A block of polystyrene foam blown against a window led an Australian company to develop plastic water storage tanks that are sealed in the concrete foundations of new homes.
The ``slab-tank'' system, developed by Melbourne-based Azuratec Pty. Ltd., saves space and water. Azuratec director Dion Bright said the modular system is based on individual tanks blow molded of food-grade polyethylene. The tanks can each hold 66 gallons, and they are connected together with pipes.
The tanks are installed within the concrete slab on which most houses in Australia are built.
Bright said pipes connect the tanks together before traditional reinforcement mesh is positioned over them and the foundation slab poured as usual, sealing the tank system under the concrete floor. Once the roof is on the house, the tank system is connected to downpipes and can start storing water.
The result is a water tank that is out of sight and saves space in the yard, but can still cater to household needs.
Bright said the slab-tank system can also be used under garage floors or driveways.
``The tanks themselves don't take the weight of a car, the concrete does,'' he said. ``So you can use them under a driveway, garage floor or patio.''
Bright said using slab tanks does not diminish the strength of a house's foundations.
``To save on concrete, builders have usually put down blocks of polystyrene foam, know as waffle pods, before pouring a house slab,'' he said. ``We have just substituted tanks for waffle pods.''
Bright's business partner, Steve Cordell, had the idea for the slab-tank system after waking up one night when a waffle pod had blown against his bedroom window.
``Steve had been in the building industry for 20 years and was familiar with using waffle pods in house slabs,'' Bright said.
``After he saw [the loose pod] that night he came up with the concept of using the space taken up by the pods.''
Azuratec was established almost four years ago and started marketing the slab-tank system early in 2008. A major selling point is the versatility of the modular system. Tanks can be big or small.
Bright said Azuratec has received inquiries about the slab-tank system from overseas markets, including North America, the United Kingdom and South Africa, but is currently focusing on the Australian market.
He acknowledged the concept is not complicated and can be reproduced easily. ``It's blow molding plastic. [The tanks] aren't rocket ships, so we would look to export the [intellectual property] through joint ventures or licensing deals.''