• Paul Kulzer

When to Worry About Foundation Cracks

Updated: Apr 26


Not All Cracks are Bad News

If you’re searching for “cracks in foundation when to worry,” you’re not alone. Many homeowners worry about foundation cracks. The good news is not all foundation cracks affect your home’s structural integrity.


Sometimes they’re just ugly and caused by shrinkage during the concrete curing process. These unsightly, non structural shrinkage cracks (which are often hairline cracks) don’t put your home in immediate danger. Structural cracks, on the other hand, are another story.


We’re going to cover both non-structural and structural cracks in this article. We’re also going to cover the causes of foundation cracks, foundation crack repair methods, signs of foundation problems, and more.


What Can Cause Cracks in Your Foundation?

Foundation cracks are caused by various things including (but not limited to),

  • Poor drainage around the foundation. Believe it or not, water is the cause of most foundation problems. Either too much or too little of it in the soil around your foundation is a recipe for trouble. Poor drainage around the foundation can cause hydrostatic pressure to build up in the ground and press against foundation walls. If the pressure isn’t relieved, the walls will eventually start to bow inward and even crack.

  • Weather changes. An example of this would be a house built during the dry season on top of expansive soil. When the rainy season arrives, the soil swells considerably, resulting in damage to the home’s foundation.

  • Soil that wasn’t adequately compacted before construction. If soil isn’t compacted before construction begins, the heavy structure built on top will sink into the ground unevenly. This causes foundation damage.

  • Expansive soil. This is soil with a lot of clay in it. It causes problems for construction because it swells a lot when it soaks up moisture and then shrinks by that same amount when it dries out. This creates soil movement, which can cause structural problems.

  • Soil creep. Homes built on slopes can, over time, develop foundation problems due to soil creep. This is when the soil at the top of a hill eventually makes its way down the hill. Soil creep can cause a foundation to move laterally.

  • Natural disasters. We probably don’t need to tell you that earthquakes, floods, and other natural disasters can cause foundation problems.

  • Heavy excavation next to the foundation. This cause of foundation problems isn’t obvious to most homeowners. Here’s a way to picture what happens: Imagine a beach chair sitting on the sand. If you start digging a hole too close to the chair, it will eventually fall into it. Something similar can happen when there’s heavy excavation next to a foundation. The home probably won’t fall into the hole, but the excavation can cause foundation problems.

Nature tends to cause foundation cracks because they all cause something called differential settlement.


Structural cracks in a foundation and when to worry

Structural cracks are caused by foundation movement and can, if they’re not promptly repaired, eventually threaten a building’s structural integrity. Non-structural cracks are caused by concrete shrinkage during the curing process and don’t threaten a building’s structural integrity. However, that doesn’t mean non-structural cracks are harmless.

When we talk about structural foundation cracks, we’re talking about cracks in poured concrete walls and concrete block foundation walls. We’re not talking about cracks in drywall or plaster. Cracks that are only in the drywall or plaster don’t threaten a building’s structural integrity. They’re just unsightly. Differential settlement is the cause of most structural foundation cracks.


When to Call a Professional You can start to worry when you see,

  • Cracks that are wider than 1/10 inch

  • Cracks that are wider at one end

  • Cracks that are getting bigger over time

  • Stair step cracks in brickwork

  • Horizontal foundation cracks, with or without bowing

  • Several vertical cracks near each other

  • Big, diagonal cracks

  • Cracks that go across the ceiling and down a wall

If you see any of the above, you should contact an experienced foundation repair contractor in your area for an inspection and repair estimate. Don’t delay. The longer you wait, the more expensive the repair will be!


Want to learn how we fix structural cracks or issues? Keep an eye out for next weeks blog post, "How to Fix Structural Foundation Cracks".

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