Understanding Basement Wall Cracks

3 May 2024
 Categories: , Blog


Basement wall cracks can be a source of concern for any homeowner. These cracks can vary in size and direction, hinting at different causes and levels of severity. While some cracks may be cosmetic, others can indicate deeper structural issues needing immediate attention. Understanding the nature of the cracks is the first step toward effective repair.

Causes and Types of Basement Wall Cracks


Cracks in basement walls are primarily caused by the settling of the house, hydrostatic pressure from groundwater, thermal movement, and sometimes poor construction. Over time, these factors can form cracks, allowing moisture to enter the basement.


  • Horizontal Cracks: Often considered the most serious, these often indicate pressure from soil outside the basement.
  • Vertical Cracks: Common in many homes, these are usually caused by the settling of the house and are not always a sign of structural issues.
  • Diagonal Cracks: These can occur due to differential settling of the foundation, which may require more attention than vertical cracks.

Step-by-Step Guide to Basement Wall Crack Repair

Preparing the Area

Remove any loose material with a brush and clean the area to ensure the sealant will adhere properly. For some repair methods, you may need to widen the crack slightly to make room for the repair material.

Choosing the Right Repair Method

  • Epoxy Injections: Ideal for cracks that are no longer moving. Epoxy forms a strong, waterproof seal.
  • Polyurethane Foam: If the crack is still active, polyurethane foam expands to fill in the crack and moves with the foundation.
  • Hydraulic Cement: Useful for patching cracks in masonry walls, especially in emergency water leak situations.

Application Process

Whether using epoxy, polyurethane foam, or hydraulic cement, it's crucial to follow the manufacturer's instructions for application. Carefully inject the chosen material into the crack, ensuring it's filled and sealed. After the filler has been applied, smooth out the surface to match the surrounding wall. After repairing the crack, consider waterproofing your basement walls to prevent future moisture penetration. This can be achieved through interior sealants, exterior waterproofing, or drainage improvements.

When to Seek Professional Help

While minor cracks can often be repaired by DIY enthusiasts, larger or more complex cracks may require professional assessment and repair. If you notice horizontal cracks, significant movement, or water leakage, it's best to consult with a structural engineer or foundation repair specialist to ensure the structural integrity of your home.

Repairing basement wall cracks promptly can save homeowners from future headaches and costly repairs, keeping the foundation strong and the basement dry for years to come. Reach out to a local service, such as Crackstoppers Foundation Repair & Waterproofing, to learn more.