Foundations are the often overlooked yet vital components of our homes, offices, and commercial buildings. However, concealed beneath the surface, foundation cracks can appear without warning. Some cracks are superficial, affecting your home’s aesthetic appeal. Other types of cracks forewarn structural concerns that mandate more serious measures.
At HD Foundations, our team of certified professionals can help you identify which cracks cause concern and which are only cosmetic. In this guide, we’ll cover the different types of foundation cracks to look out for.
Structural and Non-Structural Cracks
There are different types of foundation cracks; understanding their differences is crucial.
- Structural Cracks: These are the ones that homeowners should be most concerned about. These cracks affect the foundation’s stability and may result from issues like foundation settlement or excessive lateral pressure. Cracks of this type demand immediate professional attention to prevent further structural damage.
- Non-Structural Cracks: On the other hand, non-structural cracks, often cosmetic, are typically less worrisome. While they can still be unsightly and allow moisture intrusion, these types of foundation cracks usually don’t pose a direct threat to the structural integrity of the building. These cracks can be addressed less urgently, focusing on cosmetic repairs and sealing to safeguard against water infiltration.
Knowing the difference between these two types of cracks empowers homeowners to take the right action at the right time, ensuring the longevity and safety of their homes. The following describes the different structural and non-structural cracks in any home.
Horizontal Crack
Horizontal cracks in a foundation are typically a cause for concern, as they often indicate serious structural issues. These cracks can result from excessive lateral pressure against the foundation walls, usually due to poor soil drainage or excessive soil saturation. They are particularly problematic because they can weaken the wall’s integrity and potentially lead to structural failure if not addressed promptly.
This type of crack can also be caused by hydrostatic water pressure or unbalanced soil. Poured and blocked foundations can be prone to this type of crack, showing signs of inward bowing and water leakages due to pressure against the foundation wall.
Repairing horizontal cracks involves reinforcing the foundation with steel beams and carbon fiber straps or a process called wall anchoring. This reinforcement helps stabilize the foundation and prevents further movement.
Vertical Cracks
Vertical cracks in a foundation are relatively common and often not as alarming as horizontal cracks. These cracks typically form when a foundation settles or shrinks during curing. While vertical cracks can allow some moisture intrusion, they are usually less severe and easier to manage than horizontal or diagonal cracks.
Vertical cracks can usually be found in poured foundations. You can find them running up and down walls. They are generally not structurally severe and can be repaired with epoxy or polyurethane injections to prevent water intrusion.
Stair Step Cracks
Stair step cracks are common foundation cracks in masonry or concrete block walls, which can appear along mortar joints. The two leading causes of this crack are moisture problems and foundation sinking or settlement.
These cracks resemble stairs, with each section offset from the next. They usually occur due to settlement or shifting of the foundation, which can be due to factors like soil movement or inadequate foundation construction. Addressing the underlying issue is crucial to prevent further damage to the structure.
Repairing stair step cracks may involve tuckpointing, which is removing and replacing damaged mortar joints and addressing the underlying foundation issues. It’s essential to fix the foundation problems to prevent the recurrence of these cracks.
Diagonal Cracks
Most diagonal cracks are like vertical cracks, which shouldn’t be a cause for concern since the natural curing of concrete foundations can cause them. These types of cracks usually run at a 30-degree angle and can be easily repaired.
However, diagonal cracks can be more concerning than the usual vertical cracks, as they often indicate structural stress or movement. These cracks typically appear at a 45-degree angle and can result from soil pressure, foundation settlement, or excessive moisture.
In any case, if you see diagonal cracks on your walls and foundation, they should be evaluated by a professional to determine their cause and the extent of the damage.
Repairing severe diagonal cracks involves underpinning the foundation with helical or push piers. This approach helps to stabilize the structure and prevent further cracking.
Hairline Cracks
Hairline cracks are thin, fine, and often less than 1/16 inch wide. While they may not initially seem serious, they can still be a concern, especially if they appear in large numbers or multiply over time.
They are common and can appear in any county or city regardless of climate or soil conditions. In addition, they often occur within a year of a new construction after the foundation has settled and dried.
