Page 29 - Build 152

stretchers
sleepers
headers
compacted base laid to batter of 1:4
Proprietary timber crib walling.
topsoil
granular ll
excavated face
slotted drain to stormwater
Figure 2
height in accordance with manufacturer's requirements or 1.5 m max., whichever is less
precast concrete crib wall laid to a batter of 1:4
header stretcher
concrete foundation laid to correct batter
Figure 1). They are built of concrete or stone or a combination and laid on good ground as defined by NZS 3604:2011.
Crib retaining wall
Crib walls also retain by mass but the mass or weight is obtained from the backfilled material placed in the wall. They consist of either H5- treated timber or concrete interlocking header and stretcher units laid in tiers alternately, with a 1:4 backward slope or batter.
Once the units are laid, the whole structure is backfilled with granular drainage material (see Figures 2 and 3). The first stretcher course is laid on a concrete foundation or a compacted base to create the correct batter. They may have the outer section of the wall filled
Figure 3
Proprietary concrete crib walling.
Build 152 — February/March 2016 — 27