Sidewalk Crack Filler: Fix Walkway Cracks the Easy Way

The sidewalk in front of your house has a crack that's been there for ages. Grass grows out of it in June, it fills with grit every fall, and lately the edges look like they're breaking off. You don't need a contractor for that. A sidewalk crack filler and an hour of work usually handle it.

Sidewalks and garden walkways get foot traffic, rain, roots and, in colder places, ice and salt. For thin to medium cracks in a flat slab, a water activated concrete crack filler that goes in straight from the bottle is the simplest option. A few situations call for something else, and I'll point those out as we go.

The Short Answer

For narrow, stable cracks in a sidewalk or walkway, clean out dirt and roots, fill the crack with a ready-to-use concrete filler, level it, and keep foot traffic off until it cures. If one slab has lifted above the next and created a trip edge, filling won't fix it; the slab needs grinding, leveling or replacement. Also check who's responsible for the public sidewalk in front of your house before you work on it.

Why Sidewalks Crack

Sidewalks are thin slabs, often poured on soil that wasn't compacted perfectly. That makes them more sensitive than a thick driveway.

• Tree roots are the big one. They grow under the slab and lift it from below.
• Freeze-thaw opens existing cracks a little more each winter.
• Settling soil leaves a section unsupported, so it cracks and sinks.
• Shrinkage creates thin cracks early in the slab's life.
• Heavy loads like a car pulling onto the walk or a dumpster on the edge.

Fill It, Level It or Replace It?

Before you buy anything, look at both sides of the crack and the joints between slabs.

A filler is the right fix when

• The crack is narrow and both sides sit at the same height
• The slab feels solid underfoot and doesn't rock
• The crack hasn't grown noticeably in months

Something else is needed when

• One slab is higher than the next. That's a trip hazard. Grinding, leveling or replacing the slab is the fix.
• The slab is broken into several loose pieces.
• Roots are visibly lifting the slab. Filling won't stop a root from pushing.
• The crack keeps getting wider.

In many towns, the public sidewalk is the homeowner's responsibility; in others, the city handles repairs or has rules about who can do them. A quick call to your city or a look at its website before you start can save you trouble.

What to Look For in a Sidewalk Crack Filler

• Easy, precise application. Sidewalk cracks are long and thin, and a pointed applicator puts filler in the crack instead of all over the walk.
• Weather resistance. Once cured, it has to survive sun, rain and seasonal temperature swings.
• Works on the surfaces you have. Many walkways mix concrete with brick edging or stone steps, so a product suited to concrete, masonry, brick and stone covers all of it.
• No mixing. For a handful of cracks, skipping the bucket and trowel saves real time.

The Crack Repair Filler by VALYA is ready to use, water-activated, and suitable for concrete, asphalt, masonry, brick and stone. For general background on filler types, see our guide to choosing a concrete crack filler.

How to Fill a Sidewalk Crack

Choose a dry day, and put out a cone or a chair so nobody walks through your work.

1. Pull out weeds and grass by the roots. A weeding tool or a flathead screwdriver works well.
2. Scrape out dirt and loose concrete along the full length of the crack.
3. Wire-brush the edges until you see firm concrete on both sides.
4. Blow or vacuum out the dust. A leaf blower is the fastest tool for long sidewalk cracks.
5. Fill the crack by running the applicator tip slowly along it so the filler goes down in.
6. Level it flush with a putty knife, then sweep off anything left on the surface.
7. Mist lightly with water using a spray bottle.
8. Let it set, keeping foot traffic off until it's fully cured per the product directions.

Deeper cracks go in layers: fill partway, mist, let it set, then repeat. The same approach is used when filling large cracks in concrete that are deep but still stable.

Mistakes to Avoid

• Filling over roots and soil. Grass grows right back through a thin skin of filler.
• Trying to fix a trip edge with filler. A ramp of filler over a lifted slab wears out quickly and still trips people.
• Working before rain. Water washing over an uncured repair can ruin it.
• Leaving filler on the surface. Sweep and smooth before it sets, or you'll have stains along the crack.
• Ignoring the tree. If roots are the cause, an arborist or contractor can tell you about root barriers or slab replacement.

FAQ

Who is responsible for fixing the sidewalk in front of my house?

It depends on where you live. Some cities make homeowners responsible for maintenance, others handle repairs themselves. Check with your city before doing work on a public sidewalk.

Can I fill a sidewalk crack where one side is higher?

Filling won't remove the trip hazard. A raised edge usually needs grinding, slab leveling or replacement, often by a contractor.

How do I keep weeds from growing back in sidewalk cracks?

Remove the roots completely before filling, then fill the crack flush so there's no gap for soil and seeds to collect. A sealed crack gives weeds far less room to take hold.

Can I use the same filler on brick or stone edging?

If the product is suited to masonry, brick and stone, yes. The VALYA filler is. Make sure the brick or stone is solid before filling.

Wrapping Up

A good sidewalk crack filler makes a cracked, weedy walkway look tidy again in an afternoon. Clean out the roots, fill flush, and give it time to cure. Lifted slabs and root damage need a different fix, and public sidewalks may come with local rules.

If your walkway has stable, cosmetic cracks, take a look at the Crack Repair Filler by VALYA and see if it fits your project.