2600m² Industrial Timber Treatment Building Design

Date - Current

When one of New Zealand’s largest timber companies needed to modify and extend its existing industrial process building to increase processing and storage capacity, they called in GRIT to design and execute the brownfield industrial project.


Located in the Central North Island region, this Copper Chrome Arsenate (CCA) Treatment Plant was originally built in 2016 for one of New Zealand’s largest timber companies. This rapidly growing timber company specialises in processing operations for kiln drying, planing, treating, and remanufacturing timber.

Having anchored the region as the wood processing capital of New Zealand, the company is committed to continually upgrading production facilities to enable further product range development, market base growth, and long term success.

The Challenge
While the existing CCA treatment plant originally met the company’s production and storage needs, the demands of the construction industry continued to grow. Four years on and the client had outgrown the existing plant. The client wanted to ramp up distribution of CCA treated timber to their consumers but were limited by the tonnage of CCA treated timber that could be stored within the existing facility.

They knew they would need to increase the size of the CCA treatment plant if they wanted to package and distribute more treated timber to consumers while meeting New Zealand’s strict durability standards.

So, in November 2020, the client approached GRIT to provide civil and structural design services for a proposed modification and extension to their existing CCA Treatment Plant.

GRIT’s Approach
We worked closely with the client to fully understand their desired project outcomes in terms of purpose, durability, compliance, and acceptable levels of risk. Our team of civil and structural engineers then went to work designing a solution that met the client’s requirements, minimised operational impact, and adhered to New Zealand safety regulations and standards.
GRIT’s design included modifying existing buildings to improve layout efficiency for operations, and the design of an innovative industrial slab drainage system to ensure excess CCA can be re-used within the plant’s process system.

GRIT are also providing the following services as part of this project:

  • concept stage optioneering
  • reverse engineering for old structures
  • existing building seismic assessment and analysis
  • durability advice
  • safe installation methodologies
  • construction monitoring services

The Outcome
GRIT’s civil and structural design will facilitate the construction of a 2,600m2 extension to the existing CCA Treatment Plant. This will equate to a 120% increase in storage capacity for CCA treated timber on site and contribute to the client’s goal of increasing the plant’s timber processing capacity. Construction of the project is underway.

Key Highlights

  • Design of fit-for-purpose 2,600m2 extension to existing CCA Treatment Plant
  • Projected increase of 120% storage capacity for CCA treated timber on site
  • Design of 30m long Glulam rafters and 10m high cantilever steel columns/timber poles to improve layout efficiency for plant operations
  • Design of fibre reinforced industrial slab to withstand 29T front axle forklift loads
  • Excess CCA will be able to be re-used within the plant’s process system

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