Project overview

As part of a broader campus upgrade at Macquarie University, existing established and protected trees surrounded a key exit point from a newly constructed building. Arborist requirements meant tree roots close to the surface could not be disturbed, presenting the client and architect with a complex challenge: Deliver a fully accessible, slip-resistant pathway without compromising root structures, while ensuring continued water infiltration to maintain tree health.

To achieve this, StoneSet proposed a Flexi-Base permeable paving system, specifically engineered for sensitive root zones. The system incorporates a stone and recycled rubber base bound with a non-UV variant of StoneSet’s resin technology, creating a permeable, structurally robust yet highly flexible layer capable of absorbing minor root movement.

A StoneSet Premium UVR resin-bound top layer was installed above the Flexi-Base to provide a durable, slip-resistant, and visually refined surface with high permeability—ensuring long-term accessibility performance while supporting ongoing soil hydration.

Delivering functional permeable surfaces in environmentally sensitive areas often requires site-specific design adjustments. As StoneSet is mixed and laid on site prior to curing, the system allows for real-time specification adaptation. While the typical build-up includes 100mm drainage aggregate, 32mm Flexi-Base, and 18mm StoneSet, thicknesses were locally adjusted to prioritise root protection without compromising structural performance.

To further mitigate the risk of future movement and cracking, fibreglass reinforcing mesh was installed between the Flexi-Base and StoneSet layers. A triple-layer Mesh’N’Go separation layer was also incorporated between the Flexi-Base and drainage aggregate to enhance load distribution, prevent material migration, and improve long-term system integrity.

Due to the rapid curing time of StoneSet’s non-UV resin system, the entire system could be laid on the same day for efficient installation.