Kāinga Ora’s 139 Greys Ave site is undergoing a redevelopment to increase the available apartments from 87 to 276 over 16 floors and bring the quality of residential units up to a 7 Homestar rating. 139 Greys Ave includes commercial / retail spaces, a medical area and various other facilities needed to care for the diverse needs of its inhabitants.
The redevelopment has been planned to address social and environmental factors from construction through to the full life span of the complex, this is done by using its social procurement initiative and consideration of the facilities provided on site. Kāinga Ora developments place heightened attention to durability and ongoing maintenance costs of projects ensuring broader economic efficiency and reduced impact on customers through the lifetime of the development.
A key element to the design of each unit is a polished stainless steel shower tray which provides a durable and easy to maintain solution for an area exposed to high levels of moisture. The stainless-steel tray acts as an impermeable barrier minimising the risk of moisture escaping the enclosure and impacting structural elements or adjoined tenancies. Apendix A from Ngā Paerewa Hoahoa Whare: Design Requirements stipulates a polished stainless steel tray for its physical characteristics as it is low maintenance, corrosion resistant, durable, no red listed contents and has a high tensile strength.
When designing high density projects, or even medium density with apartments vertically or horizontally adjoined, the units will be designed as a fire cell, having fire resistant separations between cells inhibiting the spread of fire. Any penetration in the fire-resistant substrate separating fire cells, such as a shower floor waste gully, needs to be fire rated using a tested solution. The passive fire protection (PFP) product needs to be tested or assessed accurately to the exact install scenario as outlined in NZBC C3 Clause 4.4.3 using AS1530.4 - 2014 and AS4072.1 - 2005.
The shower tray system originally selected for 139 Greys Ave did not allow for a tested passive fire device to be installed as no solution was available to the specifications of the installation. Auckland Council require that an alternative solution should only be used if a tested solution is not readily available. Therefore, a substitution was required and Allproof’s exposed stainless steel shower tray was selected by Express Plumbing who presented the solution to Kāinga Ora for approval as Allproof have a tested PFP solution for this system.
The Allproof shower tray utilises a PVCu floor waste gully rather than a welded in easy clean system. A PVCu pipe penetration through the floor slab reduces the aperture of the opening and the use of a plastic pipe allows for a fire collar to be installed. Allproof supply all these products with testing on a wide range of substrate materials, offering an adaptable system fully compliant to the NZBC and relevant standards. This solution has been fully tested removing any requirements for engineering judgements creating an easy to specify and install fire rated floor waste and shower tray.
An added benefit to this solution is the removal of an easy clean waste. Easy clean wastes provide an excellent solution for squat floor situations where space does not allow for a floor waste gully. However, an easy clean contains additional removable componentry to create a water seal which can lead to increased maintenance and the risk of these components becoming lost, thus requiring replacements. If space allows, Allproof recommend the use of a floor waste gully as these are considered self-cleaning, have no removable components other than the grate and provide a higher flow rate than an easy clean.
Allproof manufactured the exposed shower trays to suit the construction schedule of 139 Greys Ave, supplying them to site in stages aligned with construction phases through the building levels. Allproof were able to support Express Plumbing with install methodology and implement feedback gained from site as the project developed.
The project benefitted from having specialised insight from a local manufacturer that spans multiple product ranges and categories providing integrated systems. Allproof were able to provide a solution to suit the criteria required by Kāinga Ora and the NZBC for high density projects.
Further to the installation of shower trays, each apartment contains an Allproof vinyl floor waste drain, hot water cylinder tundish, passive fire protection, acoustic pipe lagging and Allthrough balcony drainage. This wide range of products included in one Kāinga Ora project displays the diversity and ability of Allproof Industries as a New Zealand manufacturer.
- Ngā Paerewa Hoahoa Whare Design Requirements, Kāinga Ora
- C/AS2 Acceptable Solution for Buildings other than Risk Group SH
- Auckland Council position statement for acceptance of fire stopping
Note: The product selection of Shower Trays and Passive Fire Systems for Greys Ave were project-specific solutions proposed by Express Plumbing. While the products satisfy the requirements outlined in Ngā Paerewa Hoahoa Whare: Design Requirements, it should be noted that Kāinga Ora does not endorse products and that the preceding article exclusively outlines one solution for a specific project case study. Refer to Kainga Ora design guides and details in regard to product requirements.
For specification support and project specific solutions please reach out to Allproof Industries.