Measure missing concrete

The 3D defect tool works out where the sound face used to run, from the good concrete just outside your outline, and measures what is missing behind it. You do not choose the reference. The tool works on a vertical wall as well as on a slab.

Before you begin

• Find intact, reasonably flat concrete all the way round the damage. The flatter that surrounding concrete is, the more the result can be trusted.
• The outline must be at least 10 cm across. A smaller outline is refused.

To measure missing concrete

1. On the toolbar, click Advanced ▸ 3D defect.

2. Click points around the damage, on sound concrete just outside it — not on the damage itself.

3. To close the outline, click the first point, press Enter or double-click.

4. Correct the outline if you need to: drag a point to move it, click the outline to add a point, double-click a point to remove it.

5. In the Measurement panel, click Measure defect.

   The status line says that the tool is fitting a reference to the surface around the outline. When it has finished, the figures appear at the top of the panel.

6. Read the result:

   Figure	Meaning
   Missing	How much concrete has gone from the face, with a quality word: Good, Fair or Indicative. Not measurable means no figure can be given
   Extra material	Surface that stands out past the sound face — a patch, a repair, or a face that is not flat. Shown only when there is some. Never subtracted from the missing figure
   Deepest point	The deepest single spot in the damage, measured in from the sound face
   Affected area	The damaged part only, not the whole outline you drew
   Surface roughness	How bumpy the sound concrete around the damage is. The rougher it is, the less certain the missing figure

If you change the outline after measuring, click Measure defect again — the panel says the figure is not measured yet.

To read why a result is uncertain

1. In the Measurement panel, click Explain.

   Notes appear where they apply — for example, how much of the figure was filled in where the capture could not see the bottom of the damage, or why nothing was measurable.

Important

The quality word describes the measurement, not the condition of the concrete. A volume is never printed with a ± sign; the word carries the uncertainty. See Quality words.

If the result is “Not measurable”

The sound concrete around the outline is bumpier than anything found inside it. Read this as no detectable loss, not as a small one. Trace a new outline around the flattest intact concrete you can find, and look at the source photographs of the point to judge the damage itself.