Choosing between steel vs timber construction for a building’s structure involves many considerations. The structure is the core of a building, on which all other components of the building rely. We have outlined the points which we think are most important below to aid you in your decision-making.
Steel Construction Pros
Strength & Stability
Steel is much stronger and more stable than timber, with a higher strength-to-weight ratio. This means that a building requires less steel mass than it does timber to produce the same outcome. It is also what gives steel buildings the capacity to have wider clearspans and larger windows.
The stability that steel provides reduces movement to a minimum. This lack of movement means that it is less likely the building’s plasterboard, or other cladding will crack and move over time with natural contraction and expansion.
Although it may seem unlikely, because steel is an infinitely recyclable product, it has some surprising environmental benefits. The first is that wastage is all but eliminated with its recyclability. Any steel affected by errors in fabrication can be re-used with no loss of material. Additionally, because the elements in steel are readily found in nature, they leave little impact on the environment in which they are used.
Resistant to Fire, Pests, & Moisture
Steel is relatively fire resistant and is not combustible, so will not fuel a fire. There is also no risk of compromise to the structure by animal or insect infestation. And finally, steel does not absorb moisture, which is helpful both during construction and into the building’s lifetime.
Steel Construction Cons
Both the fabrication process and specialised labour required to assemble steel framing increase its cost. Though on the flip side, the lack of wastage and accuracy of production may mean that in the long run, the overall cost evens out in comparison with timber. Furthermore, over larger spans, steel actually becomes more cost-effective.
Although there are environmental benefits to steel, it is also a material that is very energy-intensive to produce. Steel mills are big polluters and leave a high carbon footprint across most stages of the production process.
Steel is susceptible to rust, particularly buildings in marine environments. Hot-dip galvanising steel is one way to offer protection. However, any weaknesses in the steel members from cuts, scratches, or holes will leave the steel susceptible to rust damage if it is carried out after it has been hot-dip galvanised.
Timber Construction Pros
Timber is a natural product and a renewable resource. It also provides benefits to the Earth through CO2 reduction before it is milled. Timber offers natural insulation, which helps to reduce the requirement for heating and cooling; another method for reducing its impact.
Flexible & Familiar
Timber is easily modified if last-minute changes arise on-site. It is a well-known and heavily-used material. Builders are typically very familiar with using timber and can manipulate it as or when required. It has been used in buildings for centuries for a good reason, and no doubt will continue to be used for centuries to come.
Because timber is so widely used, it is an affordable material to purchase. It does not require specialised fabricators, which again keeps costs down. Manufacturing frames off-site speeds up construction, further reducing the corresponding labour costs. However, with large spanned buildings, the costs escalate due to the labour and processing required to get the desired timber sizes.
Timber Construction Cons
Vulnerable to Pests
As a natural material, timber is a target for pests such as ants, borer, and termites. There are treatments available that offer protection, but these incur an additional cost.
Risk of Moisture Damage
Timber is also vulnerable to moisture, which can cause a few different issues. Mould or other fungi are more likely to establish in water-damaged wood. These growths become a health hazard over time. Moisture also results in timber expanding and contracting. This movement often leads to the damage of adjoining building materials, such as plasterboard and other claddings.
Due to its organic nature, timber can be prone to weaknesses through knots and natural defects from the growth of the tree. These weaknesses mean that the clearspan width is often much more limited. If a wide span structure is required, then central posts are likely to be needed, reducing the flexibility of the final space.
Choosing between steel vs timber for the structural core of your building will depend on the factors most important to you. You need to consider the size, purpose, and even location of your project to determine which material ticks the most boxes.
Both materials have inherent strengths and weaknesses, but if you decide that structural steel is the way to go, then get in touch with our team at Tuatara Structures. We use hot-dipped galvanised steel to produce a superior, rust-resistant and robust product. Plus, specialising in structural steel portal framed buildings means we know how to best utilise it to our clients’ advantage.