Why Do Cracks Form in Basement Floors?
First, the good news about discovering a crack in your concrete basement floor is that basement floors don’t actually support or stabilize the weight of your home the way that the walls of your basement do. Most basement floors will form hairline cracks at one point or another. In fact, most new houses will get basement cracks within the first year following construction. Typically, a basement crack is simply a superficial and isolated imperfection that is not a telltale sign of a bigger structural issue. Most cracks that you’ll encounter were simply caused by your home settling. Poor construction, shrinking of concrete and general stress can also cause cracks. Again, these cracks are typically not harmful. However, you could be in trouble if the crack that’s formed in your basement floor is the result of a soil issue that’s taking place under your house. When the soil under a home becomes wet due to water pooling or excess moisture, it can expand enough to actually push up against your basement floor to form cracks. If you’ve noticed a “heaving” crack, there’s a good chance that you have a soil-related crack. This is more likely if you live in an area where homes are built on clay soil.
The Problem: Basement Concrete Floor Hairline Cracks
A hairline crack is a small stress crack that doesn’t require intervention. If you’re bothered by the look of a hairline crack in your basement floor, consider a cosmetic solution like carpeting, tile or faux wood-plank flooring. If a hairline crack is a wall-floor joint crack, you can often take care of the problem by sealing the crack to keep moisture issues away.
The Problem: A Crack That’s Bigger Than a Hairline Crack
If the crack you’re staring at is 1/8 of an inch or larger, an intervention is usually recommended. The best option is to seal the crack using a sealant made for concrete and masonry. While this is typically a do-it-yourself job, you can also bring in a flooring expert to handle the job. Sealing a crack of this size helps to keep out moisture and smells that seep in from the ground. Sealing also protects your home from potential radon seepage. If you’re concerned about this, it’s a good idea to bring in a professional to have your home tested for radon.
The Problem: A Crack That’s 1/2 of an Inch or Larger
If the crack you’ve found measures in at 1/2 of an inch or larger, a more serious intervention may be needed. This could be a sign that a part of your slab actually sank a bit during the settling process due to a lack of support. You’ll notice that the crack may be a bit “uneven” when you glance at it. If this is the case, you’ll still have an uneven surface that creates a hazard for tripping even if you do seal it in. You’ll also need to level your floor before applying new flooring to cover the crack. Luckily, leveling a basement floor isn’t all that complicated. You can typically do the job yourself using a special injectable leveling formula that will help you to build volume back into the slab. When injected into small holes that you drill into the slab, this formula has a lifting and stabilizing effect. Again, this is something that any flooring professional should be able to help with if you’re not interested in a do-it-yourself fix.
The Problem: A Heaving Crack
If you’re noticing that a floor crack is accompanied by some heaving, there’s a good chance that your floor needs a corrective intervention. When we see heaving, the soil under your floor is actually expanding due to moisture. That moist, heavy soil gets enough weight and pressure behind it to actually push up against your floor to create cracks. Unfortunately, you probably won’t be able to address a heaving crack caused by expanding soil completely on your own. The best option is to bring in a contractor to assess the situation for you to determine if pressure from your soil is behind the crack. There’s a chance that improper drainage around your home could be the reason for the crack. If this is the case, you’ll need to consider some landscaping and drainage options to prevent more cracks from forming in your basement floor.
The Problem: Surface Flaking
You may be perplexed by flaking that you’re seeing on your concrete basement floor. While this can look troubling, it’s actually a common issue that is caused by your builder using a concrete mix that was too wet when pouring your floor. This is a superficial issue that isn’t indicative of the state of your actual slab. However, many homeowners who are bothered by this unsightly problem find that finishing their basement floors with tile, faux wood, carpeting or linoleum takes care of the issue!
Final Thoughts on How to Fix Cracks in Basement Floor
The good news is that most cracks in your basement floor are purely superficial. That means that the solution for how to fix cracks in basement floor really comes down to finding an attractive way to cover your floor. For many homeowners, an unattractive crack simply provides a good reason to bring in some durable, basement-friendly flooring. This can help to bring a more relaxing, attractive and finished look that will make you feel confident about showing off your basement without worrying that harmless cracks are making your home appear damaged.