How to Tell If Your Concrete Cracks Need Professional Repair

Concrete cracks. It's not a sign of poor quality — it's a fact of the material. All concrete will develop some cracking over time, especially in the Houston area where expansive clay soils shift with every rain cycle. The real question isn't whether your concrete will crack, but whether the cracks you're seeing are normal or a warning sign that needs attention.

After years of repairing concrete across Katy and the Greater Houston area, we've learned to read cracks like a map. Here's how to evaluate what you're looking at.

Cosmetic Cracks — Monitor But Don't Panic

Hairline Cracks

Hairline cracks are very thin — typically less than 1/16 inch wide — and usually run in no particular pattern across the surface. These often form during the curing process as concrete shrinks slightly while drying. They're extremely common and in most cases don't compromise the structural integrity of the slab at all.

What to do: Monitor them over time. If they don't widen or lengthen over 6–12 months, they're cosmetic. You can fill them with a concrete crack filler to prevent water infiltration, which is good practice in Houston's wet climate.

Crazing

Crazing looks like a network of fine surface cracks that resemble a spider web or cracked eggshell. It's caused by the very top layer of concrete drying too quickly — often due to hot, windy conditions during the pour, or finishing the surface while there's still bleed water present. In the Texas summer heat, crazing is not uncommon.

What to do: Crazing is almost always cosmetic. It affects only the top 1/8 inch of the slab and doesn't impact strength. A concrete sealer can help the surface look better and slow any further deterioration.

Cracks That Need Attention

Cracks Wider Than 1/4 Inch

Once a crack reaches 1/4 inch in width, it's wide enough for water to flow into the subbase, for grass and weeds to take root, and for the crack edges to chip and spall. In the Katy area, water infiltration through wide cracks accelerates damage significantly — our heavy rainfall pushes water under the slab, softening the subbase and causing further settlement.

What to do: Get a professional assessment. Cracks this size often indicate subbase movement and may need to be routed out and filled with a flexible polyurethane sealant, or in worse cases, addressed with slab lifting or replacement.

Cracks Running the Full Width of a Slab

A crack that runs completely across a driveway panel, patio section, or walkway slab — from edge to edge — means the slab has essentially broken into two pieces. Even if the two halves are still flush with each other, the slab no longer functions as a single structural unit. Vehicle traffic, ground movement, and water will cause the two sides to shift independently over time.

What to do: This typically warrants professional repair or replacement of the affected panel. If one side has already begun to settle lower than the other, don't wait — the step created is a trip hazard and will only worsen.

Uneven or Heaved Cracks

If one side of a crack is higher than the other, the slab is experiencing differential settlement — the ground beneath is moving unevenly. In Houston's clay-heavy soil, this is one of the most common concrete problems we encounter. Root intrusion from nearby trees is another frequent cause.

What to do: This needs professional attention. Depending on severity, solutions range from grinding down the raised edge to slab lifting (mudjacking or polyurethane foam injection) to panel replacement. Left alone, the height difference creates a trip hazard and will continue to worsen with each rain cycle.

Cracks That Signal Serious Problems

Foundation Cracks

Cracks in or near your home's foundation slab deserve immediate professional evaluation. Horizontal cracks in foundation walls, diagonal cracks radiating from corners of windows and doors, or cracks that are wider at the top than the bottom can all indicate foundation movement that goes beyond normal concrete behavior.

What to do: Contact a professional right away. Foundation issues don't resolve themselves — they progress. Early intervention is significantly less expensive than waiting.

Multiple New Cracks Appearing Rapidly

If your driveway or patio develops several new cracks within a short period — especially after a wet season — it can indicate that the subbase has failed. This is more common in older concrete installed before improved subbase practices, or in areas with poor drainage.

What to do: Have a contractor evaluate the subbase condition. In some cases, the concrete can be repaired; in others, removal and reinstallation with a proper gravel base is the right long-term solution.

A Simple Rule of Thumb

When evaluating any concrete crack, ask yourself three questions:

• Is it growing? Mark the ends of the crack with a pencil and check back in 30 days. Growing cracks need attention.
• Is it uneven? Run your hand across the crack. If you feel a lip, it's a trip hazard and needs repair.
• Is it letting in water? Watch it during the next rain. If water flows into the crack, seal it at minimum.

If you're unsure about any crack on your property, the safest and most cost-effective step is a professional inspection. Contact Katy Concrete Co for a free assessment — we'll give you an honest evaluation and only recommend work that's actually needed.