How To Check And Test For Mold In Basement

How do I know if I have mold in my basement? Here is how to check and test for mold.

One of the biggest concerns for homeowners regarding their basements is water seepage. Water in the basement can cause several types of problems, and one of the most common problems is mold growth.

Under damp and dark conditions, mold spores only need between 24 and 48 hours to begin to grow. Their colonies also begin to form in about 12 days, and they become visible in about 18 days.

If you’re currently experiencing water seepage in your basement, or there’s just been flooding, then you would do yourself a favor by going into your basement and checking for mold growth.

Don’t worry if you have no clue what to do, I’m here to help. This is why I’ll be walking you through how to check and test for mold in the basement.

All you have to do is read to the end!

Why You Should Check For Mold In Basement

If you’ve never had to deal with mold before, then I can understand why you don’t consider mold growth as a crisis. Well, it is, and I’ll be giving you several reasons why.

First of all, mold looks terrible, so if you allow it to grow on your basement walls, ceilings, and floors, your beautiful living space will turn ugly and unappealing.

Keep in mind that you will have to spend hundreds or thousands of Dollars removing the mold, repainting the walls, and restoring your basement to its glorious looks.

An early inspection can save you from these inconveniences.

The second problem with mold growth is far more serious than bad looks. Mold has been proven to be a health hazard. They can cause all sorts of allergies on the skin and throat and can infect human lungs and make breathing problematic.

Lastly, mold produces a terrible musty smell, which can make life uncomfortable in your basement. The smell is worse when the mold colony is full-blown.

You can avoid all the health and aesthetic problems that mold causes simply by testing for mold in the early stages.

When Should You Check And Test For Mold In Basement?

Always check and test for mold in your basement after any of these incidences.

After basement flooding: Did your basement just get flooded by heavy rains? If the answer is yes, then the first thing you need to do after drying up the water is to check and test for mold.

Mold spores only need 24 to 48 hours to start growing, so waiting longer than you should mean that the mold colonies are already being formed.

When you notice leaking pipes: If you come across a leaking pipe in any plumbing above your basement ceiling, then take a careful look around to see if there are more leaking pipes.

If there are basement leaks, then there’s a great chance that the water has been flowing down into your ceiling or down your basement walls. If the walls or ceilings are wet for extended periods, then mold will grow on them.

If there’s always standing water outside your foundation walls: Do you keep seeing pools of water by your foundation walls? If you do, then you better hope there are no cracks along the outer foundation.

Water will seep through into your basement if there are any cracks, and will make your basement a good environment for mold growth.

That being said, be sure to check your basement for mold growth once you notice standing water outside your foundation.

If water comes up from the basement floor: Doe those who don’t know, hydrostatic pressure can push water from the soil up through your basement floor.

So if you ever notice a crack in your basement floor with some dampness, then it’ll be best you conduct a mold inspection and test before the colonies begin to grow.

Now that you know when to check for mold, let’s get right into the process!

How To Check For Mold In Basement

One of the most annoying things about mold is that it can grow anywhere and you may not even know! They may have been growing in your basement for a few months and you’ve never seen any.

Well, that’s why a thorough inspection is very necessary.

Here are the steps you need to take when checking for mold.

Step one: Identify the signs

As far as mold detection is concerned, one of the best ways to sniff them out is by being able to tell the signs of their presence. Your ability to identify these signs even without physically seeing the mold will go a long way in your mold remediation plans.

So what are these signs? There are two major ones you should pay attention to.

The first of these signs is a musty smell. So if you notice this odor anytime you walk into your basement, then you can be sure mold is growing in there somewhere.

To confirm, walk into your basement and spend about 30 seconds in there, then walk out into another room and observe if the smell persists. If it doesn’t, then you can be sure that the mustiness is coming from your basement.

Another sign that can be used to tell if there’s mold in your basement is your physical reactions.

Mold can cause allergies and breathing problems, so if your skin feels funny or your breathing is heavier than usual anytime you’re in the basement, then that’s a sign that mold is present.

You can also confirm this by carefully observing your physical state when you’re in and out of the basement.

Step two: Visibly identify the mold

As I just mentioned, mold may have been growing in your basement for months without being visible. This is because they can grow anywhere there is dampness and warmth.

This means if the wall behind your couch has sustained dampness, there could be mold growth there without your knowledge.

With this in mind, you can start your search by moving all furniture that is leaning on your basement walls to see if there’s any mold growing there. Mold can also be growing behind hanging pictures, so take them down and look.

If you have wallpaper and you suspect mold growth on your walls, then you will need to tear the wallpaper down and inspect it.

Don’t forget to raise your rugs to see if there’s mold growing under there.

Visual confirmation is the best way to check for mold, but if you can’t find any after having a thorough look, then you may need to try another approach.

Step three: Drill through the concrete walls

If you can’t physically see the mold but you’re sure it’s in your basement (due to the musty smell or your physical reactions), then you may need to take more drastic measures.

One of such measures is to hire a professional contractor to drill some parts of your concrete basement wall. This will indeed consume time and money, but you need to do the needful to eliminate dangerous mold from your basement.

But why drill the walls you ask?

Concrete walls may be strong but that doesn’t make them mold-proof. This is because concrete walls have tiny pores on them which allow moisture to seep through. And if it remains damp for long periods, mold will begin to grow inside the walls.

So yes, it’s possible to have mold deep inside your concrete walls without appearing on the surface.

The good news is you don’t have to tear down the entire wall to identify internal growth, just drill through a part of the section where you suspect the mold growth.

Use a flashlight to look into the hole to visually confirm the growth of mold within your basement walls.

How To Test For Mold In Basement

Mold testing is quite similar to mold inspection, as both concepts aim to confirm the presence of mold in an environment. And while a rookie can check for mold in the basement, testing for it will require a more professional touch.

  • Basement Mold Test

Mold testing simply means using a mold test kit to collect air or surface samples where the mold is suspected to be growing but not visible.

The samples are then taken to a laboratory, where they will be tested to determine the species of mold that exists in the area.

As I said before, mold testing requires a more professional touch for accurate results, so don’t bother doing it yourself, even if you have a test kit.

Don’t worry about the cost of professional mold testing, it isn’t that expensive. You’ll need a budget of around $150 to $250 for low-end testing.

You can also skip the tests in some instances, especially when you can already physically see the mold.


Checking for invisible mold in your basement is an important step to take if you wish to control the growth of mold colonies.

Follow the tips provided in this article to ensure that mold doesn’t grow unnoticed inside your basement.

Good luck!

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