Adbri Versawall retaining walls and steps with Adbri Quadro paving creating 92m2 of usable and livable space ACQ treated hardwood with cup bolted uprights 800 mm ACQ hardwood timber retaining wall with M10 Cup bolts Retaining wall Posts at 2.4m centres 200 x 100 Hardwood posts on a 10 degree pitch with 2.4 m hardwood sleepers for this 1 meter high retaining wall. 200 x 100 Hardwood post on a 10 degree pitch with 2.4 m hardwood sleepers for this 1 meter high retaining wall with 2.4 meter return. hardwood timber retaining wall