Sustainable Ramp Drainage for Orakei Apartments

Allproof’s 300 millimetre clear opening commercial channel was selected for its sustainability, performance, and long-term durability.

Designed by +MAP Architects, 22 Karori is a luxury apartment development situated on the Auckland city fringe, overlooking the Waitematā Harbour towards Devonport. With sustainability and energy efficiency at the centre of +MAP’s design philosophy, the building has been developed to be lived in, and loved, by generations to come.

Drainage Requirements for a Basement Car Park Ramp

Basement and semi-basement car parks often present unique hydraulic challenges. As rainwater travels down a ramp, it increases in velocity and can hydraulically bridge narrow drainage openings. This makes the width of the catchment area critical to ensure effective surface water removal during peak rainfall.

For 22 Karori, Allproof’s CC300 commercial channel was selected for its 300 millimetre clear opening, providing a wide and reliable catchment to prevent water from bypassing the drain during high-flow events. The system was installed both on the ramp and within the car park itself to ensure consistent performance across all trafficable areas.

Product Selection for Performance, Safety, and Durability

Ramp Drainage – Heelproof Cast Iron (HCI) Grating

The ramp required a grate that could withstand vehicle loads, weather exposure, and continuous water flow. The HCI heelproof grate was selected due to its:

• • Class D load rating for wheel loads up to 8,000 kilograms (AS 3996)
  • Slip resistance rating of P5 (AS 4586), suitable for steep and wet surfaces
  • High durability and resistance to long-term wear
  • Suitability for environments with accelerated run-off and sudden load impact

These attributes make HCI an ideal choice for vehicle ramps where water management and surface safety are both critical.

Internal Car Park Drainage – 316 Stainless Steel Wedge Wire Grating

Inside the car park, the design team selected Allproof’s 316 grade stainless steel Wedge Wire grate, providing:

• • A clean architectural appearance in line with the building’s premium aesthetic
  • Excellent corrosion resistance in enclosed or partially ventilated spaces
  • Smooth top finish for improved pedestrian and vehicle comfort
  • Structural performance that complements the CC300 channel body

Wedge Wire is a preferred choice for premium developments due to its durability, low maintenance requirements, and high-end finish.

A Sustainable, Locally Manufactured Solution

The CC300 system is manufactured locally in Allproof’s Toitū enviromark® bronze certified facility, supporting the project’s sustainability objectives. Using a New Zealand-made product reduces transport emissions and supports the circular economy through Allproof’s established recycling programmes.