You may not have given it much thought before, but roofs are generally made out of one of two materials – either timber or steel. If you were designing a roof for a building you would choose one of those materials, whereas you might choose from a whole range of different construction materials when building other parts of a house.
Historically of course timber was always the structural material of choice, being used for both frame and roof construction for thousands of years, with timber roof trusses having been used in construction since at least the Middle Ages. In fact, you may be surprised to learn that a recent archaeological dig in 2016 showed that a so-called 4,500-year-old “Superhenge” near to the famous landmark Stonehenge was in fact made out of timber posts rather than out of stone. It had previously been believed that a massive stone circle made up of nearly 100 standing stones had been built in Wiltshire, but excavations instead found large pits that once held large timber posts. It is now believed that the “Superhenge” was in fact a large timber circle which may have been made up of as many as 200 timber posts, and that therefore it was a “Timberhenge” rather than a “Stonehenge”.
It might be even more of a surprise when we say that timber trusses are in fact increasing in popularity rather than decreasing, just as timber is becoming increasingly fashionable again as a building material for a wide range of other purposes such as cladding, decking and even roof shingles. You might think that new and better materials had been invented by now that would have replaced timber, but that is not the case, as nothing quite yet matches timber’s structural and thermal performance, cost and appeal. Whilst the manufacturing methods and technology used to create roof trusses might have changed over the centuries, the basic principles behind using timber have not, and the reasons that make timber so great for making roofs with are the same reasons that make it so great to use for other products that also need to perform structurally. Timber has stood the test of time, and in this article, we explain why.
Strength and durability
There are huge benefits to using timber, the first of which is that it is incredibly strong. Timber is made of strands of fibre that can withstand a lot of pressure, which makes it ideal for distributing the weight of the roof away from the walls of the building. This also makes it ideal for footbridges, decking, flooring and anything else where a strong and durable material is required.
Just because wood is strong, that does not mean that it is heavy. It is in fact very light, which is the ideal combination as it can be used to hold the weight of the roof whilst putting the minimum amount of weight possible on to the building itself. Therefore, the strength to weight ratio of timber is phenomenal, and perfect for roof construction.
Flexibility and versatility
Timber is an extremely versatile construction material that can easily be used in conjunction with many other building materials, and for many different types of building. Timber can be easily changed to fit a specific building project, and there are many different types available, meaning that you can find the best type of timber for your specific project. Timber is definitely not a “one size fits all” product, which makes it ideal for so many different uses!
Timber is the only renewable construction material. Think about it – when we use a tree to create timber, we can grow more trees to replace it, whereas there is a finite amount of iron and carbon in the Earth that is used to make steel. Using timber for roofs is therefore better for the environment and better for our long-term ability to be able to continue building roofs for houses, as it should always be readily available if we look after our trees correctly.
Alongside the above benefits of using timber, another huge benefit is the cost. Timber trusses are much cheaper than steel trusses, because you don’t have to manufacture timber, whereas you do have to manufacture steel. Timber roof trusses can also usually be installed without the use of specialist, heavy machinery as they are very light and so can easily be moved into place. They can also be manufactured before being transported to the building site, saving time on the actual building project itself. This all means that the cost of the building project itself is less, and therefore meaning that the house as a whole is more affordable.
Using timber in construction means a smaller carbon footprint than using steel, as a lot less energy is used to create timber roof trusses than is used to create steel roof trusses. The same can be said about timber as a construction material throughout the building – timber has a much smaller carbon footprint than both steel and concrete.
Timber trusses have excellent thermal properties, especially when compared to steel, meaning that the end result – the house – will be much warmer than if the roof was made out of steel.
Another key reason for using timber for roofs is its appearance – timber is a beautiful, natural product and can be used to complement and enhance a beautiful building, whereas steel generally looks quite ugly. Unless you are deliberately going for an industrial look and feel to your building, you are unlikely to want to show off steel trusses but are instead more likely to want to hide them away. With timber, you not only want to show it off, but you can incorporate it into the design of your building, and you have a huge amount of options when it comes to doing so because it is so versatile. It gives gifted architects the opportunity to show off their talents!
You may be surprised to hear this, but when it comes to fire safety, there may be a big advantage to using timber as a construction material rather than steel. If your house is on fire, it may well reach temperatures between 400 and 500 degrees Celsius. At temperatures this high, steel will lose most of its structural integrity, it will bend and melt and the building will collapse, whereas wood (provided it’s been well designed) will char and then burn from the outside to the inside, potentially buying vital time in a house fire.
So, are there any downsides to using timber for roofs? Of course, there are always negatives and no material is perfect. Timber can of course rot or warp, particularly if it is exposed to the elements, and also risks being damaged by woodworm, but this of course can be treated. However, it is generally recognised that the positives of using timber for roofs far outweigh the negatives, which is why timber has been and continues to be the most popular material for roof construction. So many of these positives apply to timber products and uses across the board, which is why we are such strong and passionate advocates of using timber!
Who are EcoChoice?
EcoChoice are specialist suppliers of certified timber products. We were formed in 2005 with the aim of promoting FSC certified hardwoods to the UK construction industry, helping customers to engage in a sustainable way with tropical forests instead of turning away from the deforestation problem. We offer products from a wide range of different timber species, including Ekki, Ipe, Cumaru and Iroko. We are passionate about supplying our clients with independently certified timber products while encouraging responsible and sustainable practices at the source level. To find out how we can help you, please call us on 0345 638 1340, email us on email@example.com or for more information about our sustainable timber products, please visit our website https://www.ecochoice.co.uk/