A concrete patio doesn't fail overnight. It tells you what's coming for a year or two before it actually gets bad, and most homeowners miss the signs because concrete looks the same from a distance whether it's fine or falling apart underneath. Here in Shreveport we've got heavy clay soil that swells when it's wet and shrinks hard when it's dry, and that movement is behind most of what goes wrong with a patio slab. Knowing what to look for saves you from either panicking over a hairline crack or ignoring a problem until it's a full replacement instead of a patch.
Cracks: which ones are cosmetic and which ones aren't
Almost every poured slab gets a crack somewhere eventually. Concrete shrinks as it cures, and if the control joints weren't cut deep enough or spaced right (we cut ours every 8 to 10 feet, about a quarter of the slab depth), the crack shows up wherever it wants instead of where you planned. A hairline crack under about 1/8 inch wide, with both sides level to each other, is usually just cosmetic. Water can get into it and it'll widen slowly over the years, but it's not telling you the slab is failing.
What matters is a crack wider than 1/4 inch, or one where you can feel a lip between the two sides with your foot. That's not shrinkage anymore, that's movement. One side of the slab is settling or heaving while the other stays put, and that's usually the soil underneath doing something the original base prep didn't account for.
Uneven spots and standing water
Walk your patio after a hard rain. If water is sitting in puddles more than an hour or two after the storm passes, the slab has lost its pitch. Patios should slope away from the house at about 1/8 inch per foot, just enough to drain without you noticing the tilt when you're standing on it. When a section settles, that slope reverses in spots and water pools right where you'd put a chair.
That standing water isn't just annoying. It gets under the slab edges, softens the base material further, and speeds up whatever settling is already happening. It also freezes on the rare hard freeze nights we get, and that ice expansion works on any existing crack like a wedge. A patio that ponds water in October is usually worse by March.
Flaking, scaling, and that powdery surface
If the top layer of your patio is flaking off in flat chips, or the surface feels sandy and powders when you rub your shoe on it, that's scaling. It happens when the concrete's surface wasn't finished right to begin with, or when de-icing salt or the wrong sealer trapped moisture that had nowhere to go. It's a surface problem, not a structural one, but it only spreads. Once scaling starts on a patio it doesn't stop on its own, and pressure washing it just knocks loose material off faster.
This one's worth catching early because it's the cheapest to deal with. A section still sound underneath can sometimes be resurfaced with a bonded overlay instead of torn out, but that window closes once the scaling goes more than a half inch deep or exposes the aggregate underneath.
Sinking corners and gaps at the house
Look at the point where your patio meets the foundation of the house. A small gap here, maybe a quarter inch, is normal and even intentional; that's an expansion joint doing its job. What's not normal is a gap you can slide your fingers into, or a step down from the house threshold that wasn't there a couple years ago. That means the patio slab has settled away from the house while the foundation, on its own deeper footing, hasn't moved.
Corners are usually the first place this shows up because they have the least support from the rest of the slab. If a corner has dropped more than an inch below the rest of the patio, patching the surface won't fix it. The base underneath has washed out or compacted unevenly, and the fix is either mud-jacking to lift that section back into place or cutting it out and repouring with proper compacted base underneath, typically 4 inches of crushed stone under a 4-inch slab.
What can wait a season and what can't
Hairline cracks, minor color fading, and a little surface roughness from age can wait. Sealing every 2 to 3 years handles most of that cosmetic wear and slows down cracking you're already living with. What shouldn't wait is anything with a trip edge over about half an inch, active pooling that's getting worse each rain, or a crack that's grown wider than it was last summer. Waiting on those doesn't make them cheaper to fix later, it makes the base problem underneath worse and turns a patch into a full section replacement.
If you're not sure which category your patio falls into, get someone out to look at it before you decide. We do patio repair and full replacements around Shreveport and the surrounding towns, and half the calls we get turn out to be a straightforward resurfacing job rather than a tear-out once we've actually seen the slab and what's happening underneath it. You can see the rest of our concrete work at Infinite Concrete Solutions if you want to know what a repair or replacement actually involves before you call anyone.