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Everything You Should Know About Types of Foundation Cracks


All buildings need solid foundations. They help to disperse the weight of the building’s inhabitants, their possessions, and the building’s components to the ground below. A building’s foundation also prevents the ground underneath and surrounding it from shifting the structure. Finding a problem with the foundation should so cause you great alarm. Assessing the severity of foundation problems is critical since they are among the most costly to fix. In the case of foundation issues, some call for cosmetic fixes, while others need the assistance of an expert. Here, we’ll review the types of foundation cracks and how to troubleshoot them.

Horizontal Cracks

Basement foundation cracks running horizontally are a major cause for concern. In most cases, hydrostatic water pressure pushing against your foundation wall and soil imbalance are the culprits behind this kind of crack. You could find that water is seeping into your basement and that the foundation is bending inwards. Horizontal cracks may develop in both poured and block foundations.

Below grade, around the frost line, horizontal cracks are prevalent in the United States and are often the result of repeated freezing and thawing. A horizontal crack might develop in your foundation wall due to the uneven pressure that builds up over time.

Quickly get perspectives and repair solutions by calling several foundation crack specialists. Fortunately, a permanent solution to horizontal cracks comes with a lifetime warranty and may be transferred to a future homeowner in the event of a sale.

Foundation Slab Cracks

Cracks may appear in poured concrete slabs as time goes on. The difficulty is in determining the cause of the foundation slab break. Three typical reasons are:

  • The concrete slab’s drying, settling, and curing is the most typical cause. It is mostly aesthetic and does not constitute a structural hazard.
  • If your brand-new foundation slab has settling problems, you’re in a world of hurt. Soil problems or sloppy construction that failed to compress the supporting ground might be to blame. Quickly contact foundation crack specialists to do an inspection.
  • Foundations for crawl spaces that are slab-on-grade or higher are susceptible to frost heave. The concrete under the slab may buckle if the water beneath freezes.

Get in touch with a foundation specialist for assistance on the root cause and repair alternatives if the crack is wider than a hairline.

Stair Step Cracks

The stair-step cracks are common in block foundations. The stability of your basement’s base is jeopardized when cracks like this appear along mortar seams. The two most typical reasons for types of foundation cracks in stair treads are:

  • The sinking or settling of a foundation in a single spot
  • Concerns about moisture outside of your home’s foundation.

Call foundation crack specialists for an expert assessment and repair alternatives if you can insert more than a quarter into the foundation crack. Hairline cracks in masonry are frequent, but anything bigger is cause for concern.

Hairline Cracks

Foundations of newly built homes throughout the nation often have hairline cracks. The new foundation settles and dries, which causes them to form within a year. Good news! These cracks are often only cosmetic and may be fixed by homeowners doing it themselves for about $200 or by experts for $400-$600.

Get in touch with the builder if you see foundation cracks that are only hairline after you buy a house. Your warranty could cover the hairline crack. Document the crack and its evolution with images.

Shrinkage Crack

Foundation cracks caused by shrinkage seem like hairline fissures in wet-poured concrete when the foundation dries out. Types of foundation cracks caused by shrinking can appear in newly constructed homes during the first year. Most of the time, these fissures run vertically and won’t cause any major problems for your foundation. The danger becomes critical if radon gas seeps into your basement from a nearby place.

Inquire about the house warranty with the builder if you are a new home buyer. Foundations that have shrunk might be covered. In such a case, take a picture and record the crack. Consider getting an epoxy crack injection fix if it worsens or you find further cracks.

Vertical Cracks

If you see cracks running vertically rather than horizontally in your foundation wall, don’t worry—they won’t compromise the structure. They run vertically up and down your wall and are usually seen in poured foundations. Vertical cracks are one of the most common basement cracks in the USA. The sinking of the foundation over time or the natural curing process of concrete are the causes of these.

Epoxy or polyurethane crack injections are the go-to methods for fixing vertical cracks. Professional crack injections begin at $400, and do-it-yourself kits cost $75. Assuming the break is too small to accommodate a quarter, and there is no sign of moisture, there is no pressing concern. Epoxy injection allows you to photograph the crack or repair process in real time.

Foundation Crack That Is Not Structural Wet

When water evaporates from concrete, it causes the foundation to shrink, which in turn causes this sort of crack to form. It usually occurs during the first month after the pouring of a foundation. It is more likely that types of foundation cracks will appear if the concrete mix is originally wetter since shrinkage will occur more often. Cracks may also form as a result of the concrete’s natural settling.

We often utilize urethane as a sealing material for moist and aggressively leaking foundation cracks. When exposed to water, it’s a malleable material that expands to cover the crack after being easily injected into the hole.

Quick action is required in the event that water or moisture emanating from a crack is detected. The rapid shifts in the USA’s weather patterns pose a threat of more water damage or crack expansion.

Diagonal Cracks

Like vertical cracks, most foundation cracks that run diagonally do not cause significant structural damage. Curing or settling the concrete foundation wall may generate these, which can be seen running at a maximum of 30 degrees vertically. Epoxy crack injections are the most popular crack treatment method; professional crack repair services may cost $400 or more, while do-it-yourself kits cost $75.

Take a picture and note the date when you see a diagonal crack. You shouldn’t be concerned if the fissure is hardly noticeable and a quarter won’t fit. After six months, return to see whether the crack has persisted; if so, contact foundation crack specialists for advice.

Non-Structural Crack

In most cases, leaks caused by non-structural foundation cracks only occur when it rains, or the snow melts, and they do not compromise the home’s structural integrity. There may not be a structural risk, but water pouring into your basement is still cause for concern.

Damage to furniture, walls, and flooring, as well as mildew formation, may result from water seeping into a property. Also, these cracks might worsen if you ignore them. Any break in your basement, no matter how little, can eventually lead to water seeping into your house if you do nothing to fix it soon.

The natural curing process of concrete may cause tiny cosmetic cracks to appear on basement walls. The crack may not be structural if it is 1–2 mm wide and runs in a vertical or diagonal pattern.

Structural Crack

Because they might compromise your home’s structural integrity, these fissures are quite dangerous. Horizontal cracks or fissures bigger than 1/4 inch are signs of a structural weakness. Movement, whether due to changes in temperature, soil pressure, or shrinkage, is a common cause of structural foundation cracks.

Epoxy is the go-to substance for fixing the crack here. Epoxy is not usually sufficient to guarantee the healing of the crack since the stress that created it originally might remain as a consequence of movement. To prevent the crack from becoming worse, it is typically required to add further strength using carbon fiber straps or countersunk staples.

Quick action is required in the event that water or moisture emanating from a crack is detected. The rapid shifts in Ottawa’s weather patterns pose a threat of more water damage or crack expansion.

Bottom Line

Even for trained experts, assessing foundation cracks and other issues isn’t always easy. Some types of foundation cracks are minor and may be overlooked, while others need more resources. While this article does provide some broad recommendations, it is not meant to replace formal education and expertise in the field.

We advise contacting a structural engineer or other trained foundation crack specialists like at FoundationMD if you have concerns about your home’s foundation. Fixing foundation issues as soon as they become apparent is usually simpler and cheaper than waiting for them to worsen.

At FoundationMD, we are experts in all kinds of foundation issues and repairs. No matter what type of foundation cracks in your house, our professionals will come and assess the damage and guide you accordingly.