Types of Basement Foundation Cracks

Having a crack in your basement is all too common. Different types of foundations have different types of basement foundation cracks. Most houses do develop cracks within a few years after they are built after they are built. It is a fact. While these cracks might seem non-threatening initially, they do have the potential to grow wider over time.

What is the difference between a structural crack and a settlement crack?

At a glance most horizontal cracks can be structural in nature, while most vertical cracks are not. This is not a hard and fast rule, just a starting point for most homeowners. If you have doubts and concerns, seek out the advice of a foundation contractor.

Types of basement foundation cracks  that can be defined as Structural:

  1. The crack will be in a load bearing foundation wall
  2. The crack will be below grade
  3. The crack will be in a stair-step pattern or horizontal

The soil outside the foundation wall exerts an enormous pressure on the foundation wall. Foundation walls are designed to be strong enough to resist this load. Your foundation wall should be acting as a retaining wall against the soil swell. A horizontal crack in a foundation wall is likely a sign that the foundation is failing under the weight of the surrounding soil.

A lot of pressure weighs down on your home from the entire weight of the house, and soil pressure from the earth. Occasionally additional loads exert pressure and the foundation begins to fail resulting in a horizontal crack in the foundation wall.

Types of basement foundation cracks  that can be defined as Non- Structural:

  1. The crack will be vertical
  2. The width of the crack will be small; typically 1/16″ to 1/8″
  3. The crack will not extend past the foundation into the structure

Nonstructural settlement cracks can be defined as having a small width typically 1/16” to 1/8” and not extending past the foundation into the structure. In masonry foundations such as CMU, cinder block or brick, settlement cracks typically run vertically or diagonally.

While a Non-Structural Crack is not threatening the integrity of the foundation, it is still a problem because it can be letting in water, moisture and/or soil gas. This is the type of crack that a DIY homeowner would fix themselves.