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FAQs: Why Does Concrete Crack?

 

FAQs: Why Does Concrete Crack?

One of the most common questions we hear at RLW Concrete LLC is:
“Why does concrete crack?”

The short answer? All concrete cracks.
The important part is why it cracks and how it’s managed.

Let’s break it down 👇

❓ Is cracking normal in concrete?

Yes. Concrete is extremely strong, but it is not flexible. As it cures, settles, and reacts to its environment, some cracking is completely normal and expected.

❓ What causes concrete to crack?

1. Shrinkage During Curing

As concrete dries and hardens, water evaporates. This causes the concrete to shrink slightly, which can lead to surface cracking. This is the most common cause and usually cosmetic.

2. Temperature Changes

Concrete expands when it’s hot and contracts when it’s cold. In Pennsylvania’s freeze–thaw climate, this constant movement puts stress on the slab, which can cause cracking over time.

3. Ground Movement or Settling

If the soil beneath the concrete shifts, settles, or wasn’t properly compacted, the concrete above it can crack. This is why proper base preparation is critical.

4. Lack of Control Joints

Control joints are planned cut lines that allow concrete to crack in a controlled, straight line rather than randomly. Without them, concrete will still crack — just not where you want it to.

5. Heavy Loads or Pressure

Concrete is strong, but excessive weight or pressure beyond its design limits can cause cracking, especially in driveways or commercial areas.

❓ Can cracking be prevented?

Cracking can’t be completely prevented — but it can be controlled and minimized.

At RLW Concrete LLC, we focus on:
✔️ Proper site prep and base compaction
✔️ Correct concrete mix design
✔️ Strategic placement of control joints
✔️ Professional finishing techniques

❓ Does sealing help prevent cracking?

Sealing doesn’t stop structural cracks, but it helps protect the surface.

Using a concrete densifier and sealer like DensiCrete can:

  • Reduce moisture penetration

  • Strengthen the surface

  • Minimize surface wear and freeze–thaw damage

  • Extend the life and appearance of your concrete

Sealing is especially important in harsh weather environments.

❓ When should I be concerned about cracks?

You should contact a professional if you notice:

  • Cracks that are widening over time

  • Uneven or lifting slabs

  • Cracks accompanied by sinking or drainage issues

Not all cracks are a problem — but knowing the difference matters.

Final Thoughts

Concrete cracking is normal, but quality workmanship makes all the difference. Proper installation, joint placement, and long-term protection help ensure your concrete performs and looks great for years to come.

If you have questions about cracking, repairs, or sealing, RLW Concrete LLC is always happy to help.

📞 Call or text 814-290-7221
📍 Serving Clearfield, Centre, Blair & surrounding counties

⚠️ Legal Disclaimer:
This blog post is intended for informational purposes only and should not be taken as professional, legal, or construction advice. Every project is unique, and conditions may vary. RLW Concrete LLC is not liable for any actions taken based on this information. Always consult with a qualified professional or attorney for your specific needs.
License #PA65009




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