Strawbales in Building Materials and Construction

1. BUILDING MATERIALSAND CONSTRUCTION 01
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2. U
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IT05:ST
RA
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ALES
BUILDINGMATERIALSA
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Straw as a building material. Physical aspects - Basics, Fire, moisture, insects and pests
proof. Plastering straw bale walls, straw bale roof.

3. ST
RA
WB
ALES
Straw bale construction usesbaled straw
from wheat, oats, barley, rice and others in
walls covered by earthen or lime stucco.
BUILDINGMATERIALSA
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4. ST
RAWB
ALES
Straw isalsobeing usedasa building material currently insheet
materials suchas sheathing and wall panels.
Straw is used to bind clay and concrete. A mixture of clay and
straw, known as cob, can be used as a building material.
Straw-bale construction is a building method that usesbales of
straw asstructuralelements,building insulation,or both. This
constructionmethodiscommonlyusedinnatural building or
"green" construction projects.
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5. ST
RAWB
ALES
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6. ST
RAWB
ALES
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7. ST
RAWB
ALES
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8. ST
RAWB
ALES
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9. ST
RAWB
ALES
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10. ST
RAWB
ALES
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11. ST
RAWB
ALES:U
SES
Energy efficiency – Thermal Insulation
Sound proofing
Environmental responsibility
Natural Materials
Aesthetics
Minimize wood consumption
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12. ST
RAWB
ALES:W
ALLS
Straw bale building typically consists of stacking rows of bales
on a raised footing or foundation, with a moisture barrier or
capillary break between the bales and their supporting
platform.
Bale walls can be tied together with pins of bamboo, rebar, or
wood (internal to the bales or on their faces), or with surface
wire meshes, and then stuccoed or plastered, either with a
cement-based mix, lime-based formulation, or earth/clay
render.
Thebales mayactually provide thestructuralsupport for the
building ("load-bearing" or "Nebraska-style" technique), as was
the case in the original examples from the late 19th century.
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13. ST
RAWB
ALES:W
ALLS
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14. ST
RAWB
ALES:W
ALLS
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15. ST
RAWB
ALES:W
ALLS
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16. ST
RAWB
ALES:W
ALLS
LAID FLAT.Refers to stacking bales so that the sides with the
largest cross-sectionalarea are horizontal and thelongest
dimensionof this area is parallel with the wall plane.
LAID ON EDGE.Refers to stacking bales so that the sides with
thelargest cross-sectional area are vertical and thelongest
dimensionof thisarea ishorizontal and parallel with thewall
plane.
Wall thickness. Nominal minimumbale wall ,thicknessshall be 14
inches (356 mm).
Custom size bales. Where custom made partial bales are used,
they shallbe of thesamedensity,same string or wire tension,
and where possible, use the same number of ties as the
standard size bales.
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17. ST
RAWB
ALES:PLAST
ERIN
G
Stucco. Cement stucco shall be reinforced with galvanized woven
wire, stucco netting or an acceptable equivalent.
Such reinforcement shall be secured by attachment through the
wall at a maximum spacing of 24 inches(610 mm) horizontally
and 16 inches (4061 mm) vertically, using a method approved
by the building official.
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18. ST
RAWB
ALES:PLAST
ERIN
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19. ST
RAWB
ALES:PLAST
ERIN
G
BUILDINGMATERIALSA
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20. ST
RAWB
ALES:PLAST
ERIN
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BUILDINGMATERIALSA
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21. ST
RAWB
ALES:ISSU
ES
Two significant problems related to straw-bale construction are moisture and mold.
Duringtheconstructionphase,buildingsneed to be protected from rain and from water
leakages into the body of the walls. If exposed to water, compressed straw may expand
due to absorption of moisture.Inturn,thiscancausemorecracking throughwhichmore
moisture can infiltrate.
In hot climates, where walls may have become internally dampened, internal temperatures
mayrise (dueto decomposition of affected straw).While fire is generally considereda
rare event,compressedstrawor hay bales havetheseriouspotential of undergoing
spontaneousinternal combustion.
Rats and mice can infiltrate straw bale homesduring construction, so care must be taken to
keep suchanimalsout of the material.
Other problems relate to straw dust which may cause breathing difficulties among people
with allergies to straw or hay.
Severalcompanieshavedeveloped prefabricated strawbale walls. Apassiveecological
house can easily be assembled with those panels.
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22. ST
RAWB
ALES:FOU
N
D
AT
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BUILDINGMATERIALSA
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23. ST
RAWB
ALES:FOU
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24. ST
RAWB
ALES:RAMMEDEAR
T
H
BUILDINGMATERIALSA
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25. ST
RAWB
ALES:W
ALL
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26. ST
RAWB
ALES:OPEN
IN
G
S
BUILDINGMATERIALSA
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27. ST
RAWB
ALES:R
OOFPLAT
E
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