What Causes Cracks in Basement Floor & How to Seal them?

Cracks in the basement floor might not lead to some serious issues because the basement floor does not bear the burden of the house as the walls of the basement do.

But it does not mean that you should not pay attention to the cracks in the basement floor. There is no need to repair minor cracks as these do not affect the structural integrity of your house.

There might be some cracks that are a sign of some serious issues so do not let these cracks unattended and go ahead with sealing basement floor cracks.

In this article, you will learn different causes of basement floor cracks as well as you will learn to fix these cracks. If you are facing any issues with your basement floor then continue reading this article. You will end up gathering the entire information. So let’s get started.

Basement Floor Cracked and Raised

Basement floors do not interact more frequently but they can damage or get cracked with time.

If the age of your house is increasing then basement floor cracks are common but the places where the cracks appear determine that are these are dangerous or not. If it is near the foundation walls then it can cause serious issues to your house.

You should repair these cracks in the beginning; otherwise, they can cause holes in the floor.

What Causes Cracks in Basement Floor?

To cure the problem you just need to know the cause. If you have an idea about why the cracks occur then you can take steps to fix them accordingly.

The most common causes of basement floor cracks are the following.

  1. The most common cause of basement floor cracks is shrinkage. The floor contains water and cement6 that gets solid with time and shrink as well. The shrinkage depends upon the temperature of the basement. If the temperature is low while you are curing then it can cause cracks on the floor.
  2. If the soil under the floor is unstable then it can cause settlement issues that lead to cracks in the floor.
  3. The gaps between walls and ceiling cause cracks
  4. The distance between the floor and walls lead to cracks in the floor
  5. The frost heave in the cold season also causes cracks in the floor.

How to Fix Hairline Cracks in Basement Floor?

Hairline cracks are a type of cracks that are not serious and do not lead to big issues. It can cause shrinkage of the surface of your floor when it dries. It can appear approximately one year after the floor is made. The cracks can be small that does not need any repair but if these are wider than 1/8 inch then it should be repaired quickly. You can fix hairline cracks on the basement floor as follows.

  1. Clean the debris from the surface of the crack.
  2. Take a garden hose and dampen the crack.
  3. Take a bucket and mix vinyl concrete patching compound with water.
  4. Be sure to follow the direction on the packet.
  5. Press the solution on the crack and fill it until it gets plain. You can use the flat bottom of the trowel to make it plain.

How to Seal Basement Floor Cracks?

Basement floor cracks should be first examined to discover the cause and then any action should perform.  It can be most commonly due to wear and tear. You can seal basement floor cracks as follows.

  1. Remove the pieces of concrete and any debris from the cracks. So the crack is fully exposed to you.
  2. You can vacuum the area to make sure that there is no debris left.
  3. Apply concrete patch on the crack.
  4. There should be no gaps and uneven areas left.
  5. Take a putty knife for smoothing the patch. Wait until it dries and then apply the second coat in the same manner. And at the end, you will get a plain and fresh basement floor.

Cracks in Basement Floor Leaking Water

The soil near the basement floor may contain water and when the cement is poured into the area, it creates cracks on the floor due to which the water starts coming above the floor.

This problem usually happens when there is rain for a long period. The ground is oversaturated with water and comes to the basement floor by causing cracks on the surface.

If you have an old house and do not contain any weeping tiles then the water finds a way from the basement floor and starts leaking through the cracks.

You need to make your basement waterproof to prevent such issues. And if the issues happen then you should first waterproof the basement floor and then fix the cracks as said in the previous section.

Waterproofing Basement Floor Cracks

When the basement floor gets cracks then it can cause several issues like the water in the rainy days can come above the floor from the cracks. You should fix it to prevent such issues.

You can waterproof the basement floor cracks in the following two methods.

  • Concrete patches
  • Foundation piers

You should discuss both the suggestions with a professional contractor to help you waterproof basement floor cracks.

When to Worry About Cracks in Basement Floor?

As told you that the cracks in the basement floor do not lead to serious issues but if the cracks are wider than 1/8 inches then you should worry about it and take action to repair it as soon as possible.

If the crack starts getting wider with time then you should be worried. And if they are near your home’s foundation walls then immediately contact the contractor to resolve the issue.

How to Avoid Cracks in Basement Floor?

In the previous sections, you have learned to seal basement floor cracks, but you should also take steps that these cracks could not even occur.

You can avoid basement floor cracks in the following manner.

  1. You have to properly cure the floor and give appropriate time so that it can get dry completely.
  2. Add control joints in the concrete so that there will be no space for cracks left.
  3. Be sure to use an adequate amount of water while pouring cement on the surface. If the water amount exceeds then it can lead to cracks.
  4. Compact the base to secure the slabs.
  5. Use steel reinforcement on the floor to make it stronger.


In this article, you have known about sealing basement floor cracks and can now fix this issue easily.

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