RFI - 25_06_23_AIA_ SLa_3 Allambi Rise_V2

9.7.1   HARD SURFACE REMOVAL
Where the Project requires the removal of existing roadways/hard surfaces adjacent to the
subject retained trees, these require careful removal overseen by the onsite Project Arborist
working alongside the contractors.

Cut sections of the old surface can be removed with the use of an excavator sitting and working
away from the tree. Hand jackhammers or concrete cutting tools may be required when in
proximity to the tree/roots. Begin the process of removal in the area closest to the tree and
work removing smaller sections away from the tree until in a safe location. Machinery is not to
be used on non-protected or bare ground within the TPZ or Exclusion Zone.

The excavation of any ground within or adjacent to retained trees should be cut
perpendicularly to the tree to reduce the likelihood of roots being split or damaged
longitudinally and is to be overseen by the Project Arborist.

Exposed roots are to be covered with either damp hessian or sandy loam to protect the roots
from drying out before the construction of the new surface.

9.7.2   POST-HOLE DIG
The Project Arborist is to be onsite to oversee and guide all works within the TPZ of protected
trees. Ground protection measures can be implemented.

A Post-Hole can be any form of cylindrical hole in the ground that facilitates the installation of
a post, e.g., fence post or pier foundations. Depth will be determined by engineering
requirements.

The top 1m of all post-holes inside the calculated TPZ of retained trees will be created with a
Hydro-Vacuum Excavator (Sucker Truck) to determine the presence of tree roots. Below this
depth, an auger can be used to remove the remaining spoil as the presence of roots below
this on this site is unlikely.

The excavator operating the augur is to be sat outside the calculated TPZ wherever possible
to reduce ground compaction. A combination can be used of a larger machine with greater
reach and a smaller mini excavator (under 3.5 tons) when access to the TPZ is required.

Pole-hole spoil is to be spread away from the TPZ of retained trees unless otherwise directed
by the Project Arborist.

Large roots over 100mm will be retained wherever possible, with the post hole relocated.

Where roots between 50-100mm in diameter are located, the Project Arborist will assess them
on an individual and species basis and determine if the hole is required to be relocated or if it
is suitable for the Project Arborist to prune.

Roots under 50mm in diameter will be cleanly cut by the Project Arborist when uncovered.

Turning and screwing of machinery tracks and wheels is to be kept to a minimum.

The site within and adjacent to the retained tree’s TPZ is to be left clean of construction waste
and the mulch and spoil to be evenly spread as directed by the Project Arborist.




25_06_23_AIA_ SLa_3 Allambi Rise_V2                                                   Page 31 of 38