Concrete Vs Steel & Timber

As you look at the infrastructure around you, you will struggle to find a building that doesn’t incorporate concrete somewhere in its design.

Concrete is the most commonly used man-made material on earth and is vital for construction. It is used in hospitals, homes, dams, bridges, roads, airports – everywhere and anywhere! It can be used for everything from structural applications, to paviours, kerbs, pipes and drains.

However, what other materials are available? Wood has been used in construction for thousands of years and is still one of the most widely used building materials, appearing in everything from houses to boats and other shelters, as well as furniture and décor.

Additionally, steel is well-used in today’s civil engineering industry due to its proven high strength and durability.

Certainly, each of these three materials has their advantages, and their advocates. But how do they compare against each other? We’re going to compare each material against a series of criteria, to help you understand the differences, strengths and weaknesses between them.

Concrete

Concrete offers many advantages as a construction material as it is:

• Very durable
• Low maintenance
• Does not rust, rot, or burn
• Wind and water resistant
• Effective soundproofing material
• A local product – raw materials widely available in the UK.
• 100% Recyclable

However, it can be more expensive than other products and is heavy, which may present transportation challenges. It also cannot be stored once it is mixed as the cement reacts with water and the mixture hardens.

Timber

Timber is:

• Light, and easy to work with
• Inexpensive
• A natural resource (so are the raw materials for cement and concrete)
• Beautiful to look at; every tree is different
• Good at absorbing sound inside a building

However, it cannot be easily used to build at height and requires treatments and protection from chemicals that themselves are often manufactured in energy-intensive processes. Timber is also more susceptible to water damage, fire, decay, and termites. It cannot be easily recycled; often less than 50 per cent of a tree is actually usable timber for use. Most timber used in UK construction is imported.

Steel

Finally, steel is:

• Strong and cost effective
• Quick to erect, which can lead to labour savings
• Suitable for prefabrication and mass production
• Reusable after a structure is disassembled
• Easy to repair
• Good for expanding existing structures
• Easily recyclable

Additionally, steel binds well to concrete, meaning reinforced concrete can be used to provide deep foundations and basement, making it a very popular building material.

However steel also has its downsides:

• Made using an energy intensive process which emits significant amounts of CO2 and other GHGs.
• Exposure to the environment can damage the material and cause corrosion
• Susceptible to buckling
• Not fireproof
• High manufacture and maintenance costs
• Most of its raw materials have to be imported if produced in the UK or imported as a finished product.

How Sustainable Are They?

Some people initially consider concrete to be unsustainable as it takes a lot of resources to produce. But this is not the full picture:

• Concrete buildings actually absorb CO2, what is known as recarbonation or the ‘sponge effect’
• Concrete is durable and highly resilient, with a lifespan that is two or three times longer than other common building materials.
• The manufacture of concrete can use a lot of water, however the use of admixtures can reduce the water content by up to 30 litres per cubic metre. The vast majority of ready-mixed concrete already includes water reducing admixtures.
• Concrete absorbs and retains heat very well, which means it will increase energy efficiency of a building and reduce HVAC expenses.
• Concrete produces little waste as it can be produced in batches specific to project needs.
• When a structure is no longer needed, cured concrete waste can be recycled to create new construction materials.
• In particular, CEMEX has made the sustainability of the materials it offers a key priority for its business globally. As part of this:
  • The company has a global target of 35% reduction of CO2 emissions per ton of cementitious products by 2030
  • It is the industry's first company to target a CO2 reduction in its European operations of at least 55% by 2030
  • Already launched in the UK, Vertua®, its first-ever net-zero carbon concrete, will soon be available in its major markets worldwide

Wood is often imagined a natural, sustainable, and environmentally friendly building material. However, deforestation is a major problem, causing soil erosion, water cycle disruption, greenhouse gas emissions, and biodiversity losses with every tree that is felled. It is therefore vital that any wood used in construction is sustainably sourced and any replacement planting is done in a way that ensures eco-system balance and is not a monoculture that has significant negative impacts on natural environments.

Additionally, while wood stores carbon dioxide, any wood used in building needs to be careful maintained long-term; if any building is no longer required, the beams would need to be stored without decomposing or re-used without releasing the CO2 in order to make the carbon equation work

Finally, while steel can contain high percentages of recycled content, the manufacturing process remains one of the most energy intensive industrial sectors.

Which Product Comes Out On Top?

In conclusion, it is clear that each has their own benefits. Timber is light, easy to work with and adaptable, while steel offers speed of use and is durable.

However, when the benefits of each product are analysed, it becomes apparent why concrete is the second most consumed material on the planet (second only to water). It is cost-effective, versatile and typically made from local materials.

It creates durable, resilient and robust buildings which offer considerable safety advantages. Furthermore, the increased focus by manufacturers such as CEMEX on sustainability mean it is a product that can have green benefits alongside practical ones.

The numerous benefits of concrete as a product simply cannot be ignored, which is why it is the favoured building material for many construction projects.