A Bamboo Future
by Carol Steinfeld
January 25, 2001
Super-strong and durable, bamboo is
being used for flooring, paneling, furniture, fencing, engineered
lumber and even structural elements
The super-material of the future may in fact be the largest variety
of grass — bamboo — a traditional construction element
in the Pacific that’s been used almost solely for decor in
the United States.
Now, bamboo is making its way into American homes as flooring,
paneling, stair treads, moulding, furniture, fencing, laminates,
particle board, oriented strand board, engineered lumber and even
structural elements.
Its stability, hardness, flexibility and strength are its most
remarkable qualities, says Steen Ostenson of ReSource Fiber International,
LLC, which sells bamboo flooring, paneling and other laminated
construction materials. “In flooring, hardness translates
to durability. [Bamboo] is 23% harder than oak, 13% harder
than rock maple. It doesn’t dent as readily as hardwoods.
And it’s just beautiful!”
The Wonder Grass
Fast-growing, quick-maturing, hardy, flexible, strong and renewable,
bamboo offers advantages over many conventional building materials.
Its high-density strength — in some ways stronger than steel,
concrete and spruce — is due to its high content of silicates,
essentially the glass-like substance found in sand.
And its reproduction rate is astounding. “Its regeneration
rate is so much better than tree forests,” says California
architect Darrel DeBoer, who designs bamboo buildings. “Bamboo
replaces 30% of its biomass in one year; a tree forest only 3
to 5%.” In fact, bamboo is the fastest-growing woody plant:
Some species can grow up to 3.3 feet a day, and some varieties
(there are more than 1,000) can reach heights of more than 100
feet. Harvesting does not harm the plant, which will produce more
timbers.
And, according to Ostenson, bamboo fibers can be superior to
wood. “It can replace mature fiber every three and a half
years — we’re dealing with a whole different time
cycle. When harvesting soft woods on a 50- to 60-year cycle, what’s
being harvested is juvenile fiber, so you end up with material
that can move around and come apart.” And bamboo offers
more dimensional stability, he says. “It stays in place.
Paneling and Flooring
Bamboo can be increasingly seen on floors and walls. San Francisco-based
Smith & Fong Co. manufactures several products made of “Plyboo,”
their laminated bamboo material, including flooring, paneling, heater
vents, and gift products. Company president Dan Smith says he uses
bamboo imported from China, as well as bamboo from Oregon for some
items. Smith says the most notable advantage of bamboo is its stability:
“It doesn’t expand and shrink. It has twice the stability
of red oak.”
Bamboo is essentially cooked and pressed into shape to make
these products.
Tongue-and-groove Plyboo flooring retails for about $5 per square
foot and is installed and maintained the same as hardwood flooring.
It is available in up to 6-foot lengths. The company’s tambour-style
paneling rolls on to surfaces in 13- x 39-foot sections. It retails
for $5 per square foot.
Flooring is available both finished and unfinished, and in various
lengths, depending on the supplier. ReSource Fiber International’s
products are made with environmentally sensitive adhesives and
are available in 6-foot lengths.
Superior hardness and stability mean that bamboo flooring and
paneling resist moisture and stains, according to Danny Sun of
Bamboo Flooring International in Walnut, CA. “The price
is competitive, and the bamboo knots in the wood give it a unique
look,” he says.
Engineering It
Engineered lumber products may soon follow. Researchers at Queen’s
University in Ontario, as well as B3 of Atlanta, GA, have produced
bamboo particle board to be used as a direct substitute for wood-based
panels in furniture, construction and packaging. ReSource Fiber
is developing a 23,000-acre bamboo plantation in Guatemala, from
which bamboo will be harvested and made into particle board, furniture
and laminated products. “More people will be paying attention
to bamboo for its ability to produce structurally stable oriented
strand board and biomass on a sustainable basis,” Ostenson
predicts.
Andy Lee, a professor of wood products at Clemson University,
reports that bamboo is a viable material for oriented strand board
(OSB), laminated bamboo lumber (LBL) and reinforced material for
southern pine OSB. Laminated bamboo lumber offers superior bending
strength compared to wood-based laminated lumber, however its
elasticity is slightly lower than that of some softwood species.
Bamboo OSB shows excellent strength, stiffness, internal bond
and dimensional stability compared with commercial standards,
Lee says. Bamboo-reinforced OSB beams improve the bending stiffness
of the OSB two-fold, and the bending strength 3.4 times.
