1.  ABOUT VISUAL INSPECTION.

Visual inspection is an inspection made by means of naked eyes. The visual inspection of a structure is the first line of Defence and typically involves the search for large-scale deficiencies and deformities, if any in the structure.

Visual observation is probably the most important of all non-destructive tests. It can often provide valuable information to the well-trained eye. Visual features may be related to workmanship structural serviceability, and material deterioration and it is particularly important that the engineer is able to differentiate between the various signs of distress which may been countered. These include for instance, cracks, pop outs, spalling, disintegration, color change, weathering, staining, surface blemishes and lack of uniformity. Extensive information can be gathered from visual inspection to give a preliminary indication of the condition of the structure and allow formulation of subsequent testing programmes. The visual inspection, however should not be confined only to the structure being investigated, it should also include neighbouring structures, the surrounding environment and the climatic conditions.

The importance and benefits of a visual survey should not be underrated. Often the omission of what appears to be insignificant evidence can lead to a wrong conclusion being made.