Timber iQ Dec 2017 - Jan 2018 // Issue:35 | Page 29

PROJECTS
The exterior of the building with thermally modified American tulipwood cladding.
USING TULIPWOOD
I
According to AHEC, Maggie’s Oldham structure proves that
hardwoods have a role to play in the timber construction
revolution. Previous AHEC projects have all been significant
projects but this centre proves that a building made of
Tulipwood CLT is possible, and that it can be done on a strict
budget and in record time. Like all timbers, tulipwood is a
carbon store. Calculations show that, at the point at which
the tulipwood reaches the factory in Germany where the
CLT is fabricated – after felling, sawing, drying and
transport – it still stores far more CO 2 than was generated
through its processing and transport.
“For AHEC, Maggie’s Oldham is one of the most
important developments in a decade of research and
development into structural timber innovation and one that
could broaden the use of CLT in the construction industry.
The creation of this product and significant use of
hardwood will transform the way architects and engineers
approach timber construction,” says Roderick Wiles, AHEC
director for Africa, Middle East, South Asia and Oceania.
“Tulipwood is particularly useful in structural
applications given its very high strength to weight ratio. In
fact, American tulipwood CLT is around three times
stronger and stiffer in ‘rolling shear’ than its softwood
equivalent and its potential in wood construction is
extremely promising.”
Tulipwood is the fourth most abundant timber in US
hardwood forests and represents 7% of the total growth,
only exceeded by American red oak (18%), white oak (15%)
The building features a thermo-treated American ash decking.
and soft maple (11%). It grows in all 33 states that are home
to US hardwoods and is most abundant in North Carolina,
Virginia and West Virginia.
Tulipwood is under-exploited. Not only is the amount of
growth greater than the level of harvesting in every state,
but the harvest level in all states is less than half of the
growth level. This is partly because tulipwood is a fast-
growing timber and regenerates, not only by natural
reseeding, but also by re-growing from the stumps of
harvested trees.
// DECEMBER 2017 / JANUARY 2018 27