The Ultimate Detailed Guide On How To Read Mold Test Results

For those asking how to read mold test results, the answer could get a bit complicated. Interpreting and reading the results of mold sampling always had been an arduous task. 

That is why several mold inspectors merely hand off the almost incomprehensible lab results and make a run for it before unsuspecting homeowners could ask their burning questions.

how to read mold test results

Of course, not all mold inspectors are like this, as many would gladly assist you and see everything through the end. However, if you are wondering how to read these reports, it is a good chance that your mold inspector fell on the former description.

To help, here is a helpful and informative guide that can help you interpret and understand your mold test results! 


What Are Mold Tests?

If you research mold, you will probably stumble upon the various services and costs that list mold inspection and testing. These terms may seem synonymous, but they mean entirely different processes.

Mold inspection only identifies the presence of mold and defines the size of the problem, typically in square footage. It is when someone comes to the building or house to look for visible signs of mold growth.

Mold inspection is usually on the pricey side but did you know you can have one for free? To learn more, here is an article on how you can get a free mold inspection.

On the other hand, mold testing attempts to identify the specific mold type found in a home and how many mold spores are present in the air. Most mold testing involves gathering samples of either a surface or the air.

 Essentially, that sample is tested by the mold inspector to find what kind of mold exists and if it can grow in the area. 


How To Properly Read Mold Test Results

The challenges related to interpreting mold test results are frustrating but downright understandable. Mold spores are ubiquitous and pervasive.

Unless the room is airtight and sealed, the chances of the results increasing tenfold an hour after testing are entirely possible.

When you look at mold test results, the first thing that will probably catch your attention is the many columns and numbers. Figuring out what they mean is undoubtedly a challenge.

However, knowing about these data can be helpful in reading and interpreting it later. 

Most spore trap test results include:

  • Columns for the number of spores counted
  • The amount of air samples
  • A calculation of spores/m^3 in the air for each spore type

Spore trap results also include a handful of indoor samples and a minimum of at least one outdoor sample. The outdoor sample is usually necessary to compare with the indoor samples.

Most labs typically use a chart that displays how many of which types of mold are present.

The ‘raw count’ on the results indicates how many spores are on the air cartridge. It is particularly helpful when conceptualizing how many spores are drawn through the air cartridge within the specific area it was taken.

Next is to assess the Count/M3 or Spores/M3 column. This part shows how many mold spores are present in a cubic meter of air through statistical analysis.

The formula most mold testing labs use to calculate the number of mold spores present per cubic meter is as follows:

Raw Count x (1000 / Total Volume in Liters)

If you see several mold species and spore counts present in your home, do not panic immediately! That is entirely normal since no home is completely mold-free.

The last thing you will probably notice is the ‘total’ on the bottom. In most instances, outdoor spore levels should be higher than indoor levels.

It is important to note that mold test results are only an aspect of data you should rely on when dealing with mold. The emphasis on the test in this article is purely informational. 


What Is A Good Mold Test Report?

A good mold test should be clear and complete. It must include all the necessary findings of the mold inspector.

Also, it should provide accurate diagnostic and prescriptive data and information to the client and suggest how to remove the said problem.

A well-written mold test report must include the identification of the mold and an indication of where and how big the problem is. Additionally, a good mold test should identify and recognize the dominant levels of particles that are present in the surface, air, and other samples.

You can check out this article about how to write a mold report to know more! 


What Mold Spores Level Is Considered High?

When you see that you reach 1500-3000 spores, that means that the mold concentration in that area is slightly elevated.

When it gets to the range of 4000-10,000, the spores level is moderate to high. Some remediation is necessary at this point.

10,000-25,000 indicates high levels, and mold spore source is easily visible. Over 25,000 spores mean that a professional mold remediator is needed. 



Learning how to read mold test results would benefit you as it can help you understand the findings, the severity, and possible solution to your mold nightmare. Mold test results could be complicated at first, but knowing the information and data indicated on the report could help you deal with your mold issue.

1 thought on “The Ultimate Detailed Guide On How To Read Mold Test Results”

  1. Thanks for sharing.

    A normal mold spore count in a room is typically 200-500 spores. Anywhere between 1-1500 mold spores in a room is normal and safe as long as mold colonies are not visibly growing and no water damage is present. Mold spores are present in virtually every room of every building.


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