Meaningful Mold Investigations

Far too often I receive calls from homeowners requesting that I make some sense out of another mold consultant’s report.  Usually the report consists of results for a few indoor spore trap air samples and one outdoor comparison sample.  The report might include some general information about the types of mold that were found and how the indoors compared to outdoors.  My general response to these inconclusive reports might be, “The report shows that you have mold in the air, but nowhere in the report are you given advice on removing it.” Of course, the bewildered homeowner is already thinking the same thing, so I try not to rub salt into the wound.

In defense of the consultants, who are frequently home inspectors that rent air sampling pumps, they did what the homeowner requested, which was “test the air.”  They tested the air but did not know what to do with the results.  This is one reason that I strongly object to consultants working outside of their areas of expertise.  A qualified mold investigator would have first asked why a homeowner wanted the air tested for mold.  When I ask this question, the response is usually something along the lines of “I just want to know if I have a mold problem” or “I see mold and want to know if it is the dangerous kind.”


With these responses, a qualified mold investigator would advise the homeowner that taking a few air samples in the home probably would not answer their questions and would likely be an unnecessary expense.

This is because ninety-nine percent of the time, a qualified mold investigator can determine if a mold problem exists by performing a detailed visual evaluation that would include moisture mapping, inspection of common problematic areas, and collecting information on the history of water damage and prior repairs.

Not only will the qualified mold investigator assess the moldiness of the home, he or she will provide a scope (i.e. prescription for remediation of the mold) and correcting the underlying cause.

Although mold sampling is not necessary to assess and remediate mold, under certain circumstances (litigation, doctor request), sampling is advisable.  However, sampling should only be performed to answer a specific question (scientifically, this means to test a hypothesis).  Of course, the hypothesis can only be developed after a detailed mold inspection is completed.

I could provide numerous examples of how simply “sucking air” could not only be useless, but misleading.  However, understanding what to request when vetting a mold consultant.  Foremost, the consultant should describe a detailed visual assessment.  Homeowners should clearly identify why they want mold information prior to calling a consultant.  Information they should be prepared to provide includes: (1) do you see or smell mold; (2) is anyone experiencing symptoms that might be related to mold exposure; (3) is your doctor requesting the information, (4) have you had water damage in the home; (5) how old is the home, (6) how long have you lived there; and (7) do you anticipate litigation.  In some circumstances, no testing will be required.  For others, such as litigation or physician requests, a well-designed sampling plan could be essential.

The Shortcomings of Shortcutting A Mold Remediation Project

My mom’s words of wisdom, “Any job worth doing is worth doing right,” never rang truer than in situations where partial remediation is viewed as being better than no remediation.  Contrary to this misconception, no remediation is better than substandard remediation.  Case in point – a family inherits a home that has been unoccupied for an extended period, and had not maintained for more than ten years.  Water intrusion into the basement and attic caused mold growth to building materials that were in contact with water.  Sustained high humidity resulted in secondary mold growth due to condensation on interior drywall.  Testing revealed concentrations of Penicillium and Aspergillus in the range of 80,000 to 100,000 counts per cubic meter of air.  Outdoor concentrations of spores in these genera were less than 1,000 c/m3.  Toxigenic mold species, such as Stachybotrys chartarum, were also identified.


Contaminated drywall must be removed under controlled conditions.


In the throes of financial difficulties versus living rent-free, the family made a decision to move into the contaminated home and perform remediation in a piecemeal fashion.  They believed that small efforts to remove mold would cumulatively achieve the desired end product of good indoor air quality.  However good their intentions might have been, the reasoning was flawed.

 Unlike cosmetic or structural renovation projects, mold remediation cannot safely be performed “a little bit at a time”.  Effective remediation requires removal of mold contamination along with addressing spores that are liberated from areas of actual mold growth.

Attempting to live in a contaminated home while performing remediation one step at a time is similar to paying minimum monthly payments on a high-interest rate credit card.  There is no light at the end of the tunnel, and the problem compounds over time.  If one area is effectively remediated, yet contamination remains in other locations, re-contamination to the cleaned area will occur.  Additionally, with ongoing exposures, individuals become sensitized and progressively react to lower concentrations of mold.


Mold Test Kits: Why You Should Not Do-It-Yourself

Using a “do-it-yourself” (DIY) mold test kit to evaluate whether a home has a mold problem makes about as much sense as replacing an annual doctor exam with using a thermometer to take your temperature.  Just as a person could be very ill while maintaining a normal temperature, a home could have a serious mold problem, even though a DIY test was negative.

Designing, executing, and understanding a comprehensive indoor mold assessment is difficult enough for professional mold consultants.  The best ones understand that building dynamics, hidden mold, historical damage, sampling techniques, analytical methods, and many other factors can influence the accuracy and effectiveness of diagnosing indoor mold problems. With numerous facets of mold remediation to consider, it becomes more evident that mold remediation simply isn’t a DIY job. Reducing mold remediation down to a DIY testing kit fails to address all of the issues at hand, issues that most professionals are trained to identify.

