We can provide tree root investigation services for getting planning permission. This may simply require digging a trial hole against a boundary wall to see if it is an effective root barrier, in order to permit development, or require trenches following proposed building footprints. At the other end of the scale if can be used where development within a tree root protection area cannot be avoided. Root investigation may reveal that there are no significant roots present or that the scheme can be designed around tree roots.
Roots are unpredictable, especially in urban areas, and frequently defy what would be a typical spread and depth for an open grown tree in the countryside. This means the results are as unpredictable. However, BS 5837:2012 requires root investigation where development takes place in a root protection area. So it can be an necessary step in demonstrating compliance with best practice to gain planning permission. It also requires the method to use a compressed air tool (like an Airspade) to avoid harming roots during excavation. However, there are other methods that can be deployed according the the circumstances, as in many urban sites, use of an Airspade is not practical.
Two of the most common methods apart from careful hand digging are as follows.
Tree Root Investigation with an Airspade
An airspade is a compressed air lance that can blow soil away from roots without causing significant damage or severing them. The other bonus is that it will not damage underground services.
Tree Root Investigation with Root Radar
The radar is a more expensive option than Airspade, and has advantages and disadvantages over it. While it cannot identify roots under a certain size, it can identify roots we would consider significant. It can also scan through hard surfaces to a depth well below what can easily be achieved with the Airspade. Also, the survey time is predictable, and not reliant on soil conditions, which have a hughe impact on the effectiveness of an Airspade.