If you see cracks in your home’s foundation, they should be evaluated by a repairman as soon as possible. Some cracks are merely superficial, but others can be dangerous.

Cracks in your home’s foundation can occur naturally from settlement, and in many cases, small cracks do not indicate a larger problem. In other cases, however, cracks pose a significant problem. So how can you tell the difference?

Read on to learn more about this common problem and when you should see a professional.

What is a slab foundation?

Home builders use various types of support systems, depending on soil conditions and architectural styles. The most popular foundation today is the monolithic concrete slab.

A slab foundation is made up of a single layer of poured concrete several inches thick and thicker at the edges to form a foundation. It is further strengthened by metal rebar reinforcing rods. The slabs are normally poured over a bed of crushed gravel to provide adequate drainage. In many cases, electrical and plumbing lines are located within the slab itself.

This type of foundation works best in areas where the ground does not freeze, but can be adapted to fit other areas.

Warning signs of an indoor problem

Foundation settlement is likely to occur over time, and most cracks are not a cause for concern. However, some seemingly unrelated signs could indicate a problem. These include:

  • A door does not close or gets stuck

  • Cracks in the walls, especially over doors, windows, or where the walls and ceiling meet

  • Cracks in the vinyl or ceramic tile covering a concrete floor

  • Windows that once opened smoothly now get stuck or won’t close completely

Outdoor warning signs of a problem

Outside your home, look for stucco cracks or z-cracks in brick or block construction. A leaning chimney is a sure indication of a problem, as is the presence of moisture, mold or moss along visible cracks in the exterior slab or base of the walls.

In and around your garage, pay attention if the walls are moving away from the garage door or if the garage door does not open or close properly.

What could be the problem?

Concrete slab foundations are generally reliable because they resist movement and settlement.

But when the ground below expands and contracts, stress is placed on the concrete. This usually happens when the soil gets wet and then dries out, but it can also happen if the underlying soil was not properly compacted before construction.

The location of the cracks does not necessarily indicate where the problem is. The cracks act, in a sense, like hinges that provide movement to the slab as it shifts, much like fault lines in an earthquake. However, the ground could be sinking anywhere below the slab, not necessarily directly below the crack.

a professional opinion

The general rule of thumb is that any crack a quarter inch or less is probably not a problem, unless one side is higher than the other. Many homeowners prefer to play it safe and have an engineer or foundation repair company inspect cracks to determine if there is a larger problem.

In most cases, repairs will help prevent further structural damage to your home, as long as the problem is fixed in time.

Solutions for cracked slab foundations

Repairs to a cracked slab can be done in a number of ways, depending on the source and extent of the problem. In most cases, the contractor will install a system of steel piers to support the weight of the structure, relieving pressure on the slab and preventing further damage.

If you’ve noticed any of these problems in or around your home, don’t hesitate to take action. Contact a foundation repair professional today.