I’ll be using this article to teach you how to test your basement for moisture. I’ll also be telling you why it is important you test for it, and when you should test for it.

If you’re a homeowner in the United States, then basement moisture is something you have probably had to deal with at least once. This is because the basement is the lowest point of the home and the most susceptible to water.

The unfortunate part is, you may not even notice basement moisture until it has done some real damage, which of course will cost you a lot of money in repair.

That being said, it is very important to always test for basement moisture, especially when you notice a couple of glaring signs.

Yes I know, not everyone knows how to test for basement moisture, and you’re probably one of them (which is why you’re reading this article in the first place).

Keep reading!

Why You Should Test For Basement Moisture

Testing for basement moisture is something you would be mandated to do at one point or the other. Failure to oblige could mean putting the integrity of your structure at risk.

Here are a few good reasons for you to test for basement moisture.

  1. Water Always Flows To The Lowest Part Of A Surface Or Sub-surface

We all know that water usually follows the route of the most minimal resistance until it cannot flow anymore. And since the basement is the lowest point of your home, it means it is the most popular destination for water.

Flooding in the basement after heavy rain is very common, but it can also pool due to leaking pipes in-between the walls of your home.

For the simple fact that the basement is the most prone to water, it is vital to carry out regular moisture tests.

  1. The Basement Is One Of The Most Unvisited Areas In The Building

Areas like your kitchen, bedroom, and living room receive a lot of human traffic daily, but the same cannot be said of your basement.

Unless you use your basement as a workspace or living area, then chances are you only visit once in a few months. And for that reason, you will not be aware of what goes on down there with regards to water damage.

This is why you need to conduct regular moisture tests in the basement, especially after a heavy storm or major leakage in the house.

Doing so will spare you the inconvenience of having to spend more money than you need to by the way of structural repair and property replacement.

  1. To Tackle Leftover Moisture

After a heavy downpour, a basement that hasn’t been waterproofed will definitely get its fair share of water. You could pump the water away, but that doesn’t mean all the moisture is gone.

There are so many materials in the basement that can absorb moisture. These include the walls, ceiling, floor, carpets, and furniture.

If you do not conduct a moisture test after such an event, these materials that have absorbed so much moisture will begin to wear and tear.

  1. To Prevent Mold Growth

If you’ve ever had to deal with a mold infestation in the past, then you will agree that it isn’t a pleasant experience.

In case you didn’t know, mold spores love to land in moist environments where they can grow their colonies, and if your basement is full of moisture, then it’ll be just right for them.

Several problems are associated with mold growth. First of all, they don’t look good and can mess up the beauty of your basement.

Secondly, mold is very dangerous to human health. Some mold species are known to be toxigenic, while others can cause skin allergies and rashes.

Mold exposure can also lead to lung infections and worsen an already existing respiratory problem.

Knowing how dangerous mold can be, and knowing that they are attracted to moist areas further justifies why you need to carry out regular moisture tests in your basement.

Here is how to test for basement mold.

How Often Should You Do A Moisture Test?

There is really no specific time frame for doing moisture tests in the basement. However, some events would warrant one.

These include –

  • After heavy rainfall
  • After a major leak in the home has been fixed
  • When you suspect mold growth
  • When your basement smells damp for long periods

After heavy rainfall: When you experience a heavy downpour, you should expect that some water will get into your basement.

If your basement is flooded, clear out the pool and do a moisture test immediately so you know the levels of leftover moisture you’re dealing with.

After a major leak in the home has been fixed: If you just recently fixed a major plumbing issue, be it from the bathroom, kitchen, or laundry room, then you should assume that some of the water leaked into the basement.

Once the plumbing has been fixed, it would be in your best interest to conduct a basement moisture test at once.

When you suspect mold growth: If you walk into your basement and you perceive a musty smell, or you find it difficult to breathe, then there’s probably some mold growing in there.

Keep in mind that not all mold growth is visible, and it could be spreading within the walls. For this reason, it will be wise to carry out a moisture test just to confirm that the environment is actually conducive to mold growth.

When your basement smells damp for long periods: If you always perceive a damp smell anytime you walk into your basement, but can’t physically see any pools of water, then you need to do a moisture test.

As I have mentioned before, cleaning out a flood doesn’t mean that all the moisture is gone, as it could be trapped inside the walls, floors, carpet, and even furniture.

How To Do A Basement Moisture Test

Now that you understand the importance of doing a moisture test, and when you need to do it, let me show you exactly how you can go about it.

  1. Use a hygrometer to check the humidity

When humid air makes contact with cold water pipes or cool basement concrete, the result is condensation.

Humidity levels can reach as high as 90% when sustained in an enclosed space. To confirm this, you can use an electronic hygrometer.

You can find this tool in most home improvement stores near you. They are cheap too, they shouldn’t cost you more than $20 to get.

If your hygrometer reads humidity levels to be 60% or above, then use a dehumidifier to bring it down to 50% or less.

  1. Test for water infiltration

Concrete walls are porous, and when outdoor water permeates them continuously, it keeps the inner parts moist.

Here’s how to check for moisture inside your concrete basement walls.

Place a one-foot square aluminum foil to your concrete basement wall and keep it in place with duct tape. Ensure that the tape covers all four sides of the foil to the wall.

Leave the foil in that position for a few days, then inspect the outer parts of the foil afterward. If droplets are coming out of the outer part of the foil, then the humidity and condensation levels in your basement are high.

Peel the foil off the wall then check for moisture on the inner part. Also, check the underside for darkened concrete caused by excess moisture.

After you have confirmed that outdoor water is seeping through your basement walls, be sure to take steps to waterproof before it gets out of hand.

  1. Examine the plumbing

The thing with pinhole plumbing leaks is that they are small but mighty, as they contribute greatly to damp environments in the basement.

You should check your water supply lines for leaks, as well as mineral content in water like rust. Don’t forget that even the smallest leak can lead to a major pipe rupture.

A plumber can help you fix the leakages in your home.


There’s hardly a homeowner that hasn’t had to deal with water problems in the basement at one time or the other. The basement sits at the low end of the home, and it’s only natural that water flows downwards.

Since water in the basement can damage your property and create a breeding ground for mold, it is of utmost importance that you keep it out.

Identifying the moisture levels in the basement will give you an idea of how much of a water threat your building is faced with, and prepare you to take steps to remedy the situation.

Remember to test for moisture after heavy rainfalls, after fixing a major basement leak, and when you perceive damp or musty smells.

I hope this article on how to test for basement moisture has been helpful.

Take care!

Leave a Reply

Your email address will not be published. Required fields are marked *