Drainage
Clean drainage gravel behind a retaining wall, usually 300 mm wide for the full height, lets water get to the ag-pipe instead of pushing on the wall.
What you need
- BackfillDrainage gravel (20mm Aggregate, Drainage)300 mm wide, full height, from $36.30/t ex GST at the quarry
Tips
- Wrap the ag-pipe in a sock, or line the trench with geofabric, so fines don't clog it.
- For a pipe trench, choose "Pipe bedding and trenches" in the calculator.
How much you need
Enter your measurements, then price the tonnes delivered to your address.