CORE TRP Tree Root Protection Panel | 50–200mm Depths | No-Dig Cellular Confinement System

CORE TRP is a cellular confinement panel used to create load-distributing surfaces over sensitive tree-rooting areas.

It is designed for tree root protection beneath pedestrian routes, driveways, access roads and other trafficked surfaces. Depending on the selected depth and complete system design, it can be used for pedestrian, vehicle and construction-access applications.

Yes. CORE TRP is specifically designed for above-ground, no-dig construction within Root Protection Areas (RPAs).

Rather than excavating a conventional sub-base, the cellular confinement system is installed over the existing ground to help distribute loading.

However, the panel itself does not automatically provide approval to build within an RPA. The complete construction, including ground preparation, membranes, aggregate, panel depth, edge restraint and finished surface, should be assessed against the project’s arboricultural and planning requirements.

Does CORE TRP comply with BS 5837?

CORE TRP is available in 50mm, 75mm, 100mm, 150mm and 200mm depths.

The manufacturer’s planning chart illustrates increasing depths for increasing loads, from pedestrian/light-duty applications through to heavy vehicle and plant loading.

The correct depth also depends on the existing ground strength, proposed finished surface, frequency of traffic and complete build-up.

For project-specific advice, provide the anticipated loading, surface specification and ground information to our technical team.

Each panel coveres 25m2

The CORE TRP panel is the cellular confinement component of the wider tree root protection system and is sold as an individual panel.

Other components may be required depending on your project, including:

CORE TRP30 membrane;
CORE TRP Geogrid;
panel connectors;
installation pins;
CORE SubFlow20 or SubFlow40 aggregate;
CORE TRP10 membrane;
edge restraints; and
the finished surface material.

Unless specifically stated against the product variation or package, these additional system components should not be assumed to be included with the panel.

Use a clean, angular, free-draining aggregate with no or very low fines.

The manufacturer’s specified options include a 4/20mm clean angular aggregate, and a 20/40mm clean angular aggregate.

The stone should be screened and washed so that it remains porous after installation.

MOT Type 1, high-fines crushed stone and flint gravel should not be used as TRP cell infill.

Yes, CORE TRP can form part of a no-dig driveway construction close to established trees.

The system distributes vehicle loading through its cellular confinement layer while retaining a porous construction.

The driveway specification must still account for the Root Protection Area, expected vehicle loading, ground strength, edge restraints and proposed permeable surface.

For driveways within an RPA, arboricultural approval of the complete build-up may be required.

Yes.

CORE TRP can be used as part of a temporary access system where construction traffic needs to travel across sensitive rooting areas.

The manufacturer’s guidance includes temporary access for construction traffic and heavy plant when an appropriate system has been designed for the expected loading.

Temporary surface layers can subsequently be removed, with the underlying system either removed or adapted for permanent use depending on the approved project specification.

Yes.

For permanent applications, the filled CORE TRP cellular layer forms part of the retained sub-base and is finished with the specified porous or permeable wearing course.

Suitable finishes can include gravel grids, grass reinforcement, permeable paving, porous asphalt and appropriately designed resin-bound construction.

CORE TRP is designed specifically to minimise excavation within sensitive rooting areas.

The system is generally constructed above existing ground as a no-dig solution.

Minor preparation may be required depending on site conditions, but significant excavation, removal of roots or mechanical compaction within an RPA should not be undertaken without appropriate arboricultural guidance.

Where surface roots or substantial changes in level are present, seek project-specific advice before installation.

A standard landscaping or weed-control membrane should not automatically be substituted for the specified TRP membrane.

The manufacturer’s system uses a specialist TRP geotextile selected to provide the tensile strength, separation, permeability and puncture resistance required for the application.

Use the membrane stated within the approved CORE TRP specification.

Not in every installation.

CORE TRP Geogrid provides an additional reinforcement layer and may be specified where greater load distribution or protection of the underlying membrane is required.

The requirement depends on anticipated traffic loading and existing ground conditions.

The manufacturer’s guidance references a minimum separation between new surfacing and significant buttress roots.

The appropriate distance can vary according to the tree, root structure and project conditions, so the final relationship between the new surface and existing roots should be agreed with the supervising arboriculturist.

Do not cut or excavate significant roots simply to accommodate the proposed surface.