The development of
"Conventional" American building elements
made from bamboo
Floris Keverling Buisman, Msc

Common Ground Community/Blue Moon Grantee
505 Eighth Ave, 15th Floor
New York, NY 10018
Phone:
+1 212 389 9364
Fax:
+1 212 389 9312

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ABSTRACT
Bamboo, the fast growing grass it is, combined with its wood resembling
properties, has large potential to contribute to a more sustainable
construction industry and world. It not only has the potential to reduce the
footprint that construction leaves on our environment, it also has the ability
to become a sustainable income generator all over the world. Not only for
farmers, but the whole local economy can profit from it.
In this research, distinct factors were studied in order to explore possible
approaches to the development of this abundant natural resource. The
factors were:
•
•
•
•

Marketing factors for bamboo based product in the USA
To improve bamboo’s material performance by using sustainable
technologies
The introduction of improved designs to create functional products
with a wide market potential.
Scope of market for building materials and their price range.

Exploration of these factors led to the development of several possible
construction element/modules that have a synergize bamboo fast growing
aspects, can be produced locally in China and won’t require construction
practices in the USA to change their customs to drastically. Implicating that
the bamboo products will both bring income to the producing county, as
well will be easily implemented in the conventional building industry in the
USA.
Taking all the factors together, the hybrid level (combination of elements of
traditional processes with elements of advanced treatments, non-traditional
processes and the design input) of technology should result in a win –win
situation. Generating more local benefits in China while providing the USA
with a better-engineered and more sustainable construction product.
To introduce these materials on the USA market, various tests will have to
be done on the different materials, so that they conform to the required
standards as demand by the (local) building codes.
The end result of this research is a recommendation of which bamboo based
materials (studs, in- and exterior panels and doors) will be feasible to be
introduced in the USA.

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Table of Contents

Abstract
Table of Contents

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1. Introduction
2. USA Bamboo marketing factors
2.1. Sustainability
2.2. LEED certification
2.2.1. Materials & Resources
2.2.2. Indoor environmental quality
2.3. Raw material physics
2.4. Engineered material physics
2.4.1. The adhesives
2.4.2. Plantations
3. Bamboo construction materials
3.1. Dimensional lumber replacement
3.2. Studs
3.2.1. Wood
3.2.2. Steel
3.2.3. U-shaped bamboo stud walls
3.2.4. Columns & beams
3.2.5. Conclusions
3.3. Engineered wooden products
3.3.1. Glulam beams
3.3.2. I-joists
3.3.3. Trusses
3.4. Panels
3.4.1. Exterior panels

3.4.2. Interior panels
3.4.3. Bamboo sandwich panels
3.4.4. Doors
3.5. Conclusions
4. US market for industrial bamboo construction products
4.1. Demand and prices of wood based products
4.1.1. Studs
4.1.2. Glulams
4.1.3. I-joists
4.2. Exterior panels
4.3. Interior panels
4.4. Doors
4.5. Conclusions
5. Marketing opportunities
6. Literature

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1.


INTRODUCTION

Introducing bamboo construction materials in the USA, has to overcome one
big hurdle: the conventional western building tradition. This grid-lock which
is formed by design customs (architects), building codes (officials and
legislation) and the building industry (manufacturers, suppliers and
contractors) make introducing new and more sustainable products a
challenge. To overcome this problem, the products will either have to have
an aesthetic or practical appeal and to ‘break the ice’ have a sustainable
appeal, which preferably can be combined with the crucial aspect:
competitive pricing.
This implies the following (D. Larasati, 2003):“Although these (sic: products)
are promising, there have been no other official test results on bamboo
board’s endurance against weather, fire and chemical substances. Bamboo
board is commonly used only for indoor construction, therefore the many
other obvious possibilities, such as cabinetry and furniture applications
need to be explored.
This is where designers can contribute their knowledge. Industrial design is
one of the professions, or knowledge fields, that can be expected to uncover
the potential for more creative applications. People in urban areas, who
responded to the questionnaire concerning attitudes toward bamboo
products, welcomed the idea of improved bamboo products and expected
that an exploration of bamboo would lead to new high quality products.
Design professionals can be expected to come up with creative, intelligent
and appropriate uses of the material. With modern applications that can
expose its superior qualities, bamboo material will be able to perform
efficiently and prove itself as a competent and exciting material.”
What qualities and potentials of bamboo that can be merged into a
successful material, for which there is demand in the USA construction