Sanit-Air’s team is knowledgeable in building science, sampling techniques, and scientific methods. The detailed onsite investigation, which requires knowledge of building science and codes, is the single most important tool in an investigator’s toolbox. Additionally, methodical testing practices are crucial. By utilizing testing methods designed to answer specific questions, Sanit-Air avoids aimless testing that does not yield any helpful information for the remediation process.






Apartment HVAC Closets Can Be A Source of Mold and Degraded IAQ

A common practice in multi-story apartment and condominium complexes is to house the furnaces in closets located on the patio or balcony for each unit. These closets are aligned vertically in each building, which makes it convenient for plumbing access. However, numerous water damage issues are inherent to this type of HVAC set-up.

Water damage from clogged condensate drain tubes or malfunctioning condensate drain pans is common. Slimy biological growth in PVC tubing and drain pans causes overflows. Current or historical overflows from the pans will appear on the sheet metal plenum under the A-coil. Drips and mold growth from malfunctioning units above a closet are commonly apparent as drip stains or growth on the ceiling and walls of the closet.

Ceiling of furnace closet showing water entered from HVAC closet above.

In apartment HVAC systems, water damage caused by freezing and thawing of the AC coils is common. When filter changes are left in the hands of uninformed tenants, plugged filters prevent sufficient airflow to the coil, causing it to freeze. As the coil warms up, the ice thaws, which releases large amounts of water into the return plenum, floor system of the apartment, furnace platform, or furnace closet below the damaged unit.


Another issue associated with stacked HVAC closets is the installation of the furnace on a platform, which is commonly constructed from plywood, drywall, or oriented strand board. When wet, all of these materials support the growth of mold and bacteria, which can produce various toxins. Additionally, the glues and resins in these materials can be liberated when wet, causing additional problems.

Furnace on water damaged OSB platform. The return plenum is located under the platform

When damage does occur, the underlying cause of water must be corrected. This involves replacing clogged drain tubing, cleaning drip pans, cleaning coils, and changing filters. For consistency, preventive measures in the form of routine inspections and HVAC maintenance should be the responsibility of the management company or maintenance staff.

Addressing the consequences of water damage, whether it manifests as biological growth or deteriorated building materials, is imperative to appropriate HVAC hygiene and good indoor air quality. 

Contaminants on water damaged plywood, OSB, and drywall in the furnace closet and on the furnace platform can cause adverse health effects, whether the growth is active or historical. Once dried, mold and bacteria engage in survival mechanisms that can include toxin production and increased sporulation. When dry, the contaminants are easily liberated into the airstream.  Mold remediation is required when building materials in furnace closets become contaminated. The remediation involves two components (1) removal of the mold or contaminated building material and (2) addressing spores that are released from areas of actual growth. Engineering controls, containment barriers, HEPA filtered air filtration devices, personal protective equipment, HEPA vacuuming, and damp-wiping are all essential for safe and effective remediation in water damaged furnace closets.

What You Should Know Before Having Your Home Tested

Mold testing is a complicated process, and therefore should only be performed by well-trained and experienced investigators with a degree in biology, environmental science, or related fields.

As the indoor environment is dynamic, it requires a well-designed sampling plan based on the history of the home, occupant symptoms, and a detailed visual inspection. Any investigator should be able to explain why each sample is necessary and what information will be obtained.

A good sampling plan will generally include several types of testing, including a combination of air samples, surface samples, or dust samples. Samples should be evaluated by an independent third-party laboratory with a certification in indoor environmental microbiology.

Evaluation of sampling data requires specialized expertise with an understanding of peer-reviewed publications. An investigator should have their own sampling database relative to specific geographic areas and different types of indoor contamination.

Sanit-Air has inspected and tested more than 10,000 residential buildings in various regions of the United States and has a database of over 50,000 samples. Through their experience and expertise, Sanit-Air’s employees are uniquely qualified to test and evaluate a home.



Why Sanit-Air?

Welcome to Sanit-Air’s blog! We are excited to start blogging more frequently in order to share our knowledge and to show why we are so passionate about what we do.

Tom and Connie Morbach founded Sanit-Air in 1994 as a duct cleaning company, and they have only grown from there. Tom and Connie’s expertise led them to expand their company into an Indoor Air Quality company. With over 20 years of experience within the Indoor Air Quality and Mold remediation industry, Tom and Connie have refined their techniques in order to provide superior results.

Sanit-Air is different in the Indoor Air Quality and Mold remediation industry. We emphasize a scientific approach to mold remediation and are determined that everything that we do is with reason. Many other companies will perform a few tests that will only provide vague results, and then move on to remediation, and in the process, they may not even address the main issue at hand. Sanit-Air’s scientific approach is unique because we design tests to yield results and get to the bottom of the issue.

Throughout this blog, we intend to share knowledge and give you a “Behind the scenes” look at our company. Too many people simply do not have access to factually correct information without bias. We hope that through sharing our knowledge of scientifically proven methods and facts that we are able to show you why we are passionate about science-based remediation practices.

Our website also has more information- please visit us at We hope that we can begin to answer any questions you may have and to share our knowledge.

Thanks for reading!