How to Measure for a Glass Balustrade

This step-by-step measuring guide explains how to set out the centre line, measure the run correctly, account for overhangs and allow for tolerances before ordering a glass balustrade system.

Tools Required

Before measuring for a glass balustrade, make sure you have the correct tools ready.

  • Measuring tape
  • Pencil or marker
  • Straight edge or chalk line
Tools required to measure for a glass balustrade

Step 1: Set back from the edge

All centre lines should be set back 75mm from the substrate edge. This creates a consistent fixing line for channels or post fixings.

  1. Measure 75mm in from the edge of the substrate.
  2. Mark the centre line clearly.
  3. Keep the same offset along the full length of the run.
Setting the centre line 75mm back from the edge for a glass balustrade

Step 2: Measure the run

Measure the full run accurately and mark the centre line for each section. This will guide the position of your bottom channel and post fixings.

  1. Use a measuring tape to record the full run length.
  2. Mark each straight section clearly.
  3. Repeat the process for each additional run if the layout changes direction.
Measuring the run for a glass balustrade installation

Step 3: Account for overhangs

If the substrate has an overhang, measure at least 75mm perpendicular from the point where the overhang begins. This helps ensure the fixing line lands in a solid substrate suitable for bolt fixings.

  1. Identify where the overhang starts.
  2. Measure inward to a solid fixing zone.
  3. Confirm the intended fixing line remains structurally suitable.
Accounting for overhangs when measuring for a glass balustrade

Step 4: Allow for tolerance

Leave a 25mm gap from the end of the channel or end post to the end of the measured run. This provides adjustment tolerance and allows proper water run-off.

  1. Measure the full run.
  2. Allow 25mm clearance at the end position.
  3. Confirm the final measurement before ordering materials.
Allowing for tolerance in glass balustrade measurements

Final Check Before Ordering

Before drilling or fixing, make sure all measurements are accurate and the fixing area is suitable.

  • Recheck all measurements
  • Confirm the centre line is straight and correctly offset
  • Ensure the substrate is solid and suitable for fixing bolts