How to Keep Markings on Wet Concrete

Preparation

• 1

  Start with a properly prepared gravel bed-pathway, with nailed wooden form boards bordering it. As soon as you’ve poured in the wet concrete, drive a flat spade between the concrete and the inner edges of the form boards, to force the mass slightly away from the boards and create a slight space between them.

• 2

  “Strike” the concrete. With the unwarped wooden straight edge, push, compact and level the still-wet concrete, working your way from one edge to the other end. If portions of the concrete begin to pile up on one side of the straight edge as you work, lift the wood and push these back down. Finish the striking by zigzagging the plank from side to side, while keeping it straight on top of concrete surface.

• 3

  Smooth out the compacted concrete with the darby board. Work quickly. Press down lightly on the darby’s trailing edge as you sweep it back and forth across the surface, in wide arcs. Expect “bleed water” from the concrete to begin floating to the surface as you work. When this happens, wait until the water evaporates before you continue with the rest of the procedure.

• 4

  Smooth and compact it further with a wooden trowel when the water evaporates and the concrete’s surface begins to look dull. Keep the trowel pressed flat, and sweep it gently back and forth on the surface. If the concrete is too wide for you or your assistant to reach completely, you may use a secondary trowel or the “2-by-8” wooden plank-guide board to lean on. Move backward as you work, smoothing out any lean-marks or impressions you leave on the concrete.

• 5

  Use a small pointed trowel to cut away a top inch or so of concrete from its edges along the wooden form boards. Finish these edges by running an edger on them until they are smooth.

• 6

  Cut out “control joints” or expansion lines into the concrete every four feet or so. These are meant to allow for contraction and expansion of the finished concrete over time. First, place the guide board or plank completely across the concrete, resting it on the raised wooden form edges. Keep the guide board perfectly perpendicular to these 3/4-inch deep line across the width of the concrete. Run the tool back and forth this line to round out the cut.

Finishing

• 7

  Create line markings on its surface to give the concrete slab a nonskid, safety-tread surface. Decide how you want the lines run: straight horizontal or vertical or in curves.

• 8

  Draw the stiff-bristled broom across the concrete, pressing down slightly as you go, creating lines. Work quickly to create this finish before the concrete dries.

• 9

  Hose the broom clean with water before going back to work In case the broom lifts up small lumps of concrete.

• 10

  Cure the concrete once you’re done creating the marked finish. With a garden hose, very lightly spray the concrete with water to re-wet it. Cover the whole concrete with polyethylene sheets or burlap sacks, anchoring these to the ground with stones or bricks. Keep the concrete damp for about a week under these sheets. Curing the concrete this way allows it to dry and harden at the proper rate.

• 11

  Remove the cover sheets and form boards after the concrete has been cured and hardened.