International Wood International Wood 2017 | Page 26

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with the weight of 60 visitors at one end was just one of the chal-
lenges for Arup, the project engineers. The massive timber structure
is anchored by a large underground box filled with 20 tons of steel
to prevent it from tipping over. The structure is designed to resist
approximately 10 tons of wind loading.
In recent years CLT structures have started to appear in many
urban centers. CLT is affordable, easy to assemble, and fire resistant,
thanks to the way wood chars. What’s more, wood is a renewable
crop and a carbon sink that continues to remove the carbon dioxide
it absorbs during growth even after it’s been harvested and processed
into lumber. IW
PROJECT: The
Smile urban pavilion
Alison Brooks, architect
ENGINEERING BY: Arun
PRODUCT: American Tulipwood
DESIGN BY:
PHOTO
CLT, also known as mass timber, is similar to plywood but with
thicker laminations. It is said to be as strong and fire-resistant as
structural steel or concrete, and it can be manufactured to specified
dimensions. Many engineers refer to CLT as “plywood on steroids.”
This project was made with American tulipwood, known
domestically as yellow poplar, which is a prolific hardwood species
unique to North America. Tulipwood has a subtle grain and there
is a marked difference between the creamy white sapwood and the
heartwood, which can vary from pale yellow or brown to green or
even purple. The wood darkens upon exposure to light. Tulipwood
has extraordinary strength properties relative to its weight, making
it highly suitable for structural applications, such as glue-laminated
beams and CLT. Other species commonly used for CLT include
spruce, larch, stone pine and white fir.
With its colossal curved profile, The Smile looks as though it
could rock from side-to-side. Ensuring that that doesn’t happen even
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PHOTO BY TOM RIDDLE
INTERNATIONAL WOOD