Have cracks in your basement floor?

Learn what you need to do to fix them and stop them from occurring in the future.

What Causes Cracks in Basement Floors?

Cracks in basement floors can be caused by a multitude of issues. They commonly have to do with either the moisture or water underneath the basement floor or a subpar foundation system that needs stabilization. Not all cracks in basement floors require fixing, but some can lead to or be a sign of larger underlying issues in your home or your building’s structure and foundation.

Types of Cracks in Basement Floors and Fixes for Them

Sometimes basement floors in old houses dry up and result in cracks. Cracks can also appear in newer houses.

It’s very important to identify the problem correctly, as a misdiagnosis could result in further damage in the future.

Here are the main types and causes of basement floor cracks:

1. Hairline cracks

Hairline cracks are smaller cracks in basement floors that have not opened and do not affect the structural integrity of your home.

Cause: Hairline cracks can be caused by changes in the temperature of the air and concrete, poor workmanship on the builder’s part, the type of chemicals mixtures used, relative humidity, and several other factors.

Fix: Hairline cracks don’t necessarily need immediate attention, but it’s good to keep an eye on them in case they open up into larger cracks. To fix hairline cracks, you will first need to clean the crack, apply a sealant, and then cure it to harden the sealant.

2. Heaving

When basement floors rise up, it is called “heaving”, and this can cause damage to your home.

Cause: Heaving usually occurs when the ground beneath expands and causes the basement floor slab and footings to rise up with it. When the basement floor rises, it can cause cracks which are destructive to your home.

Fix: Since heaving is oftentimes caused by unwanted water accumulation, the way to begin fixing this problem is by getting rid of that unwanted water. It can accumulate through improper drainage, evaporation, poor soil conditions, or transpiration. After identifying where the water is coming from, you can then put a system in place to keep the water out and maintain a stable foundation.

3. Foundation settlement

Foundation settlement occurs when the compression in your foundation is unequal. This can cause lots of repercussions, but one of these is cracks in your basement floor.

Cause: Foundation settlement is often caused by changes in the soil around a home or building. The soil that once supported the structure changes, and that can cause cracks in basement floors.

Fix: Basement Water Controlled uses a Stabil-Loc foundation piering system to fix foundation settlement issues. It’s important to place the anchors in the system properly and securely in order to safely secure and stabilize the foundation.

4. Water seepage

Water can seep in through the cracks of your basement floor.

Cause: Water comes in through large and small cracks of your basement floor. The soil and ground underneath your basement is filled with moisture, and at different times of the year and, depending on water levels and whether recent rain caused the basement leakage, it can lead to water seepage through cracks in the floor.

Fix: Smaller cracks do not always need to be fixed, but if water is leaking, it could be evidence that you need to update your drainage system. Some options are the dry-up baseboard system or a drain tile system. Larger cracks may be evidence of structural issues. In this case, it’s best to get it looked at by a professional.

Should I Fix the Basement Floor Cracks Myself or Hire a Professional?

You may think smaller cracks in your basement floor will be easy fixes, but that’s not always the case. Small cracks can get larger over time if not treated.

As a rule of thumb, anything larger than ⅛” should be sealed, and anything larger than ½” should be leveled.

Hire a Professional

Basement Water Controlled Team

If your basement floor has larger cracks, and you think it may be because of a larger underlying issue, call the team at Basement Water Controlled today, and we’ll send out an experienced estimator to identify if your basement is in need of repairs.

The Two Most Common Fixes For Basement Floor Cracks

The team at Basement Water Controlled uses a proven piering system to fix failing foundations and uses tested methods to safely and securely drain water from your home’s basement.

If you think your basement floor is in need of fixing, don’t wait to contact us.

Below are the most commonly asked questions about cracks in basement floors.

Will sealing one section of a basement floor cause water to come up somewhere else?

Before trying to seal your basement floor, it's important to diagnose why your basement is leaking in the first place. Simply sealing it could cause more issues than it resolves. It could lead to more cracks in your basement and also cause water to leak from new locations.


Q: Are cracks in concrete floors normal?

A: Cracks in concrete floors are not uncommon. They commonly occur because of changes in moisture and water in the ground beneath the foundation. Small cracks that are not “open” do not require fixing, but larger cracks and water seepage may be a sign of a bigger issue.

Q: What do cracks in the basement floor mean?

A: Cracks in the basement floor can tell lots of different stories. Sometimes the conditions in which the concrete floor was poured can cause smaller cracks, which do not affect the structural integrity of the home or builder. Larger cracks can mean that your foundation is not equally compressed or that the soil underneath the home or building is full of moisture and needs drainage work done.

Q: When should I be concerned about cracks in my basement floor?

A: Small cracks that have not opened do not require fixing. However, if the cracks are open, the floor is rising or sinking, or you have water seepage, it’s best to call a professional to identify your issue before it gets worse.

Q: How do you waterproof basement floor cracks?

A: To begin with, it’s always smart to have a drainage system in place that can rid of unwanted water. There are ways to fill cracks in basements, but larger cracks may be a sign of larger issues, such as foundation failure.

Q: How big of a crack is dangerous in the foundation floor?

A: Generally, you don’t want cracks in the basement floor to be larger than ⅛”, and anything larger than ¼” is enough to warrant a call to the professionals. It’s better to be safe than sorry.

If water is coming through the crack between the floor and wall, this is called cove joint seepage.

Our team has a tremendous amount of experience identifying what the issue of cracks are and what needs to be done to resolve them.

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