Friday, September 6, 2013

BURN, BURN, BURN

Burnt Is The New Black: Why Charred Wood Is So Hot Right Now

By Luke Barley
Architizer


Photos via IC4U.org
The process is fairly simple. Burn the planks on both sides to the desired amount of char. The carbon exterior will release the moisture inside the board as gas and steam. (Think of it as turning the wood’s surface into a chemical compound similar to the pure carbon a diamond.) After cooling the boards, brush and wash them to your aesthetic liking—the amount of char cleaned off changes the look of the wood. Finally, you can seal the board with a natural oil of your choice, or leave it unvarnished.
This method of burning the surface of wood building materials began in Japan during the 1700s. Since Japanese builders traditionally used cedar, as well as cypress, the process is called shou sugi ban, or “burnt cedar.” In more recent years, Japanese have opted for plastic and other materials for their buildings, causing the shou sugi ban to wane.

Shou sugi ban is an organic process allowing for variation. Different values are attainable as exemplified by the floor and fence of this home.
But as passive solar and LEED certification become mainstream architectural concerns, architects are continuing to search for environmentally sound techniques to incorporate into their practices. Using charred wood for construction is a viable eco-friendly option, particularly since this completely natural manufacturing process requires only fire and wood; the harsh chemicals used in pressure-treated lumber are eliminated.
Shou sugi ban also yields an extremely durable building material. Wood treated with fire is paradoxically fire resistant, as well as resistant to insects. The material is also durable due to its low reactivity and is rated to last 80 years.


Shou Sugi BanBYTR Architecten, Maarn, Netherlands
Sunlight changes the visual appearance of this house by BYTER Architecten from black to silver white
Aesthetically the shou sugi ban can look like a dark stain or have a surface texture similar to alligator skin. The finish depends on the extent of the exposure to fire, as well as the amount of char cleaned off after the process. Houses with exterior trim done with the method appear to shimmer, and change from silver to black depending on sunlight.

The renovation of this home replaced the decaying exterior with shou sugi ban. Integrating the home into the surrounding woods and giving it a durable facade.
The downside of using shou sugi ban is the amount of labor needed to produce usable wood. There is also a dearth of purveyors, an example of a lumber mill offering shou sugi ban products is Delta Millworks in Austin, Texas. Finding a contractor well-versed in the use of the material is also challenging. If installing yourself allow extra for mistakes and a learning curve.
The challenges of using shou sugi ban should not deter its use for building. Integrating it into house designs gives not only interesting aesthetic possibilities, but environmental and structural benefits as well.


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