Non-invasive root investigation

Down to Earth operate a professional Air Spade Investigation service. The Air Spade consists of a hand held lance connected to a compressor, not too dissimilar to a pressure-washer, but rather than water the Air Spade fires a continuous jet of compressed air.

This jet of air effectively removes soil whilst retaining tree roots relatively undamaged, allowing excavation to take place within ground occupied by roots without causing significant damage to trees, unlike with mechanical excavation which, if carried out recklessly can render a tree immediately liable to collapse.


The Air Spade and Planning Permission

The Air Spade is useful for determining the presence or absence of roots within Root Protection Areas (RPAs), which is useful in the latter stages of BS5837 Surveys where a structure is proposed to be installed in the RPA of a retained tree.

Carrying out a trial excavation along the proposed foundation line with an Air Spade allows all significant tree roots to be retained, observed and evaluated, which helps us to draw a balanced conclusion on the likely impact of development on trees and serves to inform of vital next steps, including mitigation measures.

Getting to the root of it


RPAs are only indicative, and in some cases trial excavations within RPAs have revealed no significant roots at all, allowing a development within the RPA to go ahead without worry since it has been proven that there will be no significant loss of roots.

Of course the opposite can occur and significant roots may be found, but once uncovered they can be individually evaluated and either worked around, or pruned as necessary under our guidance. In any case, the Air Spade is a vital tool in assessing the likely impact to trees by delivering results which can really be seen.

Whether you have small scale extension or a large development proposal with trees nearby, contact our experts today to help you obtain planning permission.

Air Spade Investigations for fungal diseases

This service is usually specified by the surveyor when in their opinion a particular pathogen or disorder (such as previous mechanical damage) warrants a below-ground inspection. The Air Spade can be used to inspect the roots of a tree which are not normally visible.

When other signs of defects such as fungal activity highlight a need to go below ground, the Air Spade can carefully remove soil around roots allowing us to get an insight into the problem and draw considered conclusions for future management.

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Areas we cover

We cover most of the South East including Kent, Surrey, Sussex, London and Essex.