corrugated bamboo roofing sheets
TRANSCRIPT
Corrugated Bamboo Roofing Sheets
SUBMITTED BY-
UTKARSH DWIVEDI
B.ARCH SEM III-B
ENROLMENT NO.-A8304013046
What are Corrugated Bamboo Roofing Sheets?
Corrugated bamboo roofing sheets (CBRS)
are an excellent alternative to corrugated
metal, plastic or asbestos roofing sheets.
They are produced from a natural and
sustainable resource and can be used to
cover homes, storage facilities, animal
pens and many other temporary or
permanent structures.
How are Corrugated Bamboo Roofing Sheets Made?
• CBRS is made from several layers of
woven bamboo mats. These woven mats
are impregnated with an adhesive resin
and pressed together between two
specially designed corrugated pressing
plates. The sheets can be produced in a
range of sizes to suit particular
requirements and can easily be trimmed
for special applications.
• The main materials used are bamboo slivers to produce the mats, and adhesive resin in which to soak the mats. A resin applicator is needed, and a drying chamber is optional. Corrugated pressing plates for the hot press are of course essential.
The process of producing CBRS involves 6 steps:• Bamboos are split into thin slivers.
• Slivers are woven into mats.
• Mats are soaked in adhesive resin.
• Mats are allowed to drain and dry.
• Mats are glued together under high temperature and pressure.
• Sheets are trimmed to shape.
PRECAUTION
• An important precaution to be taken in
making mats for BMCS production is that
slivers with the glossy (epidermal) layer
should be avoided as they are resistant to
bonding. Such slivers can however be
used in basketry etc.
• The moisture content (m.c) of freshly
woven mats is in the range of 40% -50%.
On drying them in sun, the m.c is
generally about 12% - 15%. If transport
and or storage is more than one month it
is advisable to undertake prophylactic
treatment. The simplest and significantly
effective treatment for mats, provided
they are not exposed to drying, is
spraying with 1% solution of mixture of
boric acid and borax in the ratio of 1:1.
Spraying can be done by hand or
knapsack sprayer. This will not have any
adverse effect on bonding. The mats
should be dried after prophylactic
Joinery details
BMCS are anchored to bamboo purlinsUsing J bolts
Detail showing how BMCS are joined to bamboo purlins using J bolts at the crest
BMCS should be bolted at crest not trough. Detail showing overlap of
BMCS .
Accessories can be used to resolve corners and joints problems.
Complete house with BMCS roofing
Main advantages of CBRS
• Bamboo roofing sheets are
environmentally friendly and a safe
alternative to plastic, zinc or corrugated
asbestos roofing panels.
• They have the same standard
measurements as conventional
corrugated roofing sheets.
• Bamboo roofs are quieter in the rain and
cooler in the sun than conventional metal
or plastic sheets. A study has shown that
cows in sheds roofed with bamboo yield
more milk than those under corrugated
zinc sheets because of the cooler
environment.
• Bamboo sheets are durable and strong
with excellent internal bond strengths and
a high resistance to weathering, fire or
insect attacks.
• They have an attractive and natural
appearance and are easy to work with
Comparing CBRS Materials
How do bamboo corrugated roofing sheets compare to zinc, plastic or asbestos roofing sheets? The following study compares the mechanical properties and performance differences between the four different
materials.
1. Thermal Transmission Performance
Bamboo has the highest thermal
resistance and the lowest thermal
transmission coefficient, therefore,
bamboo has the best thermal
isolation properties compared to the
other three materials.
MATERIAL THERMAL RESISTANCE(m²K/W)
Coefficient of thermal transmission W/(m²K)
Bamboo 0.030 5.2
Zinc 0.012 6.2
Plastic 0.007 6.4
Asbestos 0.019 5.9
2. Density and Water Absorption Properties
Bamboo has the lowest density and the
highest water absorption ratio compared
to plastic and asbestos which may
influence its durability in exterior use.
However, this characteristic is easy to
overcome when using better resins in
the production process or by applying
a coated outer layer.
Material Density (g/cm³) Water absorption ratio (%)
Bamboo 0.71 36.7
Plastic 1.56 1.7
Asbestos 1.60 21.1
3. Bending StrengthBecause zinc and plastic sheets are too thin
to determine its strength properties, the
determination was done with bamboo and
asbestos sheets only.
The results have shown that bamboo has a
higher bending strength than corrugated
asbestos board, and would be greatly
superior to plastic sheets. This means that
corrugated bamboo roofing sheets can
endure larger long-time loads in employment.
Material Flexural strength(MPa)
Bamboo 39.72
Asbestos 31.91
4. Impact strength
Corrugated bamboo roofing sheets
have an excellent impact strength.
They bare a much higher instant
striking force compared to asbestos
sheets.
Material Impact strength(MPa)
Bamboo 9.93
Asbestos 2.55
Building Materials & Technology Promotion Council (BMTPC)
• Under a project funded by BMTPC a technology for manufacturing BMCS has been developed at IPIRTI(indianplywood industries research and training institute) where pilot scale/experimental BMCS production facility has also been established and commercial scale of production has been established at M/s. Timpack Pvt. Ltd., Byrnihat, Meghalaya.
• More than 2000 BMCS made at the pilot facility at IPIRTI have already been used
Some of them are;-
• a rain shelter at the National Zoo, New
Delhi;
• specially designed terrace café at the
DFID India office, New Delhi;
• pantry near Glass House at Karnataka
Raj Bhawan, Bangalore; (Ar.neelam
Manjunatth)
• Bamboo houses constructed at
Bangalore under DFID funded project
“Bamboo Shelter Demonstration of
Best Construction Practices”
implemented by IPIRTI in
collaboration with TRADA Technology
of UK.
.