BS5837 (2012) Trees in relation to design, demolition, and construction – Recommendations, defines a root protection area (RPA) for trees. This is a tool to help us understand the minimum area of roots and soil need to maintain the viability of the tree.
Where proposed development encroaches within the RPA, it is necessary to provide evidence of the presence and depth of roots, to inform whether the encroachment is acceptable or to inform possible design solutions where tree roots are found.
As well as hand excavations, specialist technical equipment exists to establish the presence of roots underground, which avoids the need to dig up the ground:
Arboradix: This is a root diagnostic tool which helps us define the extent and location of a tree’s root system to a depth of 500mm.
Tree Root Radar: Ground penetration radar which scans the ground and can identify the location, depth and density of tree roots up to a depth of 2000-3000mm