Installation of Your Terravault Tree Root Protection System
If you're looking to install a Terravault Tree Root Protection system and your modules are already built and ready to go then follow the installation below.
If you are looking for guidance on building your modules - check out our installation guides.
Prior to the start of your Terravault installation, layout and stake the limits of excavation and horizontal and vertical control points sufficient to install the Terravault units and required drainage features in the correct locations.
Excavate to the correct depth and shape - the base of the excavation should be smooth, level and free of debris. Compact base soil to ensure it is ready for installation.
Ensure that the width and length of the excavation is a minimum of 300mm, in all directions, beyond the edges of the Terravault units.
Layout the Terravault units on the prepared sub base (without the top closed Ellipse plate). Place Terravault Units tightly butt up against each other. Cable tie together to ensure modules do not move apart.
Carefully install side backfill material in the space between the Terravault units and the sides of the excavation in lifts that do not exceed 300 mm simultaneously. Do not compact at this point.
Infill the planting soil in the Terravault modules until it the soil reaches the midpoint.
Once the planting soil has been placed to the midpoint, compact the backfill material previously placed between the Terravault units and the sides of the excavation
Add and compact backfill material until the compacted backfill material is level with the planting soil in the system. Then install one additional 200 mm lift of backfill material, but do not compact it.
Add the remainder of the planting soil in the system. Compact the planting soil by walking over it. Add additional planting soil as needed to keep the level of the planting soil up to the top required level.
Finish adding and compacting backfill between the Terravault units and the walls of the excavations until the compacted backfill material is even with the top of the units, make sure the Terravault units are also well filled and loosely compacted to the top.
Place the closed Ellipse top plate on the units and secure with rubber hammer. Additional planting soil can be filled and brushed into the top plate surface.
Place Geogrid over the top of the filled and capped Terravault system and extend the geogrid beyond the footprint of the Terravault units system to the edge of the excavation.
Install the aggregate base course (including aggregate setting bed if installing unit pavers) over the Geogrid immediately after completing the installation of the grid.
The installation is now ready for paving to be laid above the system.
If needed install geotextile over compacted subgrade. Install the geotextile with a minimum joint overlap of 300 mm between sections of material. Ensure geotextile is laid flat with no folds or creases.
It's worth noting that you should not proceed with the installation when subgrades, soils and planting soils are in a wet, muddy, or frozen condition.