The newly available brush-on resurfacers restore a like-new appearance to walks, drives and patios. Often they're the only way to disguise a repaired concrete surface, such as porch steps.
Make any required repairs to large cracks, broken corners, steps or similar concrete damage (see How to Fix Cracked or Damaged Concrete).
Cut back any grass or plants along a walk or driveway you're resurfacing, and press foam backer rods into expansion joints so you won't end up filling them with resurfacer.
Pretreat stains, which can interfere with bonding, using muriatic acid. Dilute the acid in a plastic pail or spray bottle by adding 1 part of 20 percent acid to 4 parts water (see Warning). Carefully apply the acid solution to the affected areas using a brush or spray bottle. Allow it to work for a few minutes, then hose it off.
Wash surfaces from the center outward. Use a hose and nozzle or (better) a pressure washer, which you can rent.
Use a shop vacuum to clear loose material out of cracks. Don't blow it out or you'll contaminate the surfaces you just cleaned.
After you've gathered your tools, soak the surface with water and brush off any standing water.
Mix the resurfacer with water as directed, using a 1/2-inch (12-mm) drill with a paddle mixer.
Level depressions and fill small cracks. Allow these repairs to dry before coating the entire surface.
On horizontal surfaces, apply resurfacer with a trowel on small areas, such as stair treads, or with a wide squeegee on large areas, such as walks. For vertical surfaces, such as stair risers, mix the material with slightly more water and apply it with a plaster brush. Have containers of water available so you can quickly rinse off trowels and brooms between uses. Work in manageable sections. Proper application techniques take some practice, and the material sets up quickly (in about 20 minutes).
Finish and texture the material as you apply it. For a smooth surface, use a steel trowel in a circular pattern. For a slightly rougher texture, use a wood float, which you can make by putting a handle on a block of wood that has slightly rounded corners. For the very rough finish typical of sidewalks, draw a stiff broom or brush across the surface.