Structural or Non-Structural - Understand Foundation Cracks

Cracks are a popular topic in the waterproofing industry, and when property owners notice them they could be worrisome. Because they lead to water damage and jeopardize the stability of the foundation, hire a professional to assess your cracks to determine if they are structural or non-structural. However, not all cracks cause structural damage.

Some cracks are just a natural sign of aging, but they should never be ignored. Since water follows the path of the least resistance, water can flow through these cracks creating a perfect habitat for mold, mildew and insects. Soil gases such as radon can also enter through cracks, polluting the air in your home.  

If you have concrete foundation cracks, they can  get worse over time. They can start off as non-structural, allowing water to enter through the crack. If left alone, the water eventually deteriorates the inside of the concrete causing cracks to widen. These cracks can easily be fixed by hiring a foundation repair specialist to apply concrete crack injections into the affected concrete. If water seeps through the crack, polyurethane can seal the leak. For moving cracks, a more rigid epoxy material is used to seal the concrete and hold the crack in place. 

Know the Difference Between Structural and Non-Structural Cracks

Non-structural Cracks: Non-structural cracks are caused by changes in the moisture content and thermal movement. They can occur anywhere in the foundation wall where there are openings in the wall. Non-structural cracks can also be caused by the following conditions:

• Creep
• Vegetation/Trees
• Shifting or moving foundations
• Settlement
• Hydrostatic pressure

Some characteristics of non-structural cracks include:

• 1 to 2mm wide hairline cracks
• Cracks at the corners of doors and windows
• Vertical to diagonal cracks
• Cracks on plaster
• Narrow, less than 1/8"

Structural Cracks: Structural cracks are due to poor construction sites, swollen soil, poor soil bearing or overloading. These cracks are usually accompanied by other signs of foundation issues such as sticking doors and windows, slanted doors, sloping floors and cracks in porches.  The common characteristics structural cracks include:

• Continuous horizontal cracks along walls
• Vertical cracks that are wider at the top or bottom
• Stair-step cracks
• Foundation wall cracks
• Cracks in beams, foundation slabs
• Angled cracks that form in the corners of walls with a horizontal crack in the center
• Cracks wider than 1/8"
• Cracks extending to the upper levels of the home

Structural Foundation Crack Solutions

To repair non-structural cracks, a foundation repair specialist can use a crack injection method with urethane. It is injected into the crack to permanently seal it and prevent further leaks.