market? This paper first explores the US marketing factors for bamboo in
general. Followed by a research of the production process of ‘western’
bamboo products and which improvements can be made for the US market.
After which common building materials of the USA construction market will
be identified, for which (potential) designs will be identified of their bamboo
based counter parts. The market potential of these will then be determined
in the next chapter, by looking at the prices of conventional building
products, with which it will have to compete and this will help to set the
(target-) price for the bamboo based product. Influencing the market
potential on a different level are sustainability, the building codes to be
met/the costs of testing and if applicable aesthetics.

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2.

USA BAMBOO MARKETING FACTORS

Why would there be a demand for bamboo product in the USA? What would
be the interest of architects and owners, to have this un-conventional
material in their projects, houses and offices? An easy answer could be, the
looks. If the aesthetics are appealing to professionals in the design industry
and/or the people that have purchasing power (owners); the product will get
sold. So making a modern/wanted product is one method to market a
visible building product in the construction industry. The cost and other
influences are in that case of secondary concern. As one can see with Plyboo,
(see figure 1 and 2) which is used in luxury cabinetry and furniture in the
USA.


Figure 1 Plyboo production direction of slits (www.plyboo.com)

The refined properties of this material, the attractive edge and its wood-like
handling, offer carpenters options for intrinsic connections/details (see
figure 2).

Figure 2 Hybrid bamboo miter joint (RISDviews – Fall 2005)

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The appearance of this material initially has a familiar wood feel to it. But
up close it is distinctively different (see figure 3). This grain like appearance
is in general considered attractive and can thus can be left visible under a
protective clear-coat (paint), protecting it from scratches and preserving the
aesthetic value of this natural product.

Figure 3 Front and side of vertical core cross laminate

The high-end look and marketing in that field has had its financial
implications for this product. The consumer cost of this material is
presently $180 per 4’x8’x3/4’ sheet (1220x2440x18mm), which is high
when compared to high-quality birch plywood ($75). The reason the product
sells must be that it has ‘extra’ qualities that plywood doesn’t have. What
are these other factors, besides aesthetics, that makes bamboo so attractive,
exclusive and thus expensive?
After investigating and getting a price quote from FUSTAR, it seems that
prices of Bamboo panels shouldn’t be more $50. This is a wholesale price
but a 300% mark-up for shipping, storage and profit margins from the USA
Bamboo panel importers raises the price to far to be competative. Ways

improve price competitiveness with high end plywood is either direct sales
(over the internet) by the Chinese bamboo manufacturers or using the
economy of scale and the free market (as has worked tremendously for
bamboo flooring that is now less expensive (as a result demand is growing)
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than hardwood in the USA). Meaning that if more bamboo panel importcompanies will compete for the consumers, based on quality and price, the
price will go down and quality will be assured. At the moment there is only
one company importing bamboo panels to the USA, enabling them to
artificially keep the prices high as there is no competition.
2.1.

Sustainability

In the building industry, the selection of a building material is mainly
determined by its costs and durability. However, as sustainability is
emerging as a key issue in the last decade, especially in western countries,
the environmental aspects of building materials have also become a
significant selection criterion. Bamboo, as a fast growing renewable material
with a simple production process, is expected to be a sustainable alternative
for more traditional materials like concrete, steel and timber. (P.van der Lugt,
2004)

Sustainable development is the most vibrant and powerful force to impact
the building design and construction field in more than a decade.
(www.usgbc.org dec 2004). The sustainable properties that are listed above
are reasons that demand for bamboo flooring and other bamboo based
products is growing since the public is becoming more aware of ‘green’
architecture and thus the demand for ‘green’ construction products is rising.

Bamboo can thus being market as sustainable, but as P. van der Lugt’s
(2004) states: Life-cycle-assessment study shows, one has to be careful to
call bamboo sustainable because it grows so fast. One also has to take into
consideration the production process and transportation of the product that
can have a large ecological impact and thus diminish the advantageous
aspects of bamboos rapid growth.
Compared to wood, bamboo can have certain advantages: The amount of
wood required for construction purposes is taxing the regenerative
capabilities of this resource, as well as depleting a critical component in
ecological balance. Trees affect water quality, rainfall, and air quality, both
in the immediate region and on a global scale.
The principles of sustainability, which underpins the Green Builder Program
favors, forest management practices that retain natural forest ecosystems.
Some of the options associated with this approach are difficult to implement.
There are very few "certified" sustainably managed wood sources and
certifying groups are still in the process of determining universal guidelines
for certification (www.greenbuilder.com, dec 2004). One can conclude that
bamboo from well managed plantation can have the competitive edge over
wood. First it has faster regenerative properties than wood and secondly
could fill the void of the lack of certified wood.

