How to Lay Out Rebar for a Sidewalk

Measurements

• 1

  Measure the overall length of the sidewalk to be constructed. This becomes the slab length (SL). If you are splitting the sidewalk into sections, measure each section separately.

• 2

  Calculate the length of the rebar for each section. Rebar length (RL) is the slab length (SL) minus .5; this allows enough room to fit the rebar in the slab. Using an example of a 50 foot long section, the SL (50) minus the RL (.5) equates to a rebar length of 49.5 feet.

• 3

  Repeat the measurement and calculation process for each section of sidewalk. A stick of rebar will be needed for every 8-inch width of the sidewalk.

Laying Rebar

• 4

  Draw a sketch of the sidewalk on graph paper. Draw the rebar into the sketch to conform with the spacing of the measurements you calculated.

• 5

  Measure the rebar into sections to fit the sidewalk layout. Cut the rebar with a circular saw using a metal-cutting blade. Rebar is purchased in 20-foot sticks. Use #3 gauge rebar, which is 3/8 inch thick.

• 6

  Lay the rebar in the area where the sidewalk is going. Lay out the entire grid. Tie the pieces together with tie wire by looping the wire around the rods then twisting the ends together, similar to tying a loaf of bread. Set the rebar 15 inches from any side of the sidewalk.

Positioning Rebar

• 7

  Set rebar chairs underneath the rebar at each location where two bars intersect. The chairs suspend the rebar off of the ground so the concrete can surround the bars. You want the grid to be in the center of the concrete on all sides. This helps the concrete stick to the rebar grid from every direction and eliminates the potential for cracking.

• 8

  Place rebar chairs at the ends of the grid. Put the hooks at the ends facing downward to the ground.

• 9

  Pour the concrete slowly over the rebar. Use a rebar hook to lift sagging rebar sections until the concrete sets enough to hold the grid in place.