Steel transfers heat and increases heat losses
True – steel transfers a lot more heat than timber in a like for like comparison between the materials. This is not true in a built in wall element though. Why? First of all a light gauge purlin or stud is less than one millimeter thick, i.e. a lot thinner than a timber stud with equal technical properties. In reality in your wall – steel covers less than 1 % of the heat losing area! So what is the rest? Insulation materials – with a lot better thermal properties than timber (or concrete for that matter). So from a wall perspective there is an advantage using steel with a higher grade of insulation in the wall. On top of that we mostly make slots in the profiles in order to reduce the heat loss even more (in fact six times less than solid steel). My conclusion is that if you work with passive houses or other high risk designs you should use steel. It has more advantages than disadvantages when it comes to heat loss, humidity challenges and weight to performance ratio.
Steel is weak in fire performance
True – stee lheated to more than 450 C˚ loses half the load capacity. So why do we make steel buildings at all? Well, first of all steel does not contribute to the fire in itself. So by using other non-combustible materials in your building like mineral wool, gypsum boards and so on, the only thing that will burn is what you have in your building. For example furniture, ware house materials or whatever brought into the building. So when the steel is warmer than 450 degrees, and up to 450 degrees there is actually around 90 % of the load bearing capacity, where are you then? All steel buildings can be made to fulfil the toughest demands, and it’s no coincidence that most high rise buildings have a steel structure or that even concrete is reinforced with steel! Timber burns very well – I enjoy it in my fireplace every winter.
Steel is noisy
Nope – it is not, in fact a building made with light gauge steel walls is more silent than if the walls were made out of timber or concrete. This has been well known for gypsum board manufacturers for many years and this is also the reason why most partition walls are made from light gauge steel and gypsum boards today. Using light gauge steel in an exterior wall makes it possible to build houses near highly trafficked areas with supreme indoor comfort given that you choose equal performing windows, doors and so on. Ok, cutting a steel profile can be more noisy than to cut a timber stud and that brings us to the next subject.
Steel is difficult to cut on site
Yes, you should avoid that – and this can be done by using one of the latest design software which gives not only a nice 3D view for your projects, but also a cutting list and assembly drawings for the installation workers. This means that you can draw and design your project with all electronic information undestroyed all the way to the roll forming! This gives you a real “what you see is what you get” and with the precision of cut to length steel profiles, combined with packing instructions and drawings for on- or offsite assembly this is the future. No cutting! I don’t think anyone works in this with any other materials where most would have to be solved on site as a part of their standard solution.
This was just the short list of all the assumptions people use to tell us why they not work with steel. On top of all the above arguments – steel is the most recycled material in the world. So next time when choosing between timber and steel wouldn’t you rather use some recycled cars than cut down some trees?