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2.2.

LEED certification

“The LEEDv2.1 (Leadership in Energy and Environmental Design) Green
Building Rating System® is a voluntary, consensus-based national standard

for developing high-performance, sustainable buildings” (www.usgbc.com,
2005). Point are given in 6 catergories; sustainable sites, water efficiency,
energy & atmosphere, materials & resources (M&R), indoor environmental
quality (IEQ) and innovation & design process. A total of 69 different credits
can be achieved. A minimum score of 26 points, will get a building a bronze
certification. Bamboo based construction materials can help the
design/building attain credits in the M&R and IEQ categories.
2.2.1. Materials & resources
“Rapidly Renewable Materials
Intent: Reduce the use and depletion of finite raw materials and long-cycle
renewable materials by replacing them with rapidly renewable materials.
Requirements: Use rapidly renewable building materials and products
(made from plants that are typically harvested within a ten-year cycle or
shorter) for 5% of the total value of all building materials and products used
in the project. “ (Green Building Rating System, LEED v 2.1, USGBC 2003)
2.2.2. Indoor environmental quality
“Low-Emitting Materials: Composite Wood
Intent
Reduce the quantity of indoor air contaminants that are odorous, potentially
irritating and/or harmful to the comfort and well-being of installers and
occupants.
Requirements
Composite wood and agrifiber products must contain no added ureaformaldehyde resins.” (Green Building Rating System, LEED v 2.1, USGBC
2003)
See paragraph 2.4.1

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2.3.


Raw material physics

For the most part, the bamboo culm is valued for the solid (wood like)
material obtained from the lower part of the plant, and the jointed stems
that give the plant its distinctive segmented appearance (see figure 4)

Figure 4 Parking Garage in Germany (www…..)

It is supremely strong, durable, stable, and flexible. Certain species of
bamboo possess a tensile strength (or resistance to lengthwise stretching)
that's stronger than steel. In addition, bamboo has a hardness comparable
to maple wood yet is more far more stable-bamboo materials typically
experience half as much contraction and expansion as hardwoods. Bamboo
is also one of the fastest growing plants on earth.

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Figure 5 The bamboo culm as a finishing material (Hulshof architects)
From an environmental perspective, the benefits of bamboo don't stop with
its almost instant renewability. There are a host of other factors that make
bamboo an ideal raw material in a sustainable world. Because bamboo is a
grass, it grows from the base up. Unlike trees, which grow from their tops
and therefore die at harvest, bamboo isn't killed when it's cut. Instead, new
sections simply grow up from whatever portion is left, and a living root
system remains between harvests to hold soils together, prevent erosion,
and stop rain run-off. (www.gaiam.com dec 2004)

Figure 6 Bamboo used as an exterior finishing material in a Parking Garage in Germany


“The main concern of any actual or potential user of a bamboo house or
product is the short durability of the material. The service life of bamboo is
generally considered as being too short for any worthwhile investment. This,
unfortunately, is true to a large extent. Bamboo has less natural durability
than most woods, owing to a shortage of certain chemicals that occur in
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most woods but are absent in bamboo.”(J.J.A. Janssen 2000) This implies
that treatment of some kind is needed to make bamboo durable to western
standards. But if a large market penetration of bamboo product is sought,
one would have to produce product that can be integrated in modern
western construction typologies and not just as a finishing, exotic material
(see figure 5 and 6)
2.4.

