Vertical Cracks in a Foundation

Characteristics

• Horizontal foundation cracks are a red flag that pressure outside your home may be pushing inward, a serious cause for concern. Conversely, small vertical cracks are common and usually don’t cause serious problems to your home’s structure or integrity. Vertical cracks with a width narrower than 1/4 inch are not usually regarded as threatening, unless there is significant displacement, according to the International Association of Certified Home Inspectors. Vertical cracks wider than this, especially if they are numerous or accompanied by horizontal cracks and foundation displacement, may require extensive repairs to mitigate the underlying problem.

Causes

• Normal settling and concrete shrinkage are among the most common causes of vertical foundation cracks. These types of cracks usually occur when your home is still relatively new. Other possible causes of cracking include improper drainage, adverse soil conditions and seismic activity. Substandard concrete mixtures may also result in vertical cracking within your foundation walls.

Prevention

• Proper soil compaction prior to pouring the foundation plays a major role in preventing or minimizing vertical cracking. The grade and slope of your surrounding soil also affects your risk of foundation cracking. Drainage systems around the foundation, especially for homes located along slopes or in low areas, can also help prevent these types of foundation cracks. Matching the concrete strength of the foundation walls to the strength of the footers also helps ensure the creation of a strong, sturdy foundation.

Repairs

• Unless you are skilled in concrete construction, home repairs that involve large foundation cracks are best left to professional contractors. Keep an eye on any crack that appears wider than the thickness of your fingernail. Consult a professional if you notice a crack that seems to be growing wider or if you have numerous cracks along your foundation walls. Depending on the underlying cause of cracking, your contractor may need to simply patch the cracks, install a drainage system around the outside of your foundation or possibly replace large sections of your foundation.