kit home foundation

A strong foundation for a kit home built on a sloping site


This charming owner-built kit home, the end product of a knockdown-rebuild project, sits on a solid foundation

Purchasing a block of land with a fire-ravaged home was the foundation of an incredible journey for David and Vicky. Renovating the existing home was out of the question as it would have meant fully gutting it inside at a great cost. Instead, the couple formed a vision of a new way forward. They would demolish the damaged home and build a new one in its place. To save money, they would try to re-use some of the existing footings; also, David would take on the role of owner-builder.

Having carefully formulated a plan, the next step was to choose a kit home design for the site in Mount Kembla, a semi-rural town in NSW’s Illawarra region. “We went to Storybook Designer Homes, selected the design style we liked, let them know what our budget was and then they produced a custom design that suited all of our requirements,” says David.

David’s biggest challenge was his sloping site. Where he wanted to position the home meant that the slope from the front to the rear of the house was going to be over three metres. So, having finalised the home design, the next task was to select a sub-structure that would hold the enormous home. The slope, however, wasn’t the only consideration. While the block sits in a relatively low Bushfire Attack Level [BAL] 19 zones, the area is prone to termite infestation.

David went searching the web with two options in mind: a traditional timber bearer and joist floor or a steel sub-floor system. The main criterion was that the system had to be strong enough to support the loads from the home, given it had multiple roof pitches. He also wanted a strong feel underfoot and a system that would be simple enough to assemble at a height of three metres. After receiving the price for the timber sub-floor, he came across the Spantec website.

“Spantec looked like a professional outfit so I made contact with them. A sales team member gave me a quick rundown on the products and process, after which I went to their office for a meeting, armed with my plans, so we could discuss my build further,” says David.

“The service I received was great. The sales and design teams were very receptive and the steel system on offer was fantastic — and it looked simple to assemble. This was a huge benefit as I was taking on the build myself. Spantec seemed to tick all the boxes but my only concern was cost. To my surprise it actually worked out cheaper and there was less wastage as they cut everything to size. Once we started to build I found the final-stage construction drawings that Spantec prepared really easy to understand. We could not be happier with the result.

” Spantec provided a full supply and construction drawing package. No engineering was required by Spantec, but the team worked closely with David’s appointed project engineer. The project involved three decks and multiple direction floors that required different spans and pier grids. Having a large selection of different-sized bearers and joists within the Spantec Boxspan range proved a huge benefit and allowed the whole floor frame to come together as one complete cost-effective kit.

Adds David, “The materials arrived on-site neatly packed. All the fixing and Ezipier bags were labelled and there was a full set of A3 drawings printed for me in a bag. All bearers and joists were cut to size and each piece was labelled so it related back to the construction drawings. Due to there being a lot of different sizes within the floor system, the labelling made sorting extremely easy.“

A huge saving in the installation was Spantec’s unique bearer punching. Because the bearers and joists are in the same alignment, Spantec has a smart bearer as part of its kit system. At 450mm joist centres the bracket location holes are pre-punched and each bearer carries clear, printed identification as to how it is assembled.”

Spantec pioneered steel flooring systems in Australia and, for the past 29 years, has been designing and manufacturing galvanised steel floor kits, as well as deck kits. These sturdy flooring systems are lightweight, long-spanning, straight and true to size. Manufacturing tolerances are perfect, products are cut to size so there is no wastage, and the systems are easy to assemble.

In addition to manufacturing the Boxspan and Ezipier brands, Spantec offers a design service, an engineering certification service and can produce site construction drawings. Given its extensive experience and expertise, Spantec can provide building solutions for a wide range of projects, including tricky sites such as sloping blocks or lots in bushfire-prone areas. The company is based in NSW’s Southern Highlands but products are available state-wide.

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