Extending capacity at a busy timber treatment plant
With capacity at its Copper Chrome Arsenate (CCA) treatment plant maxed out, one of New Zealand’s largest timber companies - Red Stag Timber - turned to GRIT to design a major expansion.
Located in the Central North Island, the facility housed the company’s kiln drying, planing, treating and remanufacturing operations. As demand for their product surged, so too did the opportunity to grow their market. But the existing CCA treatment plant had reached its limits - without additional processing and storage capacity, Red Stag couldn’t fully capitalise on the increased demand.
Increasing capacity without disruption
The challenge was twofold: create a 2,600m² extension that would more than double storage capacity, and deliver it in a live environment with minimal disruption to existing operations.
GRIT worked closely with the Red Stag team to understand their operational priorities, long-term goals and acceptable levels of risk. Our civil and structural engineers then collaborated with them on a design that modified the existing building layout to improve efficiency, while seamlessly integrating the new extension. The design included reverse engineering of older structures, seismic assessment of existing buildings, and smart installation methodologies that would minimise downtime and ensure safety.
Innovative improvements
Several innovative design elements were incorporated to deliver maximum value. A 30m-long Glulam rafter system and 10m-high cantilever steel columns/timber poles were used to improve layout efficiency and structural performance. The industrial slab footing was fibre-reinforced and engineered to withstand 29-tonne front axle forklift loads, ensuring the upgraded facility could handle daily heavy use.
GRIT also supported the design of an advanced slab drainage system, enabling excess CCA solution to be safely collected and re-used within the plant’s process system. In combination with this, a wheel-wash system was incorporated to prevent CCA contamination outside the building. This not only reduced waste and environmental impact, but also maximised efficiency.
Close collaboration with the client’s operations team ensured the design was practical, safe to install, and aligned with production requirements. Construction monitoring and clear communication throughout the process gave the client confidence that the expansion could be delivered with minimal disruption to the running plant.
