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So, you’ve noticed a crack in your basement wall, or maybe in your foundation itself. Should you be worried? Some cracks are merely cosmetic, and not a cause for alarm. Some cracks, however, can let in moisture or even threaten the structural integrity of your home. How can you tell the difference?

  • First, let’s talk about the cracks that are not cause for alarm. Sometimes, small vertical cracks form in concrete because it shrinks during the curing process. This is typically not a major issue and won’t affect the wall structurally. However, in some cases it could allow moisture to seep through the wall. Fortunately, these little cracks can often be injected with a sealer to keep the water out. If you notice a hairline vertical crack or even one as large as 1/16th of an inch, there’s probably no need for concern. On the other hand, if your basement has vertical cracks 1/8th of an inch wide or wider, this could be the sign of a problem. In that case, you should call in a professional to inspect the cracks and determine whether your foundation needs repair.
  • Horizontal cracks, on the other hand, can be a much bigger deal. This type of crack can be an indication that your foundation is unstable. If you notice that the wall bows inward and there’s a horizontal crack midway up, this is probably the result of hydrostatic pressure pushing your wall inward. If the wall is still straight up and down and you notice a crack, you might be able to take a wait-and-see approach and just monitor it for any expansion. If the crack continues to enlarge, though, don’t hesitate to call for help. Bear in mind that horizontal cracks are often caused by water collecting around the foundation, so you should check to make sure your yard is draining properly, with water being diverted away from the house. Not only can water seep through the cracks, but when water pressing on your foundation freezes, the ground will exert further force on the foundation and push it inward.
  • Stair step cracks are less concerning than horizontal cracks, but they’re still a problem. You might see these on your exterior walls and above your foundation. They typically happen in walls that are made of concrete block, rather than solid concrete, and they indicate a shift or settlement in the foundation. They happen because the blocks or bricks in the foundation have separated because of this shifting. Stair step cracks don’t threaten the structure of your home the way horizontal cracks do, but they can be a significant cause of moisture in the basement.
  • Diagonal cracks are very similar to stair step cracks in that they result from shifting or settling. The main difference is that while stair step cracks form in concrete block walls, diagonal cracks show up in concrete walls. Sometimes, the diagonal crack will start at the top of a basement wall and move down to a corner, often accompanied by inward tilting at the top of the wall. This happens when the earth is pushing against the wall and there’s an inadequate connection between the basement and the framing of the first floor. Sometimes, a diagonal crack can appear somewhere else on the wall, wider at the top than the bottom. This happens because of foundation settlement. If a diagonal crack forms at the corner of a door or window, it’s often due to the concrete shrinking as it cures, just like with vertical cracks. If you’re experiencing diagonal cracks in your foundation walls, it’s time to call in the professionals.
  • Sometimes cracks form in the slabs for the basement or garage. Have you ever wondered why sidewalks have joints? Those are created as a strategy to prevent cracks in the sidewalk, because concrete tends to crack in square sections when it hardens and shrinks. Even with control joints, though cracks can still form. As long as they’re tight cracks, they’re probably not a structural problem. But because basement and garage slabs are directly on the ground, if a crack is ¼ inch or wider or it’s higher on one side than the other, it probably means the ground below is unstable and you should call in an engineer.

Aside from concrete shrinkage, water around the foundation, and foundation settlement, there are a few other reasons that cracks may form in your basement. Soil can shrink or expand, causing the foundation to move. Large trees can cause the foundation walls to crack by sucking the moisture out of the soil with their roots. Additionally, when a house is built with poor materials or without proper understanding of the soil, it’s likely to crack. The soil must be tested before the house is constructed, because it might not be sufficient for the weight of the house. Similarly, when a new level is added to a house, it becomes heavier, which can also impact the foundation.

No matter what kind of crack you’ve noticed, there are a few signs that point to a serious problem. If the basement walls are leaning, tilting, bowed, or bulging, it’s a situation that warrants calling an engineer. If the crack has a V shape, moving from the bottom of the wall to the top, and widening as it goes further up, this could indicate differential settlement. Often considered the worst kind of settlement, differential settlement happens when one part of the foundation stays in place and one part shifts or drops lower. This can cause significant damage to the foundation and the home. Cracks that shift so that the wall becomes misaligned, or that run through the wall and floor continuously are also problematic. If a crack is ½ inch or wider, that’s an indication of a structural issue. On the other hand, even a small crack can become a problem if it continues to grow. When in doubt, it’s always best to have a structural engineer take a look at your house.

What’s the solution to cracks in the foundation? They need to be fixed quickly so that water doesn’t seep in and cause severe water damage. Another danger, of course, is that the cracks can compromise the structural integrity of your home. Further, pests like termites and rodents can enter your home through foundation cracks. The right fix will depend largely on the crack and what’s causing it. Having a foundation repair contractor come and inspect your basement or foundation is prudent, because they’ll know which solution will work for your particular problem. Wall anchors may be sufficient to stabilize the foundation wall, or a foundation may need underpinning to stop it from settling vertically. If the cracks are merely cosmetic, an epoxy injection will take care of the problem. Getting someone with experience in this area to take a look at your problem is the best way to make sure the right repairs are performed in the right way.

If you’ve noticed cracks in your foundation, Budget Waterproofing can help. In addition to waterproofing, mold remediation, mold cleaning, and crawl space encapsulation, we provide foundation repair, going beyond patching cracks to find the source of the problem. We also offer installation of the EZ Breathe home ventilation system, to clean the air inside your home. At Budget Waterproofing, we’ve got more than 55 years of experience servicing both commercial and residential customers throughout Maryland. We’re proud of our craftsmanship and confident in our skills, and all of our technicians are fully licensed and insured. Whether you need foundation repair, basement waterproofing, a drainage system, crawl space waterproofing, or egress window installation, we’ve got you covered, with the experience and skills necessary to improve your basement and protect your family. For more information, contact us today.