For centuries it has been a staple material in building construction, but why is Oak a superior choice for Roof Trusses?
Initially the wide availability of Oak in the dense woodlands of Britain made it an obvious choice. Large quantities of timber can be produced from just one Oak tree, making it ideal for large building projects.
A lack of manufacturing processes and ability to produce synthetic construction materials left few alternatives. As its use became more widespread, the natural strengths of Oak became apparent and even now few materials can rival its all round suitability.
This has led to Oak acquiring a reputation as a premium building material.
Features of Oak Roof Trusses
Oak is famed for its natural hardness and strength.
As Green Oak Trusses dry over time, this only strengthens the overall Truss. The timber used in the members of the upper chord is subsequently naturally resistant to compression forces.
Likewise, the Oak Beam forming the lower chord is similarly resistant to tension. Combined with the triangular design of the Oak Roof Truss this gives an exceptionally sturdy unit that easily bears cumbersome loads.
Due to the large size of Oak trees, it is easy to source long timbers for the main Truss parts. This avoids the need to combine shorter pieces together, weakening the member at the joins.
Also, Trusses are designed to use the minimum amount of material to support large loads. To support the same amount of weight, a steel truss would weigh ten times as much as one made from Oak.
Oak is one of the most durable temperate hardwoods available. As a result, Oak Trusses can be enjoyed for generations to come.
There are three main factors that can damage and weaken structural timber – pests, water and fire. Oak is naturally resistant to all three.
Immunity to Pests
Due to the presence of high levels of tannins in the wood, Oak is unpalatable or actively toxic to many insect species.
The European climate is also unfavourable to foreign species that could be transported with timber from abroad. Most insect species that feed on Oak will only attack live or freshly sawn timber. By the time the Oak Roof Trusses are built and installed, they will no longer be a viable food source for most species.
Fungus species that affect Oak also prefer live trees and the low moisture content of sawn timber makes it largely immune to attacks.
Oak has a high level of water resistance, making it naturally weatherproof.
Obviously, this is not an issue for internal Oak Roof Trusses as the envelope of the building protects them. For half timbered buildings with exposed end Trusses, Gazebos or Carports, it is a huge advantage.
They will not need to be weatherproofed with messy or toxic chemicals, saving time and money.
Slow Burn Rate
Due to its dense structure, Oak burns slowly, creating a layer of charcoal that insulates the wood beneath. This controls the rate of combustion, allowing time to react.
Softwoods will burn rapidly, spreading the fire and quickly leading to collapse. Even steel will soften and suddenly collapse well before a similar Oak structure is badly affected.
Aesthetics Of Oak Roof Trusses
In buildings with an open roof space or attic conversions, form is just as important as function.
The truss itself forms a part of the decoration of the room Oak has a natural, traditional aesthetic.
Reduced Environmental Impact
Oak trees absorb carbon while alive and when they are felled this is trapped in the timber. Combined with replanting and sustainable forest management, Oak a carbon neutral building material.
Since it’s from nature, there are no harmful manufacturing by-products and is easily recycled. Its natural durability means no chemical treatments are needed for preservation or protection.
Finally, its longevity reduces the need for replacement which means timber isn’t wasted as easily.
Hardwoods Group are specialists in the design and manufacture of oak framed buildings. We offer a range of Oak Roof Trusses or a bespoke design service for individual projects.