Project Overview

 

Location: Herrick Street, Napier

Architect: Pynenburg & Collins

Builder: Built Solid HB

Project Manager: Rubio’s Pro LTD

Engineer: QPOD Engineering Team

Project Type: 75 m² – polished concrete finish

The client’s vision for a highly polished concrete floor drove the need for a precision-built foundation capable of delivering minimal movement over time. The site’s geotechnical profile, however, required careful engineering to meet seismic and settlement demands.

Site Challenges

 

  • Geotechnical Classification: Foundation Technical Category 2 (TC2) with moderate liquefaction vulnerability.

  • Soil Profile: Sandy silts over non-engineered fill, underlain by interbedded clays/silts/sands and medium dense sands to 5.8 m.

  • Seismic Considerations: High liquefaction risk requiring reinforcement to minimise differential settlement.

  • Architectural Requirement: A polished concrete floor with a 100 mm topping for grinding depth.

Implementation

  • Subgrade Preparation: Removal of surficial topsoil and non-engineered fill, founding the slab on competent natural alluvial sediments.
  • QPOD Installation: 133 closed two-side pods with interlinked spacers and end caps to match design layout.
  • Reinforcement Placement: Cages installed in perimeter beams; rib reinforcement with R6 links at 120 centres through the slab.
  • Insulation Layer: Continuous 50 mm XPS installed to reduce heat loss and improve R-value.
  • Concrete Placement: Continuous pour for monolithic performance, followed by a 100 mm topping pour for the polished surface finish.

XPS supplied by QPOD placed under pods to boost r-value outputs

Environmental Impact

 

  • From a sustainability standpoint, the QPOD components installed here comprised:

  • 133 closed two-side pods (11,837 plastic bottle equivalents)
  • 15 end caps (105 plastic bottle equivalents)
  • 93 × 100 mm spacers (279 plastic bottle equivalents)
  • 185 × 300 mm spacers (1,110 plastic bottle equivalents)
  • 45 × 400 mm spacers (405 plastic bottle equivalents)


Total: 13,736 bottle equivalents diverted from landfill

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All pods are made right here onsite in Hawke’s Bay from 100% recycled materials.

Results

  • Seismic Resilience: Reinforcement strategy tailored to mitigate TC2 liquefaction effects.

  • Thermal Efficiency: XPS insulation delivering consistent under-slab performance.

  • Aesthetic Finish: Polished concrete floor to be achieved without visible cracking or surface defects.

  • Sustainability Impact: Over 13,700 recycled bottle equivalents embedded in the foundation structure.

  • Efficient Build: Modular QPOD system reduced labour time and site disturbance, and was easy to deliver and install on a tight site.