Prefabricated construction

“James Hardie even supplied the sheets pre-cut to size in the most efficient layout.”

Prefabricated construction offers numerous advantages but tight tolerances mean product choice is crucial. On a project for Auckland University completed in 2011 James Hardie’s Secura Interior Flooring was the right fit for the job.

At 14 levels, University Hall for Auckland University was a New Zealand first for prefabricated construction when it was completed in 2011. The student accommodation block comprised 468 volumetric units or “pods” that were constructed by Stanley Group at their Matamata factory. Each unit was fully finished with bed, wardrobe, desk, carpet, joinery and all services before being wrapped and trucked to Auckland for installation.

With the main contractor building the core structure, pods were methodically stacked three high and fastened to a steel frame with a structural concrete floor at every third level. The prefabricated construction method provided a range of efficiencies including time and cost savings, improved quality control and simplified on site logistics which meant the programme requirement of installing six pods each day was easily achieved and even accelerated to nine as the project neared completion

Strong and silent

Although the advantages of building each pod off site in a controlled environment were numerous, it also presented some unique challenges. Finding stable and consistent products that could adhere to tight tolerances, meet the strict fire rating and low maintenance criteria were key requirements.

Secura Interior Flooring by James Hardie was installed in each pod and provided a range of advantages. “We wanted a flooring system that was light and easily handled and provided a good stable substrate for carpet tiles and Secura Interior Flooring more than fulfilled that requirement,” says Stanley Group Project Manager James Corric.

“It’s also moisture resistant which meant we didn’t need to use a second substrate in the bathrooms.” A fire rating of one hour and an acoustic performance of STC 55 between inter-tenancy floors was another key requirement that Secura Interior Flooring met.

“We needed a two-way fire rating for the Secura Interior Flooring and the plasterboard ceiling below which was an untested system at the time,” says James. “James Hardie developed the floor system and its details and got them assessed for fire rating by BRANZ which allowed us to use the product.”

The tongue and groove joint means Secura Interior Flooring is compatible with other 19mm flooring products and eliminates the need for timber trimmers along the tongue and groove joint.

“Installation was simple and straightforward,” says James. “James Hardie even supplied the sheets pre-cut to size in the most efficient layout, which eliminated double handling, allowing us to gun nail and glue them straight into position, and minimised waste.