Engineered Material physics

“In Europe and elsewhere some people do buy products made in developing
countries, but this can never amount to structural support for the economy
of bamboo-growing countries. For that, there has to be bamboo products
that can compete with products made from wood or even plastic.”(J.J.A.
Janssen 2000). Implying that not the culm, a product based on the culm
(like traditional bamboo furniture) but a manufactured product made from
the culm, is the way to create an increase in demand in Western countries
and generate income/create jobs for the population in bamboo-growing
nations.
The USA construction industry has a high adversity to new building
materials, as change introduces uncertainties and unwanted risks that

most architects and contractors rather avoid than encounter. The materials
design should reflect this, meaning that the products will have to have large
similarities to conventional building products. Again, these bamboo-based
products can take advantage of the growing demand for ‘green’ architecture.
The obstacle of a new, unknown product can be negated. Presently,
sustainability is a rapidly growing influence in the American construction
industry. This can been seen by the number of LEED registered projects,
that grew 400% from 2003 to 2004 (www.edcmag.com, 2005). So, in at this
time, when demand for sustainable architecture (and materials) is growing
among clients the principle “the customer is always right”, will hold through.
This means bamboo products should take full advantage of their
sustainable marketability. One can even increase bamboos given ‘green’
characteristics (rapid renerability), with appropriate manufacturing
practices, as is described in the following paragraphs.
2.4.1. The adhesives.
The adhesive employed to create the laminated products are all resins that
will bond the strips together. Some of these solutions have better waterresistant properties, others have higher VOC emitting properties. The
distinction between the formaldehydes (PF and UF), which is toxic under
certain conditions and the Soy bean based (green) adhesives will now be
further explained, and why this is a concern while introducing materials
with these resins on the USA market.
Formaldehyde

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Formaldehyde is an important industrial chemical used to make other
chemicals, building materials, and household products. It is one of the large
family of chemical compounds called volatile organic compounds or 'VOCs'.
The term volatile means that the compounds vaporize, that is, become a gas,

at normal room temperatures. Formaldehyde serves many purposes in
products. It is used in pressed wood products, especially those containing
urea-formaldehyde glues, are a source of formaldehyde. These products
include particleboard used in flooring underlayment, shelves, cabinets, and
furniture; plywood wall panels, and medium density fiberboard used in
drawers, cabinets and furniture. When the surfaces and edges of these
products are unlaminated or uncoated they have the potential to release
more formaldehyde. Manufacturers have reduced formaldehyde emissions
from pressed wood products by 80-90% from the levels of the early 1980's.
Formaldehyde is a colorless, strong-smelling gas. When present in the air at
levels above 0.1 ppm (parts in a million parts of air), it can cause watery
eyes, burning sensations in the eyes, nose and throat, nausea, coughing,
chest tightness, wheezing, skin rashes, and allergic reactions. It has also
been observed to cause cancer in scientific studies using laboratory animals
and may cause cancer in humans. Typical exposures to humans are much
lower; thus an risk of causing cancer is believed to be small at the level at
which humans are exposed.(www.epa.gov, dec 2004)
Urea-formaldehyde (UF) resins are found in wood products that are
intended for indoor use. Phenol-formaldehyde (PF) resins are used in
products intended for exterior uses. UF resins emit significantly more
formaldehyde gas than PF resins. (www.environet.com dec 2004)
PF also changes the appearance of natural bamboo by making it reddish
and giving it a characteristic smell. (Larasati, 200X) This cannot be judged
as a bad aspect of this adhesive, although this is an important
characteristic which has to be considered for marketing purposes.

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Soybean based adhesives

Environmental concerns and requests from users for adhesives made from
renewable feedstock have caused a resurgence of interest in developing new
soy-based products for the wood adhesives industry.
Air emissions of volatile organic compounds and hazardous air pollutants
contribute to a variety of modern maladies from smog to sick building
syndrome. Formaldehyde and phenol based resins have been targeted for
replacement. The use of soy additives is demonstrating the ability to
stabilize or even reduce total emissions of these pollutants from wood
products.
Most USB-sponsored research has concentrated on the use of hydrolyzed
soy protein (soy hydrolyzate), used either as a direct substitute or in a
mixture with PF and UF. Soy hydrolyzate is made from soy isolate at a yield
of 12 pounds/bushel of isolate. Other research has investigated the use of a
lower-cost soy flour at a yield of 39 pounds/bushel of flour. This product, in
combination with MDI, has been successfully used to make OSB in early
trials. A two-part system of soy hydrolyzate and PRF adhesive has been
commercialized. The PRF/Soy 2000 adhesive system is a hydrolyzate-based,
finger-joint adhesive intended for uses requiring either a nonstructural or
structural, wet-use, exterior-exposure end joint. The adhesive was developed
with funding provided by USB and specifically allows green lumber to be
finger jointed. Typical adhesives in use today can only bond wood that is dry.
(….)PRF/Soy 2000 is accepted by the Western Wood Products Association
(WWPA) as an exterior-type adhesive meeting the requirements of ASTM
D2559, or equivalent. The adhesive is suitable for the bonding of wood
including finger-jointed lumber of all structural grades.
Air emissions of volatile organic compounds (VOCs) and hazardous air
pollutants (HAPs) contribute to a variety of modern maladies, from smog to
the sick building syndrome. Formaldehyde, a major constituent of many
wood adhesives today, and phenol resins have been especially targeted. The
use of soy adhesives may not replace these compounds completely, but

