Scaling describes the removal of loose non detached rock, soil and vegetation on the face of a slope using hand tools such as scaling bars, shovels and chain saws. Tree roots growing in fractures on the rock face can further widening the fractures causing rock falls. Also, movement of the trees by the wind produces leverage by the roots on loose blocks. The general loosening of the rock on the face by tree roots also permits increased infiltration of water which, in temperate climates, can freeze and expand and cause further opening of the cracks. On steep slopes, workers are usually supported by ropes, anchored at the crest of the slope. A suitable type of rope for these conditions is a steel-core, hemp rope that is highly resistant to cut and abrasion. The scalers work their way down the face to ensure that there is no loose rock above them.
Figure 11: Rock buttress used to control unstable slope (Schuster and Krizek, 1978).