AS NZS 3727.1:2016 pdf free.Pavements Part 1: Residential.
4.1 DRAINAGE
The minimum surface crossfall shall be 2.5% (1 in 40 or 25 mm in every 1 m) to ensure surface drainage. In covered areas or pedestrian only areas, a lesser grade may be appropriate provided the aspects of drainage have been assessed.
Where necessary, surface run-off shall be collected in appropriate channels and drains and conveyed to discharge points.
The finished surface level of any pavement abutting a wall shall be below the wall damp-proofing course, shall not obscure any weep holes or drainage openings, and shall be graded away from the building and not obscure any required inspection zones for termite barrier systems.
NOTES:
1 Drainage is an important consideration for preventing softening of subgrades, deterioration of surfacing layers and efflorescence.
2 On poorly drained sites it may be necessary to protect the subgrade from the effects of water. Sub-surface drains of pervious granular material and/or slotted or pervious pipes may be required under or beside the pavement. Geotextile mesh may be provided as a separation or drainage layer.
3 Typical drainage details of the bedding sands for segmental and flag payers are given in Appendix A.
4.2 SUBGRADE
The following conditions shall apply for subgrade:
(a) Loose soil or soil containing organic materials shall be removed.
(b) Formation shall be trimmed to within +0, —25 mm of the design level and compacted if necessary.
(c) Any fill shall be well compacted.
(d) Local soft spots shall be rectified to achieve levels of strength and stiffness similar to the remainder of the subgrade.
(e) Backfill for service trenches shall be compacted in layers no greater than 200 mm to provide levels of strength and stiffness similar to the subgrade.
(f) Any stormwater and sewer pipes and other services below the area on which the pavement is to rest shall be protected from damage during required preparation of the subgradc.
(g) Moisture content of the subgrade and fill shall be adjusted to ensure adequate compaction.
4.3 SUB-BASE
The sub-base shall be prepared in accordance with the following:
(a) Granular sub-base material shall be spread uniformly and adequately compacted in appropriate layer thicknesses and with an appropriate moisture content.
NOTE: The sub-base compaction requirement may be achieved by compacting in layers of 100 mm maximum with at least three passes of a vibrating plate compactor or equivalent.
(b) For lean mix concrete sub-bases, concrete shall be placed and compacted.AS NZS 3727.1 pdf download.