One of the questions we’re asked most frequently by people new to helical piles is why they should consider screw piles over concrete. After all, concrete footings have been the standard in construction since the 19th century, providing buildings with the strong foundations they need to withstand the test of time and the elements. So, why should you consider using screw piles instead?
Well, while screw piles may not have been as widely used as concrete, they’ve actually been used regularly for nearly two centuries And they’ve been deployed in a surprising array of projects. From home offices to houses, sheds to stages and piers to pavilions.
So, in the battle of screw piles vs concrete footing is there a real champion?
Screw Piles vs Concrete Footing: Everything You Need to Know
Concrete
Concrete has become ubiquitous in construction for three main reasons: it is strong, durable, and cost-effective. Its efficacy in the weight distribution of large structures has been proven time after time. That’s why it has become such a mainstay of the construction industry. But it’s not without its faults.
The downsides of working with a concrete footing
· To be effective, concrete footings need to be deep. And this requires serious excavation. This is fine if you have the space to facilitate the use of earthmoving equipment. But if you don’t, the exercise becomes extremely time-consuming.
· And because of all that excavation, installing a concrete footing inevitably generates a lot of waste, which will need to be cleared from the site. Often involving seemingly endless skips or spoil removal with diesel lorries/trucks.
· Moving earth – and the associated vibrations – can also be detrimental to the stability of the surrounding area, including any adjacent buildings and their foundations.
· Concrete is temperamental, and will only set in the right weather conditions.
· A concrete footing won’t work in all environmental conditions and soil types.
· And, of growing concern, is the fact that concrete is one of the most environmentally unfriendly synthetic materials in the world and the cement industry is one of the main producers of carbon dioxide.
Screw piles
The primary appeal of screw piles is that they provide a quick and easy structural foundation solution. It is often the case that no ground excavation is necessary and when some excavation is necessary, it is normally minimal. Screw piles can be installed quickly and in all weather conditions. Where required, they can be installed by hand, with an electric install machine or power pack driven machine. For larger projects, you can deploy a skid steer or an excavator with a screw pile drive unit. The installation of screw piles creates very little disturbance to the surrounding area. In addition, they are load-bearing immediately after installation.
They are also considered to be a greener option, because of their production method, avoidance of concrete, reduced environmental disturbance, reduced water runoff and drainage requirements and the lack of spoil to be removed, in many cases, they are also more cost-effective, when man-hours, work time and spoil removal are factored in.
The downsides of working with screw piles
· Screw piles are not suited to all ground conditions. While they work well in clay and sand, in bedrock, or in other types of ground that contain large obstructions, the use of screw piles is not “usually” advisable, though sometimes pre-drilling can overcome these issues.
· There is a limit to the amount of torque that screw piles can take. So, it’s really important that you understand the load that the screw piles will require before beginning construction. Due diligence is a must with any foundation type, but investigate and plan well, and this won’t be a problem. Employ guesswork, and you can be setting yourself up for trouble.
What is the answer to the great screw piles vs concrete footing debate?
The simple answer is that every project should be taken on a case-by-case basis. The type of structural foundation that is of the most benefit to you will depend on the ground conditions you are working with. Your time frame. The space you are working in. Your budget. Your design philosophy, and the tools you have available.
There are scenarios where one option will always be superior to the other. And there are cases when it will just come down to personal preference. Whichever applies to you, do your research. That way, you won’t go far wrong.
A Final Note – Cheaper isn’t always more desirable
We at UKHelix are encountering more and more clients that could have gone for the cheaper yet less sustainable option of concrete for their foundations but who instead opted for screw piles, in spite of some additional cost. When asked why they often say something to the effect of:
“I am trying to avoid concrete and this is the way I want to see construction go. When and where it’s possible, I want to use products that are more sustainable and less damaging to the environment” If you need advice about finding the right screw piles for your next project, get in touch with UK Helix.
Disclaimer –Information in this blog does not in any way constitute building advice or guidance for private or commercial building projects.
Graham Brown
We would like to discuss the practicalities of using the helix screw system in a commercial application, with a one or two-floor panel build system. The ground is mainly sandstone and we need to consider the chance of seismic activity in the overall area.