One company is considering producing a bamboo truss and joist
product. And bamboo is being explored for its value in composites,
fibers, resins and even telephone poles.
Bamboo Buildings
Bamboo homes are traditional in Asia, the Pacific islands and in
South and Central Americas, but now large-scale buildings made of
whole bamboo are popping up worldwide. In Colombia, architect Simon
Velez has designed one of the world’s largest bamboo structures,
a polo clubhouse. It is one of many of Velez’s bamboo buildings,
ranging from private residences to lodges, some of which feature
roof cantilevers extending as far as 28 feet.
In California and the Southwest, builders of strawbale homes
are increasingly using bamboo superstructure and pinning.
But bamboo houses won’t soon fill mainstream American
subdivisions: “Right now, you’d have a hard time finding
a structural engineer willing to sign off on any sizeable structure
in the U.S.,” says DeBoers, who conducts workshops on building
with bamboo. (An exception, he says, is Hawaii, where bamboo is
plentiful and trees are not.) DeBoer’s bamboo projects are
small buildings that don’t require extensive permits, such
as garden structures and a rest area planned for a zoo in San
Francisco.
As bamboo’s technical construction qualities become better
documented, permitting may become easier. “Bamboo will be
accepted more and more as a building material as building codes
change from prescriptive requirements and proprietary manufactured
systems to performance based, much the way the Pacific Rim operates,”
DeBoer says.
Building with whole bamboo is challenging. For one thing, it
is round; its cylindrical shape requires special joinery considerations.
Bamboo culms (timbers) have size and surface variabilities, as
well as their characteristic segmentation and nodes. Bamboo must
be properly cured and treated for many applications. And most
notably, bamboo is in limited supply in the United States, despite
ideal growing conditions in some regions. Much is imported at
significant expense from China and Vietnam—usually a thick-walled
variety called “Moso,” which is typically 4 to 6 inches
in diameter with very thick walls. The dearth of bamboo in the
U.S. is likely due to the plant’s reputation as an invasive
plant; however, that reputation is changing as growers discover
varieties that grow in clumps that advance slowly and can be controlled.
“It’s a matter of getting enough material and getting
enough education,” says DeBoer. “For now, the thing
to emphasize is using it in places that are really visible, like
flooring and roof structure. Its real strength is in its ability
to span distances and look good.”
How Strong Is It?
Measurements of the strength and construction qualities of bamboo
are becoming increasingly well documented thanks to the work of
Dr. Jules J. A. Janssen in Holland. Janssen’s Bamboo Laboratory
at the Eindhoven University of Technology measures the properties
of bamboo. The laboratory is working to develop grading systems
and building codes for bamboo, just as there are for steel and timber.
The aim is to provide this critical information to engineers, architects
and builders.
Janssen’s research shows that, compared on a mass-per-volume
basis to concrete, steel and wood, bamboo is second to concrete
for strength, and ranks first for stiffness. According to his
book, Building with Bamboo, a short, straight column of bamboo
with a top surface area of 4 square inches can support an 11,000-pound
elephant.
The Bamboo Laboratory also designs bamboo construction programs
for developing countries. In the late 1980s, the lab designed
30 three-bedroom homes for Costa Rica that were constructed from
thick bamboo pole frames covered with a woven mesh of split bamboo
coated with mortar.
In 1992, the homes withstood an earthquake that registered 7.5
on the Richter scale and crumpled all the buildings around them.
As a result, the government of Costa Rica decided to subsidize
the construction of 1,000 bamboo homes annually.
Cleaning Up with Bamboo
Bamboo, which is a voracious consumer of nitrogen, will also soon
be part of an effort to prevent pollution. An ecological engineering
firm in Concord, MA, Sustainable Strategies, has designed a bamboo
plantation system that will essentially eat, drink and transpire
away waste from a North Carolina piggery. Animal waste currently
pollutes both surface and groundwaters, particularly in the South,
choking off waterways and causing diseases such as Pfiesteria. The
firm also employs bamboo in its household graywater garden system,
which diverts water from sewers.
Others are looking at bamboo plantations as a way of sequestering
the carbon dioxide gases that may be causing global warming.
In a land of dwindling wood sources, the potential of super-strong
bamboo can’t be ignored. “The lumber industry is tremendously
subsidized, keeping the price of wood lower than it should be,
and that may change,” DeBoer says. “It’s going
to take some education to do something different, but the results
may well be worth it.”
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