Tom Barnes of Vastern Timber discusses the many advantages of choosing British timber and takes a look at three areas where Britain leads the way.
It is widely understood that wood is amongst the most sustainable of building materials. The very process of growing trees delivers numerous environmental benefits, and once harvested a tree can be replaced simply by planting another. Once a timber product has reached its end-of-life, it is often reusable by chipping or pulping, and if not, timber is totally biodegradable.
However, it is not always fully appreciated that there are different degrees of sustainability when talking about timber. Issues such as the management of woods and forests, as well as the carbon footprint incurred during transport over long distances all impact on the degree of sustainability contained in a piece of wood. And of course there are the social communities that are either impacted by bad forestry practice, or which are reliant on the timber industry.
By choosing British timber you know that you are choosing the most sustainable option. The UK woodland and forestry industry has excellent standards and in choosing British timber you are helping to support further improvement as well as supporting communities that rely on the timber industries.
Sustainability is not the only advantage to be gained from choosing British timber, especially hardwood.
Oak remains the most iconic of British hardwoods and has been used in construction for centuries. Original oak beams continue to support structures more than 500 years old. The traditional popularity of English oak can largely be explained by the availability of the trees and durability of the wood. As a natural building material, oak is extremely hard to destroy; large sections will resist fires intense enough to melt metal and will flex to accommodate the natural movements of a building.
English oak is considered to be the strongest of the oaks because it has a more interlocking grain than oak from continental Europe, which is characteristically more mild and straight grained.
While imported oak can often be cheaper, there is a sustainability price to pay if the wood is imported. There is also a great deal of difference in design flexibility. Local British sawmills are easy to access, and as well as the option to inspect timber and cuts before choosing, the designer will benefit from more flexibility in cuts from their local sawmill, especially curved and shaped wood.
Of the other native hardwoods, sweet chestnut is proving increasingly popular for external cladding. Vastern Timber recently triumphed at the national Build It Awards, with the company’s Jointed British Sweet Chestnut Cladding securing Best Cladding System. The product delivers the aesthetic of oak, as well as specification choice and environmental benefits. The wood comes from well-managed, sustainable sources and makes for a beautiful and superior cladding system.
British sweet chestnut cladding is hard-wearing, strong and durable, and relatively light when compared to other hardwood cladding, making it ideal for exterior use. Additionally, sweet chestnut is known to be a very stable timber, resulting in less movement, distortion or splitting. It has a similar golden colour to oak, but with stronger grain and occasional dark brown mineral streaks and will weather to a natural silver colouring if left untreated.
Vastern Timber is also a key partner in a team developing the first commercially available thermally modified British timber. Thermal modification involves using intense heat to change the structural properties of wood. The combination of high heat and steam ‘cooks’ the sugars and resins out of the wood, leaving nothing for mould, fungus and bacteria to feed on, resulting in significantly higher levels of durability than non-modified timber. The thermal modification process involves no chemicals and does not rely on impregnating the timber. Unlike most other treatment processes, thermal modification reaches to the core of each piece, rather than simply treating the surface.
Depending on the intended use of the thermally modified hardwoods, both the temperature and the modification period are varied. For external use, where durability is important, the wood is ‘cooked’ at a higher temperature and for a longer period.
The thermal modification process results in products that are significantly more stable than non-modified timbers, meaning they expand and contract less when faced with changes in ambient temperature and humidity, making them a superior solution for a range of uses. Additionally, the superior stability results in significantly less cupping and distortion when used outside. The full modification of thermally modified hardwood allows for cutting and re-working without a loss of performance and without the need for additional treatment.
Through quality and innovation, British timber will continue to be the superior choice, especially for those looking to ensure full sustainability in their designs and projects.