News
Sustainable screw piles will revolutionise the building industry
News
Sustainable screw piles will revolutionise the building industry
A whole new technology is about to revolutionise the way houses are built in Denmark. These are the words of Professor Lars Bo Ibsen from BUILD, Department of the Built Environment at Aalborg University. Along with his colleagues and partners in the companies Andreasen & Hvidbjerg and BAYO.S he has been heading the Innovation Fund project D2D Foundation that has been researching the possibilities in replacing cast foundations with long screw piles.
Sustainable foundations
Dugout foundations made from gravel, sand, and concrete are going to be replaced by steel piles several meters long that are screwed into the carrying layers underground. Th piles make up the foundation that the house rests upon – with load bearing capacity and stability equalling a traditional foundation. Often even better, because soft or moist areas on a site that would normally cause cracks in the construction over time, can easily be reinforced with longer screws, optimizing the load bearing capacity. At the same time, the technology represents a giant leap forward toward more sustainable building.
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When you build a house with a cast foundation you have to start out by digging away the top layer of soil and dispose of it. This takes big machines that emit large amounts of CO2. After that you must prepare the foundation using sand and gravel; resources that are rapidly becoming scarce. Then you cast a concrete footing using cement that is also very heavy on CO2 emissions. All of this can be avoided by using screw piles, and at the same time the building process can be initiated already the day after the foundation has been screwed into the ground instead of having to wait for weeks for the concrete to settle.
Pillar-based houses are climate ready
The screw piles are much gentler on the environment than cast foundations, which means that the new technology can be used to build in areas where you have to take endangered plants and animals into consideration. Screwing piles into the ground with a large screwing machine is much less intrusive than driving around the building site with big trucks and contractor machines.
The result is a house founded on piles in much the same way as pillar-based houses around the world. This also means that houses in areas that in a few years will be exposed to rising sea water levels due to climate change can be raised above the terrain to make them less vulnerable to floodings.
Circular housebuilding
To ensure a high degree of sustainability in the building industry, builders have to get used to think in a more circular manner. This means that building materials must have a much higher degree of reusability – preferably without first having to go through an emission-heavy process of being broken down, crushed, and cleaned. In this regard, screw piles are superior to classical foundations. If a house is going to be rebuilt or torn down, the pillars can simply be unscrewed from the ground, used again somewhere else or smelted into new steel.
Market ready
In the project D2D Foundation, Lars Bo Ibsen and his colleagues have been able to prove that screw piles live up to industry standards, making them fully certified for builders to use in Denmark. This means that a house on screw piles can be ensured on equal terms with any other house.
The first screw pile-based houses are already popping up in Denmark. Televison-host Thomas Uhrskov is using the technology to build a summer house in Klitmøller, and a holiday resort near Rødby is currently building several cottages on screw piles in a wetland among reeds and wildlife.
- Things are moving very fast now. Several of the larger housing companies have adapted the technology. Right now, the main challenge is the demand for the installation machines that can screw the piles into the ground, says Lars Bo Ibsen.
