AS4419 Soil is a premium, engineered landscape soil formulated to comply with Australian Standard AS 4419 for soils used in landscaping and garden applications.
Structural Soil
Structural Soil is a specialised engineered growing medium that combines high-quality soil with large 40–60mm ballast rock to create a load-bearing, root-supportive matrix. The large, angular ballast stones form a strong stone skeleton, while the soil occupies the voids around and between the rock, providing space for roots, moisture, and air.
Additional Information
Additional information
The ballast component is typically crushed rock in natural grey tones (light to dark grey), with sharp, irregular faces that interlock under load. The soil fraction is dark, granular, and slightly compacted, binding around the stones and filling gaps without collapsing the structural framework. This design allows pavements and hard surfaces to be built above while still enabling healthy tree root growth beneath.
Key characteristics:
- Blend of 40–60mm angular ballast and structural soil
- Load-bearing stone skeleton with soil infill for root growth
- Supports pavements and hardscapes while allowing trees to thrive
- Engineered for urban tree pits, streetscapes, and high-load landscapes
Usage
Structural Soil is widely used by councils, landscape architects, civil contractors, and developers across urban infrastructure and streetscape projects:
Urban Tree Planting Under Pavements
- Installed beneath footpaths, shared paths, plazas, and paved areas to allow trees to grow in confined urban spaces.
- The ballast carries structural loads, while the soil provides a continuous rooting volume for street trees.
Car Parks & High-Traffic Hardscapes
- Used under car parks, driveways, and hardstand areas where trees are integrated into paved environments.
- Helps reduce surface failure and trip hazards caused by root heave by directing roots into the structural soil zone.
Boulevards, Median Strips & Streetscapes
- Installed in roadside verges, medians, and boulevard plantings where adequate rooting volume is otherwise limited.
- Supports long-term tree health, canopy development, and urban cooling benefits.
Engineered Root Zones
- Suitable for engineered tree pits and root paths, where coordinated with irrigation, aeration, and surface design.
Application Tips:
- Structural Soil should be installed to the project’s engineered specifications, including depth, compaction, and layer build-up.
- Avoid over-compaction that could collapse soil pores, but ensure sufficient compaction for load-bearing performance.
- Often used in combination with root barriers, aeration pipes, irrigation lines, and structural pavements as part of a complete system.
- Always follow landscape architect / civil engineer details and local authority standards.
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