StopDigging NZ, the new Ground screw for solid foundations
We recently spoke to Adam from StopDigging NZ, a company that’s changing the way we know foundations in NZ with their Swedish developed concept; the Ground screw for solid foundations. It’s said to be a lot quicker, a lot more economical and a lot less mess than your usual concrete posts. We are using these foundations for our new office on Rangitahi, and thought we’d help you get to know them a bit better, as we were very impressed with their work! (You can check it out in the video below).
Tell us a bit about StopDigging, what do you do?
We design and install groundscrew foundations, for many applications, and have options for full house foundations, cabins & sheds, decking & boardwalks, fencing and signposts, as well as commercial applications like solar panel mounting systems, noise barriers and street furniture. We have a network of region partners around the country and offer nationwide installation.
What’s different about StopDiggings foundation methods?
Our groundscrew system as a whole is designed to be portable, quick and clean. This is generally the opposite of most foundation methods. The lack of ground disturbance and speed of installation means we are also extremely cost effective.
Where did this revolutionary idea come from?
Most people don’t realise that screw piles were first used in the 1840’s for Lighthouse foundations off the east coast of Ireland and North America! Screwpiles are widely used in large commercial construction worldwide (including in NZ) , and this concept was taken by our founding company in Sweden and applied to shallow pile foundations. They realised this was a fast and clean way to create foundations, but that it also offered a superior solution to shallow concrete foundations in areas where frost heave was a problem. We have similar conditions in parts of New Zealand where expansive clay requires a suitably designed alternate foundation. Groundscrews are a perfect option for this, and can also be combined with concrete slab or raft foundations to reduce construction time and costs.
Why use this kind of method?
Simply put, Groundscrews are a superior solution for a shallow pile foundation. They save time, eliminate ground disturbance, waste and the associated site run off and pollution. They are also designed to last longer than a timber pile, and have the advantage of being easily removable and recyclable – they are therefore perfect for temporary applications also.
Is this an Environmentally friendly alternative?
Our ISO9001 certified design / manufacture / distribution and installation process has a lower carbon footprint than concrete for sure. The removal of the need for excavation on site and the associated logistics and mess of transporting fill away and getting concrete in are also eliminated. According to the MBIE there has been an issue in some parts of New Zealand with run off from building sites getting into the stormwater system and affecting the ecosystems in rivers and estuaries – although we are never going to stop using concrete in construction, it makes sense to use an alternative solution where possible!
What can someone expect to pay to use these foundations for a small / average size 3 bedroom house, and how long does it take?
A typical timber subfloor based on NZ3604 has approx 1 pile foundation for every 2 or 3 sq/m of floor space. So perhaps a house of about 120sq/metres would have between 50 and 60 piles in total. On a flat site, with good ground, our groundscrew foundation, including our engineers design and producer statements would be between $10k – $12k +gst.
We work on a simple fixed cost per groundscrew basis that includes installation.
We would have this foundation size installed in just 1 day, and the groundscrews are ready immediately to be built on.
Check out this video of the StopDigging NZ team inserting their Ground screw foundations for the new Rangitahi office! Find out more and get in touch via their website here. Or follow them on instagram for updates on all their projects! @stopdiggingnz