How to Finish Concrete
Timing and technique for screeding, floating, edging, troweling, and brooming concrete to achieve a durable, professional surface finish.
Step-by-Step
- 1
Screed immediately after placement
Strike off excess concrete with a screed board pulled across the forms in a sawing motion. Remove high spots and fill low spots. Screed to within 1/8 inch of final grade. Work quickly — the window narrows fast in warm weather.
- 2
Bull float the surface
Make 2–3 passes with a bull float immediately after screeding. Push the float away from you with the leading edge slightly raised; pull it back with the trailing edge slightly raised. This embeds aggregate, removes screed marks, and begins to close the surface.
- 3
Wait for bleed water to disappear
This is the most critical timing decision in concrete finishing. Do not touch the surface while bleed water is present — you will seal it in and create a delaminated surface layer. Wait until the sheen disappears and the surface has a uniform matte appearance.
- 4
Edge the perimeter
Run an edger along all form edges to create a rounded, chip-resistant border. Keep the edger nearly flat — pressing too hard creates a ridge that must be floated out.
- 5
Float the surface
Use a hand float or Fresno in a sweeping arc motion to smooth the surface and close any remaining voids. This pass densifies the surface and prepares it for troweling. The surface should feel firm but still workable.
- 6
Trowel for smooth finish (if required)
Make progressively tighter trowel passes as the concrete stiffens. First pass: open arc with low pressure. Subsequent passes: tighter arc with more pressure and a steeper blade angle. Interior slabs get 2–4 trowel passes; avoid over-troweling, which causes burn marks.
- 7
Broom for exterior texture
For driveways, sidewalks, and any exterior surface: drag a dampened broom across the surface perpendicular to traffic direction after the final float pass. Consistent pressure and speed give a uniform texture.
- 8
Apply curing compound
Apply curing compound in two passes at right angles to each other immediately after finishing. Do not allow the surface to dry out before compound is applied. On windy days, apply even faster.
Pro Tips
- → Experienced finishers read the concrete, not the clock. Check set progress by pressing your thumb into the surface — it should just leave an impression.
- → Start finishing at the edges first — they set faster than the center.
- → In hot weather: sunshade, windbreak, and ice in the mix water are your friends.
- → A magnesium float leaves a smoother surface than wood; a steel trowel leaves the smoothest.
Watch Out
- ! Finishing over bleed water is the #1 cause of concrete surface delamination.
- ! Over-troweling burns the surface and reduces durability — stop when the surface is flat and closed.
- ! Never sprinkle dry cement on the surface to absorb bleed water.