Airspade Root Investigation and Construction Supervision

Client: 4Delivery Limited
Location: 4Delivery Limited

4Delivery Limited proposed to replace outdated water treatment facilities with new modern equipment on a site in the Isle of Wight. As part of the project, a hard standing access road and turning circle were required. The site bordered woodland and trees surrounded the site on all sides.

The turning circle crossed the root protection areas of several retained trees. It would be normal practice to construct the turning circle on a cellular confinement system directly onto the existing surface (without excavation). This was not feasible due to the existing topography of the site. Additionally, the point at which the turning circle met the public highway needed to be excavated so that the road levels matched.

As a condition of the planning application, a root investigation carried out by suitably qualified arboriculturalist was required. PJC Consultancy was commissioned to carry out the root investigation using our airspade.

The airspade uses an air compressor to blast soil away from tree roots. This reveals both the structural and fibrous tree roots without damaging them. The excavation is backfilled following completion of the excavation to prevent desiccation of the tree roots. The tree roots can be left exposed for a number of days, however they would need to be wrapped in hessian cloth to protect them from the elements (such as frost).

Our root investigation took the form of a trench along the edge of the proposed turning circle closest to the trees. As and when we discovered significant root growth or structural roots, we used the airspade to identify which trees the roots belonged to. A number of trees had recently been felled from the site however their roots would remain in place for quite some time. Only roots from live trees could be considered a constraint to development.

Photographic evidence was required to discharge the planning conditions, and numerous photographs were taken during the excavation.