instead allow continued growth in wood product manufacturing to meet
growing world demand, while stabilizing or even reducing total emissions of
air pollutants. (www.unitedsoybean.org dec 2004)

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Relative Economics/Supplies of adhesives
Phenol and urea wood adhesive pricing and availability are both subject to
the vagaries of the petrochemical industry. Phenol demand is driven by
bisphenol A(used for polycarbonate plastics) andcaprolactum (for nylon 6
used in carpeting). Phenol capacity is expected to become very tight as
demand in these areas grows. UF is derived from natural gas, with only
about 5 percent of capacity going into adhesives. Agricultural uses for
fertilizer and feed additives utilize more than 90 percent of U.S. urea
capacity. Urea prices fluctuate significantly with agricultural demand, and
supplies are seasonally tight. Formaldehyde pricing is dependent on
methanol supply and demand. Methanol prices were relatively stable for a
number of years before spiking in 1994. Soy adhesives, in contrast, are
based on a renewable resource. Soy prices fluctuate with world supplies of
feed grains and oilseeds. (www.unitedsoybean.org dec 2004)
PF resins are more expensive than UF, but the VOC emissions of UF are not
a positive marketing tool if one wants to introduce bamboo based product
on the market as ‘green’. It will have to be investigated what the cost (and
other) implications are, if any, if soybean based adhesive will replace (part
of) the formaldehyde adhesives. This so that a ‘greener’ product can be
introduced on the USA market.
“Precious Bamboo® also import glue from Japan which is totally free from
formaldehyde emission and special for Japanese market. After stringent
testing by MLIT, Precious Bamboo® Flooring has been approved of

marketing in Japan by Ministry Approval.” (www.presiousbamboo.com
2005). Research in 2005, while directly approaching this company, has
proven that these non-VOC emitting bamboo floors, are not higher than
‘regular’ bamboo floors ($17.87/m2 or $1.66 SF, CIF New York). The type of
adhesive that is used (imported from Japan according to Precious) is
unknown.
2.4.2. Plantations
Bamboo’s green outlook can be further enhanced by sustainable managing
the plantations. As there is not certification for bamboo yet, as there is for
sustainable grown wood (FSC), the customer has to rely on the plantations
good intentions for this aspect.
“The Forest Stewardship Council (FSC) is an independent, not for profit,
non-government (….), that provides standard setting, trademark
assurance and accreditation services for companies and organisations
interested in responsible forestry.
ounded in 1993, FSCs mission is to promote environmentally appropriate,
socially beneficial and economically viable management of the worlds
forests (…).
The distinctive FSC trademark - the check and tree symbol - as well as

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the letters FSC and words 'Forest Stewardship Council' enable customers
to recognize responsible forestry products in stores around the world.
Major retailers in Europe, North America, South America and Asia ask
for FSC certification when ordering forest products so they can assure
their customers about the origin of the products they are buying.”
(www.fsc.org dec 2004)
As similar certification for bamboo, by an non-partisan, independent


organization, assuring customers that the management of the plantation
resembles a balanced ecosystem, will be beneficial for the local populations,
global ecology and marketability of bamboo. Since certified wood can earn a
LEED credits, if there would be a bamboo certification this would,
presumably, count towards the same credit.

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3.

