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3 Horizontal Foundation Cracks That Should Worry You


Foundation cracks are detrimental to the value of your home, and horizontal foundation cracks are the worst of them. The foundation repair industry comes across these cracks often but sometimes encounters those that have completely altered the integrity of the home. In this article, we will be covering the different types of horizontal foundation cracks, where they typically appear, and what it means for you as the homeowner.

Horizontal foundation cracks can range anywhere between 1/32 of an inch to a full inch in separation. These cracks can be due to several factors pertaining to the structure and the outside environment, such as temperature, moisture, or weight disbursement. When these cracks show themselves, it is in your best interest to address them immediately, either by yourself or through a trusted foundation repair company. Addressing it yourself could lead to the problem persisting and only cause more damage down the line, while contacting a foundation repair company will result in expert solutions for a one-time cost that can be paid off in one lump sum or throughout the year in payment installments. Here are a few examples of the typical horizontal foundation crack in various stages:

Stage One: Emergence (1/16-1/8 inch)

horizontal foundation crack

We are including this stage because this is when a crack will typically be noticed by you, the homeowner. These cracks are considered hairline horizontal cracks and typically start to show up in the interior basement or crawl space of the home especially if the foundation of the home is comprised of a slab or a concrete base. Sometimes, these cracks will present themselves on the exterior of the home, often when the foundation is comprised of brick and mortar. When these cracks do show up on the outside of the home, it is typically due to several factors such as:

  1. Cold climates – During the winter months in the Carolinas, the frost line, or the depth at which groundwater freezes, is 10 inches in North Carolina, while in South Carolina, that depth is 4 inches. This freezing depth can affect your foundation’s exterior and cause cracking to form based on what depth groundwater resides around your house.
  2. Inadequate water drainage – If your home lacks the proper grading and fails to push water away from your foundation, that water can gather at the base and put immense lateral pressure on your home during times of flooding and rainfall. This strong lateral pressure will cause your foundation walls to buckle and crack at the point of contact.
  3. Overloading – Although not a likely culprit, sometimes when a large weight such as a truck and trailer are weighed down and are constantly being driven near the foundation of the home, it can cause cracking at the upper third of the interior foundation wall, which will be the lower third of the exterior wall.

When you encounter this stage of foundation crack on the exterior of the home, since it is horizontal in appearance, the best course of action is to keep monitoring its progress. Small cracks like these are shrouded in mystery because they could either mean there is nothing wrong, and other times it could mean that there is a serious structural issue occurring. Therefore, while monitoring the crack, you should also consider calling a foundation repair company to inspect the area and give a proper diagnosis.

Stage Two: Progression (1/8–3/4 inch)

horizontal foundation crack

We are including this on the list because anything after one-eighth of an inch in width could mean trouble for you and your home. At this point, you have monitored the hairline crack and realized after a couple of weeks that it has progressed significantly. Progression like this can mean a certain level of shifting has taken place or possibly a big storm just blew through, causing your foundation to take on more water pressure than normal. Horizontal foundation cracks progress if the issue causing the crack in the first place isn’t corrected. In this case, there are several contributing factors that you may have missed, such as:

  1. Foliage and tree systems – Most homes have some form of foliage or tree system running underground, which stabilizes the soils around your home. Also, their roots can grow into the home if the position of the tree or bush is too close to the foundation.

Caution: Removing trees abruptly can affect the soil conditions surrounding your home and can possibly make the problem worse.

  1. Construction sites nearby – Just like an earthquake shakes the ground and aftershocks send vibrations through the earth, a nearby construction site can do the same thing while operating heavy machinery. That machinery will send vibrations through the earth, and if you already have a cracking issue, these vibrations can possibly contribute to its progression.
  2. Degradation of building materials – If you live in a relatively old home, the progression of a horizontal foundation crack can possibly be the building materials that make up your home are breaking down due to age or poor maintenance.

When a horizontal foundation crack progresses into stage two, the best course of action is to contact an expert foundation repair company to come and inspect the issue, locate the origin of the problem, and provide an option and solution to correct it. A crack of this magnitude could be the beginnings of a serious problem making it imperative that experts be contacted immediately.

Stage Three: Severe Shift (1 inch-plus)

severe horizontal foundation crack

We chose to include this level of horizontal foundation crack because it is the most damaging to your foundation and home. If a crack has gotten just as wide as the tip of your index finger, there are some serious structural issues. A crack of this magnitude can present itself as a regular horizontal crack that spans across the footing of your home’s foundation, or it can be a combination of a horizontal and vertical crack. These cracks are known as “stair-stepping” cracks. They typically appear after a period of shifting occurs and can bring your house to the point of collapsing. A large episode of shifting in your foundation can be caused by several factors, such as:

  1. Lateral water pressure – Hydrostatic pressure is the amount of force that water puts on the walls of your foundation, and if your foundation cannot withstand the amount of pressure being laterally exerted upon it, it will start to cave in and collapse.
  2. Natural disasters – Earthquakes are natural disasters that can’t really be predicted, but they can cause some serious damage to your home. An earthquake will shake and rattle the ground. If your home, like most homes, is not prepared, then severe shifts can occur, greatly increasing the chances of total foundation failure.
  3. Soil conditions – 60% of all homes in the U.S. are built on clay soil, which leads to 2 to 3 inches of seasonal movement. This movement can be caused by the soil not being strong enough to support the structure, the soil is affected by groundwater erosion and therefore affects the stability of your home.

We have covered more than a fair share of causes to different stages of horizontal foundation cracks, and we have mentioned contacting experts throughout this post. The team at Carolina Foundation Solutions are those experts, and we are a trusted and top-rated foundation repair company that services both North and South Carolina. We aim to evaluate your property effectively and provide the best solutions in the industry to get your house back into a strong and stable shape. If the possibility of cracking, sliding, and shifting foundations keeps you up at night, contact Carolina Foundation Solutions for a free inspection. 

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