How to Install Expansion Joints in Sidewalks

Although concrete seems solid and unchanging, in reality it expands and contracts with changes in temperature. If a concrete structure like a sidewalk is to endure without cracking, it needs to be built to compensate for this effect. This is what the grooves in a sidewalk, known as expansion joints, are for. These spaces offer the sidewalk a little "give," allowing for expansion and contraction without damaging the concrete, so installing them is a necessary step for any sidewalk construction project.

Things You'll Need

• Lumber
• Tape measure
• Saw
• Groover
• Trowel

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Instructions

1. • 1

     Make a spacer by sawing down a piece of lumber to match the width of the concrete sidewalk.

   • 2

     Set the spacer across the width of the sidewalk so it can serve as a ruler of sorts, ensuring that you draw a straight line.

   • 3

     Draw the groover across the wet concrete of the sidewalk from one side to the other, using the spacer as a guide. Install an expansion joint in this fashion every 40 inches.

   • 4

     Cut control divets by pressing a trowel straight down into the expansion joint to a depth of roughly 1 inch. Install one divet into the expansion joint every 3 inches.