Retaining walls in Hamilton and across the Waikato

Timber pole and concrete walls, built on a proper foundation with the drainage done behind them. The part you cannot see is the part that decides how long it lasts.

Finished timber retaining wall with a stepped return alongside a new build

Who builds retaining walls in Hamilton and the Waikato?

Trident Earthmoving builds timber pole and concrete retaining walls across Hamilton, Cambridge and the wider Waikato. Every wall gets drainage coil, free draining metal backfill and an outlet that runs, poles are set in concrete to depth, and walls that need engineering are built to the approved design. Excavation, the wall and the backfill are done by one crew, on one price.

Prequalified
Tōtika certified
Accuracy
Grade control on the 313F
Fleet
3 to 14 tonne, plus hired plant
Based
Whakamaru, Waikato

What makes a wall last

Most retaining walls that fail do not fail because of the timber. They fail because water built up behind them and nobody gave it anywhere to go. Water is heavy, and a wall designed to hold soil will not hold soil plus a season of trapped groundwater. So we build the drainage first and the wall second. Drainage coil at the base, free draining metal backfill, and an outlet that actually runs. Then the wall in front of it.

Drainage first, wall second

Drainage coil at the base, free draining metal backfill, and an outlet that runs. Walls fail when water builds up behind them, so that is the part we get right before anything visible goes up.

One crew, start to finish

Excavation, poles, lagging and backfill all done by the same team. No waiting on another trade, and one person accountable for how the wall performs in five years.

Timber pole retaining wall under construction with drainage metal backfill behind it
Timber pole retaining wall under construction with the drainage trench open behind it

Retaining walls that stay put

We build timber pole walls and concrete walls, from a low garden terrace up to structural walls on a building platform. Poles are set to depth in concrete, rails and lagging go on square, and the backfill goes in behind in layers rather than all at once.

Where a wall needs engineering, we build to the approved design and the levels that come with it. Where it does not, we still build it like it does.

How a retaining wall job runs

  1. Look at the site. We check the height, the ground, where the water goes and whether it needs engineering.
  2. Quote the job. One price covering excavation, the wall and the drainage behind it.
  3. Dig and set. Excavation, then poles set to depth in concrete.
  4. Build and drain. Lagging on, drainage coil and metal in behind, backfill in layers.
  5. Tidy up. Ground reinstated and the site left clean.

What does a retaining wall cost?

We quote every wall on site, because the same length of wall can cost very different amounts depending on the situation. These are the things that actually move the number:

  • Height. The taller the wall, the deeper the poles and the heavier the timber. Height also decides whether you need an engineer and a building consent, so it is the single biggest factor.
  • Ground conditions. Rock, clay and wet ground all slow the digging down. Soft ground can mean deeper footings.
  • Access. If we can get a machine and a truck alongside the wall it is a straightforward job. If everything has to be barrowed in, it is not.
  • Drainage. Every wall we build gets drainage, but where the outlet has to run a long way, that adds to it.
  • Materials. Timber pole walls and concrete walls price differently, and so do the finishes.

On consents, the general rule in New Zealand is that a retaining wall up to 1.5 metres high, with nothing loading the ground above it, does not need a building consent. Go above that, or put a driveway or building near the top of it, and it usually does. We will tell you which side of that line your wall falls on before you spend money on it, and your council is the final word.

Where we work

Based at Whakamaru, we cover Taupō, the South Waikato, Waipā, Hamilton and out to Rotorua and the King Country. Here is the patch, and what we tend to see on the ground.

Common questions

Still not sure? Give us a call and we will talk it through.

Does my retaining wall need council consent?

In most cases a wall over 1.5 metres high needs a building consent, and lower walls can also need one if they carry a surcharge such as a driveway or a building above. We will tell you where your wall sits and what it needs before you commit to anything.

Do you do the drainage behind the wall?

Yes, always. Drainage coil at the base and free draining metal backfill behind the wall is standard on every wall we build. Walls fail because water builds up behind them, so it is the single biggest factor in how long one lasts.

Timber or concrete?

Timber pole walls suit most residential and lifestyle block jobs and cost less. Concrete makes sense for higher walls, a longer design life, or where the look matters. We will talk through both for your site.

Contact us

Tell us what you are dealing with and we will come and size it up.

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