How To Test For Black Mold

Testing for black mold or for any other type of mold is an essential part in both preventing the spread of dangerous mold, as well as of combating it.

Testing for mold has a lot of different components – there is the testing for symptoms and there is the actual testing of the air and surfaces. It can be done professionally or it can be done with the help of different mold testing kits.

At first, all this may seem like too much work – after all, if there’s mold, there’s mold, right? When it’s there you just see it and remove it. Why do we need to make it so complicated?

Mold Sample Testing

Well, there are a lot of different reasons. For starters, we definitely don’t always see the mold. Mold has the nasty habit of growing into places where we never look – the inside wall or corners of clothes closets or kitchen cabinets. The floor of a car, beneath the seats or behind the pedals. You know – the places where we don’t really stick our heads in.

And once mold starts growing into these places it can get out of control in a matter of days. Once that happens, a mold infestation can contaminate the air and lead to a lot of different respiratory problems, cause allergy reactions, and a lot more. Not to mention that it can be harmful to the surface it’s growing on as well (it is eating it after all).

Additionally, testing for mold helps with its prevention too. If you start noticing that the relative humidity level in your home has risen or you start smelling strange and unfamiliar smells – an air test for mold can give you a definitive answer.

What’s more, you also want to do some testing after you’ve just cleaned a mold infestation. Mold, and black mold in particular, can be really tenacious and reappear just after it’s been cleaned, either on the same spot or on several different spots in the same home. This is not a coincidence, as most home owners usually think – when mold is being cleaned, scrubbed or even just dried off with a fan, it has the nasty habit of throwing its spores all around the air. And once those settle down in a new place, the whole circus is ready to start again. That is why we always advise our readers thoroughly isolate the mold contamination when they are cleaning it – duct tape, plastic sheets, all that good stuff.

Yet, even if you’ve taken these precautions, mold reappearance is not rare, so testing for it a little after cleaning can give you a lot of useful info.

So, now that we know why we want to test for mold, the next question is:

​How ​Do We Identify Black Mold?

The first thing to do is look for some of the classical symptoms of a mold contamination. Look at any places with high levels of moisture – windows, outer walls, pipes in the bathroom or under the kitchen sink, as well as anywhere else, the air conditioner’s outer cell, and so on. Also pay attention to any strange smells – mold usually comes with its own distinct smell in the air which is how we usually find out about contaminations that are growing out of our sight.

Once you locate the mold or reach the conclusion that you have mold in your home somewhere, the next question is – what type of mold? Mold comes in a lot of different shapes and sizes, as well as virtually all colors of the rainbow. The color of black mold, for example, is quite self-explanatory – it is black. It has other distinct features too, however: black mold grows in a circular pattern. Patches of black mold look like they are made out of individual dots (which they are). When it is on a wet surface, black mold looks slimy. On a dry surface, on the other hand, it looks like soot.

We won’t go over the physical descriptions of all types of mold, since there are literally thousands of them. Physical descriptions can only get you that far. Just remember that not all black mold is toxic (in fact, most of it is not) and other types of mold can be toxic as well. Aside from that, if you want tips for battling a particular type of pink or red mold that may be different from the more regular black or green mold – look for them independently or call a professional.

Just looking and smelling for mold is not that effective, however. There are various tests and commercial test kits that can be used for air testing and surface testing.

Black Mold In House

So What Should You Do If You Want To Test For Mold?

The first thing we’d advise you is to simply call a professional. Not because you can’t do it yourself but simply because if you want to test for mold, this means you want a really thorough information. And the best way to get that is with the help of a professional. Besides, mold testing is the cheap part of a mold professional’s costs. When it comes to cleaning a severe mold infestation, that’s why the costs start piling up. If you are worried about the prices of professionals, we have an article on this website that goes over the cost of removing mold.

If you are certain that you don’t want a professional’s help and prefer the DIY method, there are plenty of different commercial mold kits that are sold for the home owner’s convenience. The way you use each of them is different and explained on the product. Once you take a sample with such a mold kit you get to send the sample to a professional mold testing laboratory and from there you will get back the results.

Keep in mind that when testing the air for mold it is always a good idea to conduct several separate tests over time. When it comes to mold spores in the air, their quantity always fluctuates, especially after a wild release from an area of mold contamination – the mold spores flow through the air and move around, so several tests can give you a much clearer idea than just one.

If you are wondering what the different types of mold tests are, they can be summarized in three groups:

  • Air testing
  • Surface testing
  • Bulk testing

Ideally, if you want to test your home for mold and mold spores, you should use all three types at the same time.

Mold Testing Equipment

Air Testing

Air testing for mold is rather self-explanatory – you take a sample of air and you send it to a professional lab for testing. As we mentioned, however, individual air tests can be unreliable since the amount of mold spores in the air can fluctuate from place to place and from time to time. Thus, conducting several different tests at different locations of your home and at different times is a good idea.

​Surface Testing

This method takes samples of the various surfaces in your home and sends them for testing of mold spores. Such samples can be taken by swabbing, tape lifting and other methods. In some cases, you can send the surface itself. Surface testing is particularly useful if you are worried about a specific area of your home – maybe a wall that used to be infected by mold in the past. Surface testing, however, can’t identify the amount of mold spores in the air of your home.

DIY Mold Test Kit

​​​Bulk Testing

​Bulk testing is done by directly taking pieces of material from your home and sending them in for testing and analysis. The materials are examined under a microscope and you are given a conclusive result on whether or not there are mold spores on them.

If, instead of testing for whether there is mold in your home, you want to test what type of mold you have, you can perform a​ culture test for mold.​​​​​ This is done by directly taking a sample of a mold contamination and sending it to a lab to determine the exact nature of the infestation. This is done for several different reasons:

  • If you are worried that you might be dealing with toxic mold.
  • If you want to know the exact type of mold so that you can combat it more effectively.
  • If you want to know whether the mold is dead or is still alive. There are some methods of dealing with mold that leave dead pieces of mold behind. Keep in mind, however, that even dead mold can still lead to health problems and allergy concerns.


And this is pretty much it – not too complicated, right? Well, if you are the one working in the laboratory, the process has a few more steps, but as a home owner you only need to take a sample of the air or of a surface and send it to a professional. Or just call a professional to come in.

Either way – good luck!

Leave a Comment:

1 comment
Add Your Reply