STEEL: A SUSTAINABLE ALTERNATIVE TO CONCRETE POSTS
Traditionally, concrete has been one of the most popular fence post materials used in the UK, especially when durability is a key requirement. However, from a sustainability perspective, concrete contributes approximately eight percent of global CO2 emissions. Here, John Abernethie, Managing Director at Birkdale, highlights why making the switch to galvanised steel will improve environmental credibility without ever compromising performance.
Production Processes
When assessing the sustainability of concrete, it is important to look at the material’s composition. The crucial component in concrete is cement, which allows the aggregate to bind together to form a suitable building material. Over 4 billion tonnes of cement are used every year and it is the production of this crucial component that produces 8% of global CO2 emissions.
The explanation for this significant contribution to global emissions is that cement production generates CO2 in two different stages. Firstly, the reaction that occurs between limestone and clay to during the production process releases a significant amount of CO2: for every tonne of cement roughly 600kg of CO2 is released. Secondly, to achieve this reaction the raw materials must be heated to over 1,500°C in large rotary kilns. In many cases, this involves the burning of fossil fuels.
Alternatively, galvanised steel has a far less carbon intensive production process. This is because CO2 emissions only occur in order to facilitate its production, the process itself does not produce CO2 as a biproduct. The environmental impact of steel production can also be decreased by incorporating recycled steel into the process. Some manufacturers, such as Birkdale, utilise as much as 50% recycled material into the production of its DuraPost® posts.
This is possible because steel, unlike concrete, can be reused without any degradation of its key properties. The use of scrap steel saves 74% of the energy needed to produce the same amount from virgin materials and reduces air pollution by 86%.
Performance and installation
Concrete is traditionally seen as the best choice if long lasting performance is the priority. However, poorly made or damaged posts are susceptible to freeze-thaw weathering if water ingress freezes and breaks apart the layers of the concrete. If this exposes any internal rebar, these can rust, further compromising the posts’ structural integrity and speeding up the degradation of the concrete.
Steel posts on the other hand offer improved performance. Despite being 80% lighter than a concrete alternative they can resist highspeed winds and will not twist, warp, crack or rot. As a result, at Birkdale we will guarantee its DuraPost® posts for up to 15 years, or 25 years when the steel is polyester powder coated. Consequently, a steel post requires no maintenance throughout its long life.
The improved strength-to-weight ratio of steel also has benefits from an aesthetic perspective. A common complaint about concrete is its bulky and brutalist appearance – steel on the other hand provides a slim, modern alternative that comes in a range of powder coated colours.
This also has a significant benefit for installers, as the reduced weight and bulkiness of steel makes the job far easier to install and means that a greater quantity of posts can be loaded and transported in the back of a van.
End of Life
It’s a sad reality that the construction industry generates 62% of the UK’s waste, 32% of which is sent to landfill. Whilst there are some avenues for recycling concrete, the practice is difficult and not prevalent. The recycling of steel, however, is long-established and facilities dealing with scrap steel are far more common. This greatly simplifies the process and makes it easier for contractors and homeowners to actively engage as part of the circular economy. In addition, the endlessly recyclable nature of steel further facilitates easy reuse without compromising the quality of the end product.
If you are looking for a more sustainable fencing solution, steel represents the ideal choice. It is of course still crucial to partner with an established manufacturer with the relevant certifications. Established in 1982 and certified carbon neutral, Birkdale is committed to providing fencers and landscapers with durable, high-quality solutions that offer a sustainable alternative to traditional fencing methods.
To find out more about Birkdale’s DuraPost® range of steel fence posts, follow the link: www.birkdalesales.com/durapost.