BAMBOO CONSTRUCTION MATERIALS

The majority of houses in the USA, some industrial construction and mostly
all interior partitions are made with stud walls. Invented in 1833: “Partially
a result of the incipient industrialization occurring in the young nation, the
balloon frame was based on much lighter precut two-by-four-inch studs
positioned sixteen inches apart and held together by factory-produced nails.
Although light, the frame was very strong and able to withstand heavy
winds, since the stress was spread over a large number of studs. The factory
production of nails and mill cutting of standardized lumber reduced costs
and increased availability of materials to individual builders. These houses
were constructed quickly and easily, requiring only two workers using basic
carpentry techniques. The method allowed many urban workers in America
to build their own homes, in contrast to Europe where traditional
construction techniques kept the rates of homeownership low for most of
the nineteenth century.(…..) Balloon-frame construction has persisted, with
most homes today, whether stucco, wood, stone, or brick (exterior,sic),
based on this method (college.hmco.com, dec 2004)

The balloon/stud frame house could be a starting point of this investigation.
Beside studs, beams and rafters in this construction typology, also the
interior sheathing and exterior bracing could be replaced by a bamboo
based product (paragraph 0). The next opportunity is the exterior
sheathing/wall, of which the possibilities are described in 0. After which
possibilities for more engineered wood based product are then investigated
the same paragraph. Of course there are more building components that
can be made from bamboo, which are listed in 0. The overall practical
question in this chapter was: What bamboo materials could be designed,
that could replace these materials and have the most practical and
sustainable properties, so that the substantial and expanding USA
construction market can be effectively penetrated?
3.1.

Dimensional lumber replacement

“Dimensional lumber refers to the wood used in constructing the wall, floor
and roof framing of a house” (www.greenbuilder.com, dec 2004) or any
building. The dimensions that the wood and metal elements are produced in
are essentially the standard components that all contractors and architects
use. The professions are so familiar with these sizes (in wood and steel) that
all new products introduced on the market will have to conform to them
(note: Europe has a slightly different set of standard sizes). In Figure 7 these
sizes are listed, the nominal size is the common name, followed by actual
size in inches and in MM.

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Nominal sizes


2x2
2x3
2x4
2x6
2x8
2x10
2x12
4x4
4x6
6x6

Actual sizes

1-1/2x1-1/2
1-1/2x2-1/2
1-1/2x3-1/2
1-1/2x5-1/2
1-1/2x7-1/4
1-1/2x9-1/4
1-1/2x11-1/4
3-1/2x3-1/2
3-1/2x5-1/2
5-1/2x5-1/2

Size in MM

38x38
38x63
38x89

38x140
38x184
38x235
38x286
89x89
89x140
140x140

Figure 7 Size of dimensional wood in the USA
As stick (or balloon-/metal-) framing is the most common construction
method in the USA, introducing bamboo product that can replace the
common product (a 2x4), could create an enormous market potential.
Bamboo could potentially be the base material for both studs, beams and
rafters.
3.2.

Studs

The enormous market of 2x4 (and 2x6) wood/metal studs is focus of this
investigation. What properties does the product have to have to be
successfully introduced in the USA? And how those properties can be
optimized in the design. This research is based on an investigation that
looks both at copying wood and steel studs. Their properties, means and
methods of construction etc. after which will be concluded what the most
promising is.
3.2.1. Wood
As mentioned earlier in this chapter, the wooden 2x4 is the most common
wood size, and is used extensively for both structural walls (of homes and
low rise buildings) as for interiors (homes and offices). What would be the
options to replace this material with a solid bamboo stud (SBS)?

The first thought that comes to mind is making a SBSs from strips of
bamboo (similar to plyboo construction). One opportunity could be, to be
competitive with pine (which is grown and dried so rapidly, to keep costs
down, that it warps), to ensure the solid bamboo stud is straight, As it is
mechanically produced, this shouldn’t be a big problem. This would give it
an competitive edge over pine wood.
Other considerations would then be:
•

The use and construction would be exactly similar to wood. A concern
here is that the studs are generally nailed together with a nail-gun.