Hairline cracks can result from minor settling or natural concrete curing and are usually not structurally compromising. However, they can serve as entry points for moisture, leading to more significant problems like water infiltration and further cracks. They are generally not a cause for concern and can be sealed with epoxy or polyurethane injection to prevent moisture infiltration.
Shrinkage Cracks
Just like hairline cracks, shrinkage cracks are common in concrete foundations and are typically not a sign of severe structural issues. Newly built homes are often prone to this type of crack within the first year of construction.
These cracks develop as concrete cures and contracts, and they are often small and straightforward to repair. While they may not be a significant concern, addressing them as early as possible can prevent further moisture intrusion or the widening of cracks. These are typically not structurally significant and can be sealed with epoxy or other sealants.
Foundation Slab Cracks
Slab cracks occur in the concrete foundation slab and can be caused by various factors, including soil settlement, temperature fluctuations, or improper curing. Slab cracks may not necessarily indicate severe structural issues but should be addressed to prevent moisture infiltration and further damage.
Here are the most common causes of foundation slab cracks:
- Frost Heave: During a frost, the water forming underneath a slab freezes, which causes the concrete to buckle. This effect is more common in crawl space slab foundations.
- Slab Settlement: Slab settlement issues are often due to poor workmanship. This means the ground underneath a slab foundation wasn’t appropriately compacted, or soil conditions weren’t addressed.
- Concrete Curing: This is a widespread cause of slab cracks, which is caused by the natural settling, drying, and curing of concrete. Cracks caused by curing are usually cosmetic and do not impact the structural stability of your building or home.
Professional repair of foundational slab cracks may involve slab jacking, where grout or a specialized foam is injected beneath the slab to level it.
Non-Structural Foundation Crack
Non-structural cracks often start as dry cracks and are typically surface-level cracks that don’t compromise the foundation’s structural integrity. These cracks can be cosmetic or caused by minor settlement, temperature changes, or the natural curing of concrete.
However, they can progress into a wet foundation crack that can cause leaks and moisture buildup after a storm or when the snow melts. While they may not significantly threaten the building’s stability, addressing them is essential to prevent further damage and maintain the foundation’s appearance, especially if the water is already seeping into your basement.
When water leaks into your home, it can cause several issues, such as mold growth and damage to your supplies, materials, and furniture. If left unattended, these cracks can worsen, which will be more costly to repair. Non-structural foundation cracks can be easily sealed with various sealants or epoxy.
Wet Non-Structural Cracks
As mentioned earlier, wet non-structural cracks are non-structural cracks with the added issue of moisture infiltration. These cracks typically form around a month after the foundation is poured.
While they may not compromise the foundation’s stability, they can still lead to problems like mold growth, wood rot, or other water-related damage if addressed. Managing moisture and repairing these cracks is crucial to maintain a healthy indoor environment. It can be sealed with waterproof sealants such as urethane or epoxy to prevent water damage. These flexible solutions can be into the crack to fill the inner cavity.
Structural Foundation Cracks
Structural foundation cracks are the most concerning cracks and damage, as they indicate a potential threat to the building’s stability. These cracks are often broader and longer and can appear in horizontal, vertical, or diagonal patterns. The causes of structural cracks are numerous, ranging from soil movement to inadequate foundation design. It’s imperative to consult a structural engineer to assess the severity of the crack and implement appropriate repairs to prevent further damage to the building’s structure.
Repair methods vary depending on the severity but often include underpinning with piers, wall anchoring, or rebuilding portions of the foundation wall to restore its structural integrity. A professional assessment determines the appropriate repair approach for structural cracks.
Work with Texas Foundation Specialists
For peace of mind and expert guidance in dealing with all types of foundation issues, look no further than Texas foundation specialists from HD Foundations. As a trusted authority in Dallas, Fort Worth, Frisco, and neighboring areas, our team combines years of experience with a commitment to delivering top-tier service.
We are dedicated professionals well-versed in addressing structural and non-structural foundation cracks, ensuring your home remains secure and resilient. When it comes to preserving the very foundation of your home, count on HD Foundations to provide the expertise and solutions you can depend on. Contact us to get a quote and have your questions answered.