Some sites simply weren’t meant to be built on. The location could be fabulous. The potential is enormous. But the land itself is beset by problems – from a construction point of view at any rate. It may be a matter of access. It could be the water table level. Although there’s no such thing as a fix-all solution in construction, screw piles can play a role in making some unsuitable sites viable.
How Screw Piles Can Support Construction on Problematic Sites
High groundwater sites
On sites where high groundwater is permanently present, installing foundations can be difficult. Think digging trenches that instantly fill with water. With almost all other foundation styles, excavation is integral. And that simply doesn’t work where a high level of ground water is involved. Screw piles were originally designed to work in water, providing stability for lighthouse construction. Because they can be screwed directly into the ground, reaching down to a stable soil type, they can be used for jetties and piers, as well as other high-water projects.
Flood prone areas
There are all kinds of reasons not to build traditional dwellings in flood prone areas. Both practical and environmental. But in the UK, we’re fast running out of places to build. And there also always seems to be a chronic shortage of houses. Screw piles enable construction to take place in many flood-prone areas. Because they can be fabricated to a range of lengths and widths, screw piles not only enable structures to withstand the rigours of flooding without foundational damage. They allow for the construction of elevated structures. And this means that homes can be built without impacting the flow of flood water. Reducing the strain on the flood plain while still providing much-needed property.
Sandy sites
Sand has never been an easy surface to build on. The load-bearing capacity just isn’t there. But with helical piles reaching down through the substrate to a stronger soil type, building becomes viable once more. With the right width and length of pile, practically any structure can be built upon sandy surfaces.
Poor accessibility
Whether it’s adding an extension in a highly built-up area, or a location down a long dirt track, screw piles have the potential to help. Because of the various installation techniques – by hand, hand-held machine, or a full range of large-scale groundworks vehicles – helical pile installation needn’t be hampered by accessibility. Even where there’s low headroom, such as inside existing structures, there’s the potential to use screw piles. Ensuring that the structure will remain sound far into the future.
Low site disruption
Likewise, when a site is in a built-up area, most foundation types can be highly disruptive. At best annoying the neighbours. At worst, running the risk of disturbing the foundations of existing buildings. Screw pile installation is quick, requires no excavations, and little cleaning up. Minimal dust is created when the piles are screwed into the ground. And nominal vibrations are produced in the process.
Where TPOs are in place
Tree preservation orders (TPOs) almost always mean the need for creativity when it comes to construction. Where a TPO is in place, you are legally obliged to avoid causing any damage to the tree or trees in question. And as excavating will almost certainly cut any tree roots in the area – causing irrevocable damage to the root system – most foundation types simply aren’t suitable. But screw piles can often be installed with minimal impact. They can be positioned to avoid the largest roots. Enabling construction while allowing the tree to thrive. However, it’s important that you check the terms of the TPO before you begin installation.
Root protection areas (RPA) may be more difficult to navigate with screw piles, but they can sometimes provide a solution.
Screw piles aren’t a fix-all solution. They can’t be used everywhere. For example, in solid bedrock they are not a viable option. But in many circumstances, screw piles can help to make previously unsuitable sites viable. So, it’s always worth exploring all of the options.
Find out more about screw pile supplies and services from UK Helix.