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•
•

The brute force will most likely to split the SBS (as that it is one of its
properties), which will ruin the connection.
Costs (as with plyboo) probably the material won’t be cost competitive
with pine (cost in chapter 4).
Costly aesthetically pleasing material will be hidden in wall

The density (www.simetric.co.uk) of pine wood is around 530 kg/m3 (34
lbs/cf), bamboo is lighter around 300-400 kg/m3 (18-26 34 lbs/cf). This is
before processing, which will add substantial weight. One can make the
assumption that the addition of glue and pressing the material will weigh
down the material to 600 kg/m3 (38 lbs/cf) (P.van der Lugt, 2003). Making
the bamboo studs 1.2 times heavier than the regularly used pine wood. SBS

being 20% heavier is a mayor disadvantage, which will seriously limit the
market potential for this product, while most wood is hand carried on the
construction site before installation this will material will put a bigger strain
on the labor force (and transportation costs). Also, since the overall
construction will be heavier, this will lead to certain structural ‘upgrades’,
that will drive up the costs of the construction. As this construction market
is highly competitive on price, both these factors are really unfavorable
towards solid bamboo stud development.
One can conclude that the hardness, its splitting properties when nailed, in
combination with its greater density are such unfavorable properties, that it
is not likely that the sustainable properties will offset this. If there are ways
to use the higher (softer/lighter) parts of the culm to produce these solid
studs, that don’t have these disadvantages and could be nailed. Such a SBS
product will have potential to be successfully introduced in the US.
Certainly because the construction trades don’t have to learn new
construction methods. Present production process don’t allow this
‘advantages’ only SBS to be developed any time soon in my opinion. Hence,
as the basic SBS has to many disadvantages, research has to focus on a
lighter, an practical way to build with bamboo studs.
3.2.2. Steel
Although traditionally all houses were built with wooden studs, a quick
investigation of steel studs walls shows, that some light industrial buildings
use this material, but its largest use is interior walls in high rise residential
and office buildings in dense cities like New York. They have certain
advantages I would like to address in this research. “Because of the strength
advantage produced by this bending process, steel framing material has a
strength-to-weight ratio that is very favorable when compared to most other
materials, particularly wood” (Waite, 1994). This makes it easy to carry
them around on building sites and hoisting them up to higher floors.
Furthermore, no sawdust is created when they are cut to size, which keeps

the jobsite cleaner, a big concern when there are neighbors close by.
“The gauge or thickness of sheet steel ranges from 10 to 25. By convention
the higher the gauge number the thinner the steel. The more light-weight

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non-load-bearing interior walls of residential structures are usually made of
25 gauge steel, while the exterior load-bearing steel studs are usually built
from stronger 18 or 20 gauge steel. (asceditor.unl.edu, dec 2004) The
problem being with these interior (25 gauge) studs is, that they are so thin
that they tend to get damaged during construction, before sheetrock is
placed. The replacement of studs and occasional crooked walls this causes
is one of the inconveniences of construction typology.
Weirton Steel Corporation (1995) advertises several advantages of steel.
Steel components weigh 60% less than wood. A 2000 square foot home
requires only 6 tons of steel compared to 20 tons of lumber. Also steel
components generate minimal waste and all light gauge steel construction
materials are 100% recyclable. On the contrary, steel’s biggest disadvantage
is its excellent thermal conductivity, making extra (exterior) insulation a
crucial need if one wants to build sustainable.
3.2.3. U-shaped Bamboo studs walls (Steel stud like)
The greater density of metal 7850 kg/m3 (490 lbs/cf) is compensated by its
efficient 25 gage U-shaped stud design. These studs have openings in their
members, to save weight, but also to allow electrical conduit to be passed
through them without alterations (wood studs require drilled holes on site
for these measures)
If one could develop and produce a bamboo-based product that has this
same efficiency and is installed in a similar fashion, this product would
combine certain advantages of wood (better thermal conductivity, wood like

modification) with steels (light, conduit openings), it would be a great
replacement of both products and thus have an enormous market potential.
As a starting point bamboo mat-corrugated board (BMB) was examined. To
make this product ”platens having approximated sinusoidal wave patterns
were designed to be fitted with hydraulic hot press to produce corrugated
sheets by using bamboo mat coated with suitable resin binder. Extensive
experiments were carried out using woven bamboo mats of Melaconna
bambusoides & Ochlandra travancorica that were dipped in phenol
formaldehyde resin and pressed under temperature and pressure”
(www.bambocomposites.com, dec 2004) (see Figure 8)

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Figure 8 Corrugated bamboo mat boards (www.bamboocomposites.com)

