As well as being a historical favourite, timber is increasingly seen as a popular construction material for the future. Timber offers superior insulation, low CO2 emissions and great sustainability when compared to other materials, such as steel and brick.
In this guide, we’ll delve into these advantages and how and why timber has become a favourite construction material.
Timber’s Rise in Popularity
According to research, 70 per cent of all new houses built around the world are now made from timber. In the UK, the figure stands at just 25 per cent, however, we believe this will increase over time as more and more people become convinced of its superiority.
As the government continues in its attempt to combat the housing shortage, it’s looking like timber can provide a way of supplying affordable homes that are cost-effective to live in and can be built in around half the time of a traditional brick-constructed dwelling.
Indeed, countries such as Germany have a long tradition of building in timber, whereas here in the UK, we predominately use brick. However, this is likely to change if we are to follow the trend set by the rest of the EU and here are several compelling reasons why:
Cross Laminated Timber (CLT) is one of the main developments that’s brought timber back in the spotlight. While CLT isn’t going to replace concrete and steel overnight, we believe it has enough qualities to match them and change people’s pre-conceptions of timber in large constructions.
CLT is made of layers of softwood glued and pressed together. From this small timber sections are formed into large structural panels (of around 50cm thick) that are light, stable and comparable in strength to steel and brick. In fact, London architect, Alex de Rijke, describes CLT as ‘the new concrete’.
Prefabricated (prefab) homes are typically made from easy-to-assemble building parts that were manufactured off-site (e.g. in a factory). Manufactured homes and modular homes are both types of prefab housing.
Although often described as something out of an Ikea catalogue, prefab homes are another example of how timber out-performs its rival materials – they’re soundproofed, have low energy heating and insulation and are 50% more energy-efficient than a traditional house.
Making a fully-insulated house shell in a factory has many advantages. It takes a day or two to assemble and a further six-eight weeks to fully kit it out, plumb and wire it – while a traditional home takes 14-16 weeks to build. And since UK builders can’t rely on good British weather either – pre-fab homes can be made in all-weather types (indoors of course!).
One of the great advantages of timber, especially CLT, is its speed of construction. With CLT, the panels are made to measure in the factory, complete with openings for doors and windows. This means that lead-in times are longer – usually 12 weeks from scheme design to the panels arriving on site – but after that, things move pretty quickly.
With pre-fab timber, the time that it takes to construct a house on site is much quicker than traditionally-built houses (standard brick and block construction) – typically it would take around seven-to-ten days, rather than weeks.
Houses with all-masonry walls require a longer period for mortar and plaster on the inside to dry out, so this can extend the build time by several weeks.
Timber frame, by comparison, is a mainly dry construction process. The moisture content of the timber used for the structure has to stabilise after it is weather-tight. Then the walls are usually clad in dry plasterboard to stabilise moisture acclimatisation.
Aside from the effect on drying-out times, weather can also have limitations on how quickly the construction can be built. For example, with brick walls, if the temperature drops below two degrees centigrade, work has to stop as the mortar will not set properly. However, timber frames can be erected in very low temperatures without any adverse effects.
Although costs will vary depending on the scale of a project and where it is sourced, you can generally bet that timber will be lot cheaper than steel-framed buildings, but more expensive than brick. Despite this, timber constructions are far more durable and require less maintenance so costs are saved on the long run.
While it takes longer to work with, steel is stronger and lighter than timber. Its strength means it can cover greater spans than timber and its lightness means it is better suited to sites with difficult access.
However, timber can undertake various treatments to improve its strength. We’ve covered this in a previous blog here, but a good example of this is CLT.
Most modern structures are made in this way and CLT continues to be a popular choice, because it has exceptional strength and stability, which has enabled an increase in high-rise all-timber constructions.
Recently, Swedish architects proposed an all-wood construction – incorporating 240 apartments into four high-rises. This design proves that high-rises aren’t limited to ‘concrete monstrosities’ and that all-timber rises aren’t just environmentally friendly – they’re appealing to the eye too.
Bridport House (Hackney, London) is a great example of a completed CLT high-rise project in the UK. It comprises 41 maisonettes and apartments in two joined blocks – one eight storeys high and the other five storeys.
When it comes to sound insulation, dense, heavy materials have an in-built ability to deaden all types of sound. This is why masonry construction has an advantage over more lightweight timber – because of its dead weight.
However, timber outperforms brick and steel as an external cladding when it comes to thermal efficiency. Typically, a timber wall can be thinner than its masonry equivalent (by 50mm), as the insulation is contained within the depth of the structure.
Timber also has a lower thermal heat transfer than steel, making a timber-framed house cooler in summer and warmer in winter. Basically, a timber-framed house will save you money on energy bills and lessen the building’s impact on the environment via lower energy production.
Timber is highly praised for being environmentally-friendly and a renewable resource, while steel production is one of the biggest polluters.
Because of its low-energy values, it’s looking like timber will have a key role to play as the move towards zero-carbon housing continues.
We think we have a pretty strong argument as to why timber is superior to steel and brick, but what do you think? Will the UK make the switch from traditional brick homes to timber-frame houses?
If you think we’ve missed anything or you’d like to add to the debate, drop us a line on Twitter – we always love to hear your views.
And if you want to know more about the benefits of switching to timber for your projects, or any of the other topics mentioned above, get in touch with International Timber today.