Quick Answer: What Causes Cracks In Concrete Driveway?

Are cracks in concrete driveway normal?

In theory, concrete that is formulated correctly for its use and placed on a well compacted, well engineered base, and finished perfectly, should never crack. But that rarely happens. So concrete usually cracks. That fact is the reason concrete contractors put “control” joints in large slabs of the material.

How do I keep my concrete driveway from cracking?

If you’re having new concrete poured consider the following ways to prevent cracking:

  1. Start with a sound subgrade. Make sure the subgrade is compacted.
  2. Modify the concrete mix. Use a low water-to-cement ratio.
  3. Install joints. Be active in deciding where control joints will be placed.
  4. Properly cure the concrete.

When should I be concerned about cracks in concrete?

A crack in a slab of 1/8 inch or less is typically a normal shrinkage crack and not a cause for concern. If the crack is larger or growing larger (an “active” crack), or one side of the crack is higher than the other, then you may need to have the work reviewed by a structural engineer.

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Can you pour new concrete over old cracked concrete?

There are situations when pouring new concrete isn’t the most suitable option. For instance, surfaces with larger cracks, heaving or settling conditions, or where height cannot be raised, replacement is a better solution. However, in most cases, you can pour a new layer of concrete onto the existing one.

How much does it cost to fix a cracked driveway?

Most contractors charge an average of $2.00 to $2.50 per square foot to apply a filler and sealant to the damaged area. For a 250 square foot repair, you can expect to pay around $500 to $625 for the concrete driveway crack filler application and acrylic sealant.

How long should a concrete driveway last?

A concrete driveway should last a minimum of 20 years, but a full replacement is necessary when cracks and pits are interconnected. If your foundation is lifting or there are numerous potholes across the surface of the concrete leading to drainage issues, it’s time to replace the driveway.

How thick does concrete need to be to not crack?

Applied-load cracking.



In residential concrete, 4 inches is the minimum thickness for walkways and patios. Garage slabs and driveways should be 5 to 6 inches thick if any heavy truck traffic is anticipated, otherwise 4 inches is adequate.

How do you fix a small crack in a concrete driveway?

You can repair hairline cracks in concrete with a grout made of Portland cement and water. Add just enough water to the cement to form a thick paste. Moisten the old concrete along the hairline crack with water for several hours before adding the grout.

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How much should a concrete driveway cost?

A concrete driveway costs from $8 to $18 per square foot, depending on decorative colors and finishes. While a plain gray concrete driveway costs between $5 and $7 per square foot to install. Concrete is ideal for getting the look of stone or pavers, without the high cost.

How can you tell if a crack is structural?

Telltale signs of structural cracks in your foundation are:

  1. Stair-step cracks.
  2. Cracks on foundation slabs or beams.
  3. Vertical cracks that are wide at the bottom or top.
  4. Cracks measuring 1/8″ in width.

How do I know if my foundation crack is serious?

While you’re under your house in a basement or crawlspace, you’re looking for any cracks or signs of damage. If you find long horizontal cracks, leaning, or bowing walls, you are in dangerous territory. If the foundation walls are made of concrete block, the cracks may look like stair-steps.

How bad is a cracked foundation?

Settling soil creates additional pressure on a foundation wall and can lead to cracking. Vertical cracks often admit significant amounts of water and must be repaired. Horizontal Cracks: Horizontal cracks are a serious issue that usually indicate heavy soil pressure.

Can you put a thin layer of concrete over concrete?

Yes, you may pour a concrete pad overlay over an existing slab. You need to consider the added height and weight of the overlay on the existing structure. Overlays may include polymers, portland cement concrete, or epoxies.

What can I put over cracked concrete?

Lastly, the most popular way to patch up cracks formed in concrete is with polymer resin. This option is the most expensive DIY option as it not only fills the entire depth of the break but also forms a permanent chemical bond with the concrete slab, gluing the slabs together to seal it from any structural moisture.

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Does concrete adhere to old concrete?

The cement within a concrete mix doesn’t contain any natural bonding agents – so when fresh concrete is added on top of an existing layer of concrete, the two won’t join together. Once cured, the new concrete will simply sit on top as a separate layer. This will not produce a strong, serviceable floor.

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