Thin cracks along a concrete foundation could be the result of settlement in the concrete and may not necessarily be a cause for concern, says Kathleen Kuhn, president of HouseMaster Home Inspections in Bound Brook, N.J.
However, homeowners need to pay attention to the shape and direction of the divide. Long, horizontal splits in the concrete could indicate pressure from the outside -- possibly from saturated soil -- that needs to be repaired.
"Normal settlement doesn't generally cause horizontal cracks," says Kuhn.
Regardless of shape, any cracks that leak water or are wider than one-fourth of an inch (some experts put the limit at one-sixteenth of an inch) should be inspected by a structural engineer immediately, says Kuhn.
Even if a crack appears to be minor, it should be repaired, Marston says.
"If moisture gets inside a small crack, it can cause the steel inside to rust, which could cause further deterioration," he says.
COST: According to Marston, the cost for a structural engineer to assess a property is about $300. If the expert finds major structural damage, the repair would be costly.
"Typical bills range from $10,000 to $30,000," he says.