How to Renew Concrete Surfaces
Renewing a worn concrete surface can be done without a jackhammer or bulldozer
In the past, when a concrete patio or driveway started to show serious signs of aging, using a jackhammer or bringing in a bulldozer were the only repair options. Today there are more practical alternatives.
Polymer-based cement resurfacers are formulated to transform cracked, spalled, weatherworn concrete to like-new condition. The top dressing we used, Ardex All-Purpose Concrete Resurfacer, is made of portland cement and high-performance polymers. It's mixed with water and applied with a steel trowel, squeegee or push broom to a thickness of only 1/16 inch. One 20-lb. bag costs about $25 and covers 50 to 60 square feet. (The average concrete driveway is about 500 square feet.)
Besides patios and driveways, Ardex can be used to resurface concrete stairs, sidewalks, garage floors, and most vertical surfaces. For our project, we resurfaced a 9 X 27-foot driveway and 3 X 18-foot walkway using six bags of Ardex. It took two people five hours to complete the job. The work isn't particularly difficult, but the pace is frenetic. Once the water is mixed in, you've got less than 30 minutes to apply the concrete dressing.
For optimum results, work on a day with low humidity, no rain and an air temperature ranging between 70° and 75°F. The surface temperature of the existing concrete must be at least 50°F.
Fill the Cracks
Patch all cracks, crevices, and holes in the old concrete surface. For hairline cracks up to 1/8 inch wide, mix four parts of Ardex Concrete Dressing to one part water. Force the thick paste into the cracks with a putty knife. For larger cracks up to 1/2 inch wide, use concrete-repair caulk. Squeeze the caulk into the cracks with a caulking gun, and smooth it with a putty knife.