Cracks are the most common reason homeowners panic about their foundation — and most of the time, the panic is unwarranted. The trick is knowing which cracks are cosmetic and which are telling you the structure is moving.
Cracks that are usually cosmetic
Thin, vertical hairline cracks — especially in poured concrete within the first year or two as it cures and shrinks — are typically harmless. So are fine cracks in surface plaster or paint. They're worth sealing to keep water out, but they rarely signal structural trouble.
A crack you can barely fit a coin into, running straight up and down, is usually a maintenance item — not an emergency.
Structural warning signs
Get a licensed structural engineer to look if you see any of these:
What to do next
If you see structural signs, don't start with a contractor — start with a licensed structural engineer. For about $350–$1,000 they'll diagnose the cause and specify the fix, which stops contractors from overselling. Then price the repair with the cost calculator and, if a sudden event like a burst pipe was involved, check coverage with the insurance verdict tool.
Cost ranges here follow national aggregator data (Angi, Bob Vila, NerdWallet). See our methodology for how we calibrate.