Foundation Cracks – What Causes Them?

Foundation cracks have a range of causes, such as the surrounding soil being unstable or poorly drained. A home’s foundation can also crack because of settling. Some cracks are indicators of serious problems with a building’s structural integrity, while others are minor and can be ignored safely. About 60 percent of American homes are built on soils that contain clay. Most of these homes will undergo some foundation damage.

If a home is constructed on soil with high clay content, it can move up to about 2 inches every season, which is one of the causes of cracks in foundations.

When to Take Foundation Cracks Seriously

A foundation crack’s seriousness depends on factors like where the cracks are located and the number of them. Their direction and width are also important. Foundation cracks are common, especially in older homes.

Framing problems are among the potential results of foundation cracks. A cracked foundation can cause problems with a home’s roof, as well as its windows and doors. Correcting the foundation problems and the issues it causes can be expensive.

Reasons for Cracked Foundations

Most US homes have poured concrete, concrete block, or brick foundations. Each of these types tends to crack because of movement or stress. Sources of that movement and stress include:

Clay Soils

Soils containing a lot of clay tend to expand and contract a lot so foundation cracks are likely to happen in areas with clayey soils

Roots

Tree roots can cause cracks but usually not because the roots push up against the foundation. Instead, what usually happens is that the roots dry the soil under the foundation, causing it to contract.

Settling

When foundations settle, they are likely to crack. This is especially so when the foundation settles unevenly, an issue sometimes called “differential settlement.”

Poor Drainage

If drainage around the foundation is an issue, this can be a cause of foundation cracks and damage.

Leaky Pipes

Leaks in water or sewer lines can cause foundation cracking if the water saturates the soil around the foundation. The longer the pipes have been leaking, the greater the foundation damage is likely to be.

Insufficiently Compacted Soil

If the footings were dug before properly compacting the soil, the foundation will fall slightly and may crack as a result. This happens because the soil is unable to support the house’s weight.

Poor Engineering

If the foundation has not been properly planned and installed for the weight of the structure that will be built on it, it may crack under the weight. For example, cracking may occur if a two-story home is built on a foundation designed to support the weight of a single story.

Frost Heaving

In cold climates, the foundation may crack because the ground below the foundation might freeze. The expanding soil pushes upward and cracks the foundation.

Cracks are not always serious. Usually, they won’t cause or contribute to any structural problems. That said, homeowners should consult a professional to determine the severity of their foundation cracks. A structural engineer will be able to evaluate the foundation and provide a solution to prevent worsening damage.