboards, behind wallpaper, and around plumbing  

By triage testing for mold yourself, you can get closer to identifying the moldy areas that are the source(s) of the problem.  The more clearly you can identify the location of potential moisture problems to communicate to the mold professionals, The more cost-effective solutions by the inspector can be explored. With water damaged homes, the identification of mycotoxin producing molds can be the first clue to a potential cause of unexplained health symptoms that someone may be experiencing.  Read more about “DIY Mold Testing With Purpose” HERE. 


Step 3: DIY fogging 

By hot fogging the home, you are able to reach every surface area in each room. Furthermore, the fog will enter nooks and crevices in and around home furnishings.  This will accomplish two very specific and important goals to getting well.    

  1. It will reduce mold spore levels in the air drastically so that you can begin to feel better. 
  2. It will effectively reduce or eliminate wandering moldthat might be mistaken for problem areas to be professionally  

Continued testing using visual plates will ultimately test positive in the areas where there are moisture problems and mold sources.  This information will make the job for inspectors and remediators much more focused.  This can often mean the difference in a focused job in the single digit thousands to identify and fix the moisture issues and remediate moldy materials in a proper manner with all safety and regulatory considerations. 

Given the limited knowledge the average person has on mold testing and remediation, this approach avoids giving “Carte Blanche” to remediation estimators to identify any mold evidence as a problem area potentially needing demolition, remediation, and remodeling.  As mentioned before, this can cost in the tens of thousands of dollars.  Read more about finding qualified mold professionals HERE.  It is important to note that many of the building science professionals (This that I know personally ) that remediate mold are empathetic to the financial strain and the many patient hardships and actually would prefer more precision in order to help keep their services affordable.  Having a “cleaner” canvas can reduce unnecessary labor and testing.

Other Considerations: 


Unfinished Spaces 

In many moldy home situations, the problem can often lie in the areas of the home that are not properly air conditioned.  This specifically means the crawlspace, unfinished basements, and attics.  All of these areas are easy to test and fog; however, identifying a moisture or water accumulation is essential.  Stagnant water can become infested with bacteria, mold, yeast, and attract insects.  If you find stagnant water, you may need to employ a landscaper to install proper drainage to steer water away from the home.  

First, to explain why moisture and mold problems in these spaces are problematic, we must understand some the physics involved in home construction. Each home experiences ventilation effects that determine how indoor and outdoor air moves throughout the house.  There are 3 specific types of ventilation effects normally found in all homes. 

mold and your home

To explain simply, hot air rises and cold air falls.  Most homes are not perfectly sealed so there is air movement between rooms and floors.  When a basement, crawlspace, or attic have moisture and mold issues, the mold spores can travel with the air movement between floors, contaminating the ventilated spaces.  There is also positive and negative air pressure events that can be created by small amounts of airflow with significant impact on the spreading of microscopic particles. 

 Fogging a basement, crawlspace, or attic is fairly straightforward as these areas are primarily reached with a single fogging application.  One fascinating positive impact of fogging these areas is the ability to inspect areas where fog is escaping for leaks.  You can then proactively address these before they become problematic.  

biobalance mold products

Click to Watch Video


HVAC Issues 

In some cases, the HVAC system can be contaminated.  Specific swab testing and a DIY visual inspection of ductwork will tell you whether there is widespread contamination in the ductwork.  If there is, it may need to be replaced.  In most cases, a proper HVAC and Ductwork cleaning can be done by HVAC or remediation professionals.   

 When fogging your home, you can also fog your HVAC system.  Simply remove air filters and turn on the HVAC system fan so that the fog circulates inside your ductwork and HVAC system.  Read more about “HVAC Fogging, Cleaning, and Maintenance” HERE. 

I would like to thank Danny Gough, an environmental professional focused on fixing homes and buildings for people who suffer from environmental illness, for sharing his experience and expertise for writing the past two articles..  

If you would like to share your story or have questions, please comment on this article.