Search guides

Fix a driveway that has cracks

We'll confirm the surface type, rule out heaving and settlement, then fill hairline cracks with sealant or wider cracks with backer rod and filler—or tell you when to call a pro.

Troubleshooting · Home maintenance
1–2 hours (plus cure time)
What you'll need
  • Concrete crack filler or asphalt crack filler (match your surface)
  • Backer rod (for cracks wider than 1/4 inch)
  • Wire brush, pressure washer, or shop vac
  • Caulk gun or pour spout
  • Putty knife (optional, for smoothing)
Step 1 of 7

Quick triage — pick your path

Get started

Choose the option that matches what you see. You can jump straight to that section.

Show full guide

Steps

Goal: Confirm the surface type and crack size, rule out structural issues, then fill or call a pro.

  • Inspect the driveway. Note whether it is concrete (gray, hard) or asphalt (black, slightly flexible). Check the crack width—hairline (1/4 inch or less) or wider.
  • Good: Crack visible—proceed to Check for heaving or settlement.
  • Bad: Driveway looks intact—you may have a different problem (potholes, stains).

Check for heaving or settlement

Goal: Rule out soil or foundation issues before patching.

  • Look for sections that are raised (heaving) or sunken (settlement). Run your hand across the crack—if one side is higher, the slab may be moving.
  • Cracks wider than 1/2 inch and growing, or tree roots lifting the surface, need a pro. If the surface is flat and the crack is stable, proceed.
  • Good: Crack is cosmetic and stable—proceed to Hairline path or Wider path.
  • Bad: Heaving, sinking, or wide growing crack—call a pro.

Hairline crack — filler only

Goal: Fill a narrow crack with sealant so it is sealed and stable.

  • Remove dirt, debris, weeds, and loose material. Use a wire brush, pressure washer, or shop vac. Let the crack dry 24 hours after washing.
  • Apply concrete crack filler (concrete) or asphalt crack filler (asphalt). Use a caulk gun or pour spout. Apply at a 45-degree angle, slightly overfilling. Smooth with a putty knife if needed.
  • Let cure per the product label (usually 24–48 hours). Drive over gently at first.
  • Good: The crack is filled and the repair holds—done.
  • Bad: Crack reopens—call a pro to assess.

Wider crack — backer rod and filler

Goal: Fill a wider crack with backer rod and sealant so it does not reopen.

  • Clean the crack. Push backer rod into the crack so it sits about 1/2 inch below the surface. Alternatively, fill the depth with playground sand.
  • Apply concrete or asphalt crack filler over the top. Overfill slightly and smooth. Let cure per the product label.
  • Good: The crack is filled and the repair holds—done.
  • Bad: Crack reopens—call a pro to assess.

When to get help

Call a concrete or paving professional if:

  • The slab is heaving or sinking.
  • Cracks are wider than 1/2 inch and growing.
  • Tree roots are lifting the surface.
  • You have filled the crack and it keeps reopening.

Confirm you have assessed the crack and surface before calling. For related fixes, see Fix a ceiling that has a crack or Fix a wall that has a crack.

Verification

  • The crack is filled and the surface is smooth.
  • The repair holds under light vehicle traffic after cure time.
  • The crack does not reopen (if it does, call a pro).
  • No heaving or sinking near the crack.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Note the surface type (concrete or asphalt) and crack width.
  2. Rule out structural Check for heaving, settlement, tree roots; call a pro if present.
  3. Hairline crack Clean, fill with concrete or asphalt crack filler.
  4. Wider crack Install backer rod or sand, then apply filler.
  5. Call a pro Heaving, sinking, or repeated failure—call a concrete or paving professional.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Surface type (concrete or asphalt)
  • Crack width and pattern
  • Whether the slab is heaving or sinking
  • Signs of tree roots or soil movement
  • Steps already tried

Are there cracks in the driveway?

Inspect the driveway. Note the surface type—concrete (gray, hard) or asphalt (black, flexible)—and the crack width.

Inspect the driveway. Yes: Crack visible—proceed to check for heaving or settlement. No: If the driveway looks intact, you may have a different problem (potholes, stains, spalling).

Yes No

You can change your answer later.

Is the slab heaving, sinking, or is the crack wider than 1/2 inch?

Heaving (raised sections), settlement (sunken areas), or wide growing cracks can indicate soil or foundation issues.

Check for raised or sunken sections. Run your hand across the crack. Yes: Call a concrete or paving pro. No: Crack is flat and stable—proceed to check crack width.

Yes No

You can change your answer later.

Is the crack hairline (1/4 inch or less) or wider?

Hairline cracks need filler only. Wider cracks need backer rod or sand before filler.

Measure or estimate the crack width. Hairline: Clean, apply concrete crack filler or asphalt crack filler directly. Wider: Install backer rod or sand, then apply filler. Good: Repair complete—done. Bad: Crack reopens—call a pro to assess.

Hairline Wider

You can change your answer later.

Fill hairline crack and let cure

Clean the crack. Apply concrete or asphalt crack filler (match your surface). Let cure per the product label. If the crack reopens, the cause may be structural—call a pro.

Done

Install backer rod and filler, let cure

Clean the crack. Push backer rod into the crack (or fill with sand). Apply concrete or asphalt crack filler over the top. Let cure. If the crack reopens, call a pro to assess.

Done

Call a concrete or paving pro

Call a concrete or paving professional if: the slab is heaving or sinking; cracks are wider than 1/2 inch and growing; tree roots are lifting the surface; or you have filled the crack and it keeps reopening. Confirm you have assessed the crack and surface before calling.

Done

Different problem

If the driveway looks intact, you may have a different problem—potholes, stains, or spalling. See the relevant guide.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why does a driveway crack?
Common causes: temperature changes (expansion and contraction), settling soil, tree roots, freeze-thaw cycles, or heavy vehicle traffic. Hairline cracks are often cosmetic. Wider cracks, heaving, or sinking can indicate soil or foundation issues.
Can I fix driveway cracks myself?
Yes. Hairline cracks in concrete or asphalt can be filled with crack filler or sealant. Wider cracks may need backer rod or sand before filling. If the slab is heaving, sinking, or the crack keeps reopening, call a concrete or paving professional.
When should I call a pro for driveway cracks?
Call a concrete or paving professional if: the slab is heaving or sinking; cracks are wider than 1/2 inch and growing; tree roots are lifting the surface; or you have filled the crack and it keeps reopening. Structural issues need professional assessment.

Rate this guide

Was this helpful?

Continue to