BY MEG CALKINS, FASLA
Promising new alternatives to tropical hardwoods come with caveats.
FROM THE APRIL 2017 ISSUE OF LANDSCAPE ARCHITECTURE MAGAZINE
The past decade has brought an explosion in the use of tropical hardwood decking and furnishings in public, institutional, and commercial landscapes. Whereas wood decking was once largely the purview of residential landscapes, now it can be found in urban settings from the High Line to West 8?s sculptural Wavedecks. Tropical hardwoods are so durable, hard, and decay-resistant that they appear to be the ideal material, yet the impacts of using even hardwoods certified by the Forest Stewardship Council can be substantial and threaten the most critical ecosystems of our planet.
Wood is a renewable construction material if you compare the amount of time a wood member is in use to the amount of time it takes to grow a tree to yield a comparable piece. But that is not always the case. For example, it takes 90 years to grow a Handroanthus heptaphyllus tree to yield ipe lumber for deck boards, but the deck boards will likely not be in use for 90 years even if they are reclaimed, refinished, and reused. As concern for the health of tropical forests is increasingly recognized in sustainable design thinking, alternatives to tropical hardwoods for decking and site furnishings are making their way into the market. The most promising alternatives are thermally modified lumber, polymerized lumber, acetylated lumber, and black locust lumber...