How to Lay Trench Mesh


Trench Mesh is a purpose-built reinforcing mesh for use in residential footing trenches and concrete beams. Correct preparation and technique are crucial to achieving optimum structural support from trench mesh.

This article will teach you:

  • The correct preparation techniques “pre-pour”.
  • How to cut steel to size using an angle grinder.
  • The correct tying technique to overlap steel.

Trench Mesh Tools You Will Need

Before beginning any job, get prepared. Gather the right tools at hand for a speedier and safer workflow and better results:

  • Angle grinder
  • Bolt cutters
  • Earmuffs
  • Gloves
  • Joining wire
  • Measuring tape
  • Safety glasses
  • Wire-cutter

Materials Required

Just as with your tools, get your materials prepared to save you time and keep you organized. There’s nothing more annoying than having to make a trip to the hardware store halfway through a job.

Materials Needed:

  • Reinforcing bar chairs
  • Trench mesh steel

Before You Begin

Working with concrete can take a bit of getting used to, so if it’s your first time, read through the following tips before you get started.

Tip 1: To allow your concrete to set correctly, don’t add all the water at once. You can always add more as you go.

Tip 2: If it’s a hot day, remember that concrete sets much faster in heat. You’ll need to work at a quicker pace to combat this.

How to Lay Trench Mesh Instructions

Step 1: Laying the reinforced steel

Lay a straight line of reinforced steel along the entire length of the trench. Then, divide the plastic bar-chairs into left and right pairs. Place them under the steel, at about 1-metre intervals, going the full extent of the trench to raise the steel off the bottom.

Step 2: Extending a line of reinforced steel in the trench

Very often, a trench will be longer than a single piece of steel. You can reach the entire length of the trench by overlapping the steel. Simply measure the shortfall and add 500mm to that length. Cut the next stretch of steel to the measurements, using your angle grinder. Place it in the trench and raise it with plastic bar-chairs as before. Where the steel lengths overlap, use joining wire to tie the sections together. Complete this process until the reinforcing steel runs the entire length of the trench. Once this is done, you’re ready to pour the concrete.

Using a Trench Mesh Spacer

A trench mesh spacer, trench mesh clip, or trench mesh chair as they are also known is a handy tool to save time and money and speed your workflow. Constructed from galvanized steel, trench mesh spacers instantly form a rigid cage for the foundation and footing beam. Place one end of the spacer on the centre of the mesh cross-wire. Clip it to the bottom bar. Place the top bar at the centre, and snap it into place with a firm grip. To learn more about trench mesh ligatures have a read of our useful guide.

L8TM200 Trench Mesh Concrete Slab