Following on from a succesful first phase, the BRE team will now look at ways of refining the process and constructing inside-out beams longer than a single stem. It will also produce indicative working stresses and identify markets for the product.
Small hardwood thinnings normally go for firewood or pulp, but successful development of the beams could add value to a fairly low value resource.
And with the recovery in timber prices – up by around 13% in the year to March, according to Forestry Commission figures – the beams should prove attractive to the joinery and construction markets.
The new project will focus on oak, although other hardwoods are being assessed. Green gluing technology will be used to convert small diameter stems into usable sections of various dimensions by cutting them into four equal quarters, turning them inside out, then bonding and drying them.
“At the beginning of the initial project there was a certain amount of scepticism about whether the concept of bonding small diameter oak and other hardwood stems inside out in the green state would be achievable,” said Geoff Cooper, senior consultant at BRE.
Results to date show that re-engineered beams are stronger and stiffer than solid oak beams processed from similar dimension material and are comparable in strength and stiffness to solid beams processed from large diameter material.
