Tierline Retaining Walls Engineered Walls (over 1m)
Once a wall retains over a metre, or carries a surcharge like a driveway, a structure or a building above it, the loads climb fast and a wall that fails on a slope can take the ground and what is on it with it. So this is the wall where we bring the structural engineer design and certification and the council development approval, prepare and lodge the development application, and build it to AS 4678. The engineering and the approval are itemised on the quote, with a realistic timeline, so the over-a-metre line is a number you can see, not folded into a round figure.
What this job includes.
- ✓Structural engineer design and certification on walls over a metre
- ✓Council development approval prepared, lodged and managed to consent
- ✓Walls built to AS 4678 and the NCC, with the footing sized to the load
- ✓Concrete sleeper, core-filled besser, link-block, stone and gabion, engineered
- ✓The engineering and approval itemised, with a realistic timeline
Priced by the face-metre, itemised line by line.
The face-metres and height, the material and the footing named, the drainage as its own line, the engineering and council line if it is over a metre, excavation and access, and the boundary note if the wall holds up a neighbour. Not one round number for a wall.
- 1 Face-metres, height and material. The price broken down by face-metres and the wall height, with the material named: concrete sleeper, core-filled besser, timber, link-block or stone. Not one round number for "a retaining wall".
- 2 The footing and reinforcement. The footing sized to the wall and the soil: a reinforced concrete footing for besser, concrete-set posts dug to depth for sleeper walls, with the reinforcement named. This is the line cowboys skip.
- 3 The drainage, as its own line. The ag-pipe (subsoil drain) along the base, the free-draining aggregate backfill, the weep holes and the geofabric. Trapped water is the number one reason walls fail, so the drainage is on the quote, not left off.
- 4 The engineering and council line. If the wall retains over a metre, the structural engineer design and certification and the council development approval, itemised, with a realistic approval timeline, not folded into a round number.
- 5 Excavation and access. The cut, the machine access on a steep or tight block, the spoil carted away and the tip fees, each a line, never sprung on you at the end.
- 6 The boundary-cost note. If the wall holds up a neighbour boundary, a plain-English note on how the cost usually falls (the benefit / whose-land-is-retained rule), so you can have the conversation. General guidance, not legal advice.
- 7 Warranty and compliance. The 10-year structural workmanship and drainage warranty in writing, and the AS 4678 / NCC compliance with the engineer design where the height needs it.
What happens, step by step.
Free site assessment and soil
We come to the block, measure the fall and the slope, check the soil and the access, and talk through material and height, then put a written quote in your hands.
Engineer design where the height needs it
For a wall over a metre or under a surcharge, the structural engineer designs it to AS 4678 and we lodge the council development application, so it is signed off before we dig.
Itemised quote and start date
The honest quote: face-metres, height and material, the footing, the drainage, the engineering line, excavation and the boundary-cost note. You sign off and we book the dig.
Footings and posts
We excavate, then size and set the footings: a reinforced concrete footing for besser, concrete-set posts dug to depth for sleeper walls. The footings cure before the wall goes up.
Drainage and wall build
The ag-pipe and free-draining aggregate go in behind the wall as it is built, with weep holes and geofabric, so water drains away instead of building up. Then the wall is built to height.
Backfill, finish and handover
We backfill and finish, clear the site, walk you around the wall, and hand over the warranty in writing and the engineer certification and approval paperwork where it applies.
The paperwork behind the price.
Public liability to $20M, and a 10-year structural warranty, all in writing, all on request.
We hold a South Australian builder’s licence, we build every wall to AS 4678 and the NCC, and we carry public liability insurance, so you are covered on site. For a wall over a metre, or one holding up a driveway or a building, we bring the structural engineer’s design and certification and handle the council development approval. The guarantee is a 10-year structural warranty, in writing, covering the structural workmanship and the drainage, the parts that fail first. All in writing, with exclusions named.
Engineered Walls (over 1m): common questions.
Why does a wall over a metre need an engineer?
Do you handle the council development approval?
How much does the engineering and approval add?
What if I am not sure how high my wall is?
Get a free, itemised quote you can actually read.
Tell us what you need. We’ll book a walkthrough and send a quote with the work itemised, not just a number.