Timber-based systems have been the key factor for Big River and their partners building faster, better and cheaper public housing in Victoria.
Housing is an essential part of life, but in many regions of Australia, large numbers of people are unable to afford to buy or even rent at market rates. In Victoria, the government has responded to the growing number of people who are homeless or at risk of homelessness with its $2.7 billion Homes for Victorians initiative. As a part of this scheme, 68 social housing units are being constructed in Preston, with the first set of 22 underway.
The government brief for this build had very clear-cut requirements regarding sustainability, acoustics and insulation, and wanted the best ‘bang for buck’ result. Building materials supplier Big River Group, and its system partner The Tilling Group, brought a wall and flooring solution that met every need and became the centre of builder SJ Higgins Group’s winning response.
As Ray Ferretti, Big River Group’s national product manager, says, “It was a directive from the DHSS to build in timber but the build also had to meet Green Star requirements, the regular NCC requirements around acoustics and the required fire ratings as well for floor, wall and ceiling. The only way we could do that was by using Tilling’s TecBeam walling and our MaxiFloor product.”
Multiple factors drove the choice behind the systems, but the critical one was soundproofing. “The NCC requirements are very, very stringent for sound transmission through floors where there’s a tenancy above and below, “says Ferretti. “The MaxiFloor product performed very well. We’ve recently completed actual onsite acoustic testing and the early indications are that it exceeds our estimated results and is well above the minimum requirements.”
MaxiFloor is an autoclaved aerated concrete flooring product, available in 75mm and 50mm-thick panels. It has excellent structural, thermal and fire-resistant properties, as well as superior insulation performance – requiring less energy to heat or cool than concrete. Approximately 5000m2 of 1800x600mm panels were used.
“This system outperforms the majority of other systems available on the market,” says Ferretti. “When we’re talking about solidness underfoot, it’s the closest thing you’ll get to a concrete slab without having one.”
Being lightweight, the panels can be lifted into place without special equipment and glued and screwed into place by builders. Any standard floor covering can then go directly on top.
The other system component, Tilling’s TecBeam, is a lightweight steel and timber composite structural I-beam. The innate strength of the LVL and galvanised steel web that make up the beam allows it to function as a structural beam within a floor or roof solution, sustaining loads of 10-15kN, with uniformly spaced service holes. This sturdiness meant that the flooring system could be laid directly on top of the TecBeam walls and joists for a seamless fit.
The relationship between Big River Group and Tilling goes back decades. “The driving factors behind us working with them are their innovation, their quality service and engineering expertise – and also their marketing expertise,” says Ferretti.
Tilling supplies its product to Big River, where it is packaged with the rest of the componentry for a particular project and delivered to the end user. “It means the builder has one major point of contact,” says Ferretti, “which saves them time and effort. And then using timber-based systems means the same builders and carpenters on that job are able to do all the wall framing, the floor systems and roof.
“For this build, they didn’t have to get any wet trades in, they didn’t need concrete form workers, just the same trades were able to work right through that whole project to completion.”
The build time was eight weeks quicker than the schedule for a similar structure in concrete and steel, and came with a considerable cost saving. Unlike many large projects, as this one nears its end it is both on time and under budget, and the main contractors are all still very happy.
“We would absolutely encourage other state governments and local councils to look at this model for their social housing,” Ferretti says. “It’s a friendly building, it’s built in timber and it meets all the NCC requirements for that class of building. What it comes down to is the willingness of the developer or owner or whoever’s funding the build to take that step away from the traditional concrete and steel to a timber-framed building.”
The contemporary finish of the units involves multiple facade materials that are all easily attached to the timber frame. “The building itself is quite innovative,” Ferretti points out with wholly justifiable pride. “It’s cost effective and energy efficient, and has superior acoustics. In many ways, it’s a superior build to much of the private housing on the market.”
Image: MaxiFloor simply glues and screws directly onto the TecBeam, providing a seamless finish. Photo courtesy of Big River Group.