man trowels concrete resurfacer onto a concrete walkway

How to Resurface Worn Concrete

Trowel concrete resurfacer over your worn walkway, and you'll have a brand new, durable surface with uniform color

Q: Our concrete walk has pits and seems to be crumbling. How can we fix it?
—Jace Laakso, Missoula, Mont.

Tom Silva replies: Spalling, the pits that form in concrete, happen when too much water is used in a concrete mix, weakening it.

As long as your walkway isn't cracked all the way through, you can coat the slab with a concrete resurfacer, a no-shrink blend of Portland cement, sand, and polymer additives that fills divots and makes a uniform finish. Its natural color is dark gray, so buy enough to cover your entire walk. One 40-pound bag coats about 35 square feet. If you want a different color, just add a concrete tint.

Before resurfacing, strip off any paint or sealers and watch the weather. Temperatures should remain above 50 degrees F for 8 hours after the pour and above freezing for 24 hours after that.

Resurfacing takes most of a day, but your walkway will be back in pristine shape once you're done.


Steps // How to Resurface Worn Concrete
1 ×

Clean the Concrete

 
Step One // How to Resurface Worn Concrete

Clean the Concrete

pressure-washing the concrete walkway to prepare for resurfacing
Photo by Ryan Benyi

While wearing heavy boots and protective glasses, blast off surface dirt with a gas-powered pressure washer that can reach at least 3,500 psi. Fit the wand with a 25-degree fan tip, and hold it 6 to 8 inches from the surface as you clean the concrete with slow, even sweeps. To remove mildew or algae, use a concrete wash.

 
2 ×

Patch Spalled Areas

 
Step Two // How to Resurface Worn Concrete

Patch Spalled Areas

patching the concrete walkway to fill in the spalling before resurfacing
Photo by Ryan Benyi

While the concrete is damp, mix up enough resurfacer to fill any divots. Combine 1 part water with 7 parts resurfacer in a 5-gallon bucket; blend with a paddle mixer attached to a corded drill. Fill the recesses with resurfacer, and smooth with a finish trowel. Go to the next step when you can stand on the patch without indenting it, in about 2 to 5 hours.

 
3 ×

Spread the Resurfacer

 
Step Three // How to Resurface Worn Concrete

Spread the Resurfacer

pouring the resurfacer onto the concrete walkway with a 5-gallon bucket
Photo by Ryan Benyi

Fill the walkway joints with peel-and-stick foam weatherstripping, and dampen the concrete if necessary. The resurfacer is workable for about 20 minutes, so mix just half a bag of powder with 5½ cups of water at a time. That's enough to cover two sidewalk slabs, or about 17 square feet. Pour it on the walk.

 
4 ×

Trowel It Out

 
Step Four // How to Resurface Worn Concrete

Trowel It Out

trowelling the concrete resurfacer on the walkway in order to spread evenly
Photo by Ryan Benyi

Spread the resurfacer until it's between 1/8 and ¼ inch thick. For a slip-resistant finish, wait 5 minutes, then sweep a nylon-bristle broom across it, 90 degrees to the foot traffic. Remove the weatherstripping after 20 minutes. Wait 6 hours before walking on it. Cover only if rain threatens in the meantime.

 
 
 

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