Reading Your Own Pavement: What Your Cracks Are Actually Telling You

Most property owners don't think about their pavement until something about it starts to bother them, and by then there's usually more than one kind of damage happening at once. Being able to tell the different types apart is useful, because they don't all mean the same thing, and they don't all call for the same fix.

Alligator Cracking

This is the pattern that looks like a web of interconnected cracks, often in a roughly hexagonal shape, resembling reptile skin, which is where the name comes from. Alligator cracking almost always means the base underneath has lost structural support, either because it wasn't compacted properly to begin with, because water has gotten in underneath it, or because the load on that section has exceeded what the base was built to carry. This is not a surface problem, and sealcoating or a thin overlay won't fix it. The affected section generally needs to be cut out, the base rebuilt, and the area repaved. Left alone, alligator cracking spreads and deepens, and water working its way into the cracks accelerates the process, especially with the wet-dry cycle we get here.

Raveling

Raveling is when the surface of the asphalt starts losing its aggregate, meaning small stones separate from the binder and the surface takes on a rough, pebbly, worn look, sometimes leaving loose gravel sitting on top. It's usually caused by aged binder that's lost its flexibility and adhesion, often from UV oxidation, sometimes from asphalt that was mixed or compacted incorrectly at installation. Raveling on its own is a surface issue rather than a structural one, and if it's caught early, a sealcoat can sometimes slow it further. Left unaddressed for years, though, raveling opens the surface up to water penetration, which can eventually lead to the base problems described above.

Potholes

A pothole is what happens when water gets into a weak spot, usually one that started as a crack, and repeated wet-dry cycling combined with traffic loading breaks the surface apart and pushes material out. Potholes tend to grow fast once they start, because the exposed edges keep letting more water in and traffic keeps knocking loose material free. A pothole is a base and drainage problem showing up at the surface, not just a surface defect, and patching it properly means removing the damaged material down past where the water got in, not just filling the visible hole.

Birdbaths

A birdbath is a low spot in otherwise flat pavement where water collects and sits after rain instead of draining away, named for the fact that it genuinely will hold standing water like a shallow dish. Birdbaths usually come from a section of base that settled slightly after the surface was already laid, or from a grading mistake at installation that left a section without enough slope. They're deceptively low-drama to look at, sometimes just water sitting in a shallow dip, but they're one of the most damaging things a pavement surface can have, because standing water sits and works into the surface for hours or days rather than running off in minutes. A birdbath that gets ignored is very often where a pothole shows up next.

What Actually Needs a Phone Call

• Alligator cracking anywhere on the surface, regardless of size.
• Any spot where water stands for more than an hour or two after rain.
• Potholes of any size, since they only get bigger.
• Raveling that's progressed to the point of loose gravel sitting on the surface.

Fine surface cracking without any of the above is generally normal aging and worth keeping an eye on rather than panicking over. The patterns above are the ones that actually predict what's coming next, and catching them early is almost always cheaper than waiting for them to turn into a full section replacement. If you're looking at your driveway or lot and aren't sure which of these you're dealing with, send us a photo or have us come take a look in person. Estimates are free, and there's no obligation attached. Call (512) 756-3094.