We were recently featured on the acclaimed radio show House Talk.

Are Cracks in my Basement Floor Normal?

Are Cracks in my Basement Floor Normal
Are Cracks in my Basement Floor Normal

Especially for new homeowners, cracks in the basement floor can be scary. And depending on the situation, it can be justified. I mean, a big crack in concrete wasn’t designed to be there, was it? In some cases, it actually was! Other times there are outside factors coming into play. Here are a few main reasons that floor cracks appear in your home:

  1. Normal Settlement. Far and away the most common. A large, thin (4” on average) slab of concrete is poured for your basement floor. While sitting on dirt helps give it support, it receives little support laterally from the concrete itself. Let me paint a picture. Start sliding that concrete slab over a cliff. Eventually, that slab will crack and break. The same concept applies here, but over a longer period of time, and less severe. These cracks are normal and found in almost every basement. Many times, builders will “pre-crack” them. If you see your basement floor is split into large squares, this is for you. This is done so the cracking happens in nominal spots so it looks on-purpose. These cracks do not need to be repaired, unless you have Radon Issues. Then a simple bead of caulk is more than enough.
  2. Foundation Settlement (Abnormal Settlement). Different scenario. Now your home is settling. . As the home sinks into the ground, it will take the basement floor, and the floors above for that matter, with it. This will cause cracks along the floor that will correspond to cracks on the foundation wall. Think the Titanic breaking as it sank into the ocean. That crack where the ship split (similar to where your house splits in these cases) is the stress point at which the house pulls apart. These cracks need to be addressed, and more specifically, your foundation needs to be addressed.
  3. Hydrostatic Pressure. In some extreme cases, water pressure from underneath the floor (due to lack of drain tile, high water table, monsoon rains, etc.) can literally push the floor up, like a zit on a teenager in High School. In the most extreme cases, the zit pops. I’ve personally seen it over a foot high, which then geysered and flooded the basement. Not what you want to walk down to in the morning. In these cases, the floor needs to be replaced, and an effective Drain Tile installed.
  4. Roots. Most commonly found on slab-foundations, these growing trees can push your floor up, causing “speed bumps” in your garage or slab. These roots can even lift your foundation! There is only one way to deal with it, cut the roots and replace the floor. You have to stop the roots from growing, otherwise it will just happen again. And yes, we all love that big tree in the yard, but when it is within 10 feet of the home, you are risking the largest investment of your life (your home).

Stitching Them Together

When we do approach repairing these Floor Cracks in the Basement or on your Slab Foundation, we are first repairing the underlying issue. Weather it be settlement, roots, or hydrostatic pressure, we need to stop the underlying cause so we can make sure the repair sticks.

Once that issue is handled, we can “stitch” the crack together much the same way that we stitch together a cut on our bodies. Instead of silk, catgut, or synthetic materials, we use Carbon Fiber Crack Locks (Carbon Fiber Staples for Foundation Crack Repairs). These are stitches for your foundation and will help reinforce the crack repair. They even look like stitches!

Main thing is to FIRST determine WHY you have cracking in your floor. “Suave” salesmen will come in and convince you the sky is falling and your whole world is about to fall apart. Most of the time we come in after these “Glen Garry Glenross” sales reps and find that the crack is from normal settlement and is not an issue. Do not let sales reps scare you. Get another opinion. We pride ourselves on our honesty, just saying.

Thanks for reading, and as always:

“Not Everything’s Better When Wet”


Austin Werner

Austin Werner is the Owner of The Real Seal LLC, a basement waterproofing and foundation repair company. Austin believes that having a highly trained and happy team is the key to success. This is reflected through hundreds of 5 star customer reviews his company has received online.

Leave a Reply

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



2 Way To Level An Uneven Basement Floor

2 Way To Level An Uneven Basement Floor

If you want to know how to level an uneven basement floor, this is the article for you. Many online…
Foundation Leveling: Methods, Cost, & More

Foundation Leveling: Methods, Cost, & More

If you want to know more about foundation leveling, this article is for you. We’ve compiled all the information you…
Why Mudjacking DIY Projects Are Always A Bad Idea

Why Mudjacking DIY Projects Are Always A Bad Idea

If you want to know why mudjacking DIY projects are a bad idea, you’ve landed on the right page. In…