50 mm diameter or less

Test holes must be reinstated to finish flush with the surface by any of the following methods:

Using a fine aggregate bound with cement or bitumen for the upper layers as appropriate, and compacted in layers 100 mm thick, or less.
Using a self-compacting proprietary product.
Using a flexible sealing plug. The void beneath the flexible sealing plug must be reinstated using sand and cement mix or a proprietary product.
1. In bituminous surfaces, all sealing plugs must be coloured black (or dark grey).
2. In modular or concrete surfaces, sealing plugs must be coloured white (or light grey) or black (or dark grey) as appropriate.

If a flexible sealing plug becomes dislodged during the guarantee period, the undertaker must replace it.