These mats are made from the higher part of the culm, that is more flexible
and cannot be used for bamboo flooring and plyboo. Using the higher part of
the clum, that is otherwise underutilized, eg. burned for heat or wasted,
increases the efficiency of bamboo plantations/harvesting and processing.
Especially since only the lower 4m of the culm of the Chinese bamboos is
used for plyboo/floors (P. van de Lugt, per e-mail). Hence this would be a
very useful application to use the upper part (mayority) of the plant for
bamboo-based studs.
Since these mats are flexible and can be pressed into a certain shape, I
think it is feasible to make a U-shape (metal like) stud, that conforms to the
standard 2x4 size. (See Figure 9)

Figure 9 U-shaped bamboo stud (FKB)


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The studs have 5 cm (2” ) diameter holes drilled in them to enable conduit
to be passed through. This also save somewhat on transportation costs and
lessens thermal conductivity (that was already better than steel).
Production
Bamboo is sliced into designated thicknesses and weaved into mats, as is
usual in BMB production. The only difference is the press that is used has
‘sharper’ corners than a regular corrugated press (see Figure 10 and the
drawing on the next page).

Figure 10 Corrugated BMB press (www.bamboocomposites.com oct 2005)

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The pressed form results in a corrugated board (assumed 3mm thick) with
right (radius 3-5 mm) corners. This is has to be determined by testing, the
sharper the fold, the stronger it will make the material and the tighter the
connections between the studs can be.
After it is pressed the edge of BMB are trimmed off and sliced in half
(horizontally). Woven sheets will must be 10’ 3050 mm high. The width
depends on the used machinery, which will determine the number (and size)
of the ‘2x4’ U-shaped bamboo studs (UBS) that are produced.
A variety of sizes could potentially be made from with the same press, when
fitted with different size press elements. The use for this is of course the

different sizing demands of the construction industry, but there is also a
need for slight width variations, which will be explained in the next
paragraph.

Figure 11 3-D view of UBS stud configuration (FKB)

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Connections for U-shaped bamboo studs
Just as one can assume SBSs have splitting problems with nails, a different
connection problem occurs with UBSs. When compared to metal stud walls
system, which has slightly wider runner tracks (1mm) that can receive the
studs, allowing easy installation with screws. A different solution has to be
found for UBS, which will be strong, efficient and quick.
When on considers that the thickness of the bamboo stud has to be at least
3mm (1/8”) then one can understand that the horizontal elements
(runner/header) have to be able to receive the stud, meaning they will be
just as wide on their interior, as the regular UBS is on its exterior (see
Figure 11) So to compensate for the 3mm thickness of UBS material on both
sides, the UBS-runner has to be 6mm wider to be able to receive the stud.
The last problem that has to be solved is how one connects the stud to the
track

Connecting UBS to runners with screws
“(…) considering how easily bamboo splits and how
difficult it is to glue it. Perhaps we need to find suitable fasteners
and methods for making connections. Perhaps screws can be
engineered for the singular purpose of holding bamboo -- screws that
bite into bamboo, but which will nonetheless require pilot holes to avoid

splitting. Fine threaded screws tend to strip out a hole in bamboo quite
readily. Perhaps a course threaded screw would be more effective, such
as drywall screws” (groups.yahoo.com oct 2005)
Connecting the runners to the floor can be achieved by pre-drilling holes,
and screwing them to the floors or concrete nailing them with a nail gun
with a washer. The biggest concern is the screwed connection from runner
to studs, as this is the majority of connections that will be made. If the UBS
can be screwed into without splitting it, so that the screw will make a decent
connection, that would be the easiest way to solve this problem. Otherwise
the pre-drilling would present a, time consuming and costly, alternative.
This is unfavorable from an economic point of view and is preferably avoided.
The woven BMB properties, being multidirectional (several layers of mat),
will decrease the likeliness of the material splitting. This has to be
researched on actual prototypes of the UBS system, which will determine if
the screws will split/restrict the connection, or that it is economically (timewise) feasible to pre-drill holes for this connection.
Connecting panels to the UBS and runners

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Whether the wall is load bearing or not, has large implications on how well
the connection between the internal elements (runners, studs, headers) and
the facing material (sheetrock, BMB, or actually any kind of continuous
material that can transfer stress-loads) should be. If the system can work as
a proper “sandwich construction”, this will make the wall significantly
stronger and most likely a suitable solution for a load-bearing construction.
If it is easier and more cost efficient, to built non-load bearing walls with a
different (faster) system, this should be for those reasons. The next section
will address both solutions for the UBS-system.


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