Note: Descriptions are shown in the official language in which they were submitted.
CA 02582774 2007-03-26
METHODS OF FORMING BUILDING WALL SYSTEMS
AND BUILDING WALL SYSTEMS
FIELD OF INVENTION
[0001] The present invention is directed to methods of forming a building wall
system and building wall systems. More particularly, the present invention
relates to
methods of making a building wall system and building wall systems that
comprise at least
three layers and are resistant to rain penetration.
BACKGROUND OF THE INVENTION
[0002] Insulating material is used in the construction of buildings. Popular
modern-day insulating materials include foam boards that are often
manufactured from a
polystyrene polymer having a laminated outer coating or facer. The foamed
polystyrene
boards have insulating properties associated therewith. The laminated coating
functions
primarily to protect the foamed polystyrene polymer and provide the foam board
with
enhanced protection, durability, strength and resiliency.
[0003] To form a building wall system, such existing foamed polystyrene boards
may be installed with a building paper or housewrap. The building paper or
housewrap
assists in preventing or inhibiting rain penetration. Building paper or
housewrap is presently
required if the exterior covering is not determined to be weather resistant
(e.g., brick, stone,
fiber, cement, and lapwood siding, vinyl siding, aluminum siding, or stucco).
[0004] It would be desirable to have a method of forming a building wall
system
and a building wall system itself that resists water penetration and does not
necessitate
building,paper or housewrap, while still providing desirable properties.
SUMMARY OF THE INVENTION
[0005] According to one method, a building wall system is formed in the
absence of building paper or housewrap. A generally flat structural insulating
sheathing is
provided that comprises at least a first layer, a second layer and a third
layer. The first layer
comprises an alkenyl aromatic polymer foam. The second layer comprises
paperboard. The
third layer comprises an alkenyl aromatic polymer foam. A stud wall is
provided. The
insulating sheathing is fastened to the stud wall to form the building wall
system such that a
seal is formed that inhibits water from penetrating therethrough. The building
wall system
in the absence of building paper or housewrap passes the test requirements set
forth in
Section 1403.2 of the 2003 International Building Code.
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[0006] According to another method, a building wall system is formed in the
absence of building paper or housewrap. A generally flat structural insulating
sheathing is
provided that comprises at least a first foam layer, a second layer and a
third foam layer.
The first foam layer comprises a polyolefin, polyisocyanurate, polyurethane,
polyester, or
combinations thereof. The second layer comprises paperboard. The third foam
layer
comprises a polyolefin, polyisocyanurate, polyurethane, polyester, or
combinations thereof.
A stud wall is provided. The insulating sheathing is fastened to the stud wall
to form the
building wall system such that a seal is formed that inhibits water from
penetrating
therethrough. The building wall system in the absence of building paper or
housewrap
passes the test requirements set forth in Section 1403.2 of the 2003
International Building
Code.
[0007] According to one embodiment, a building wall system in_ the absence of
building paper or housewrap, comprises a stud wall and a generally flat
structural insulating
sheathing. The generally flat structural insulating sheathing comprises at
least a first layer, a
second layer, and a third layer. The first layer comprises an alkenyl aromatic
polymer foam.
The second layer comprises paperboard. The third layer comprises an alkenyl
aromatic
polymer foam. The insulating sheathing is attached to the stud wall such that
a seal is
formed that inhibits water from penetrating therethrough. The building wall
system in the
absence of building paper or housewrap passes the test requirements set forth
in Section
1403.2 of the 2003 Tnternational Building Code.
[0008] According to another embodiment, a building wall system in the absence
of building paper or housewrap comprises a stud wall and a generally flat
structural
insulatirig sheathing. The generally flat structural insulating sheathing
comprises at least a
first layer, a second layer, and a third layer. The first layer comprises a
polyolefin,
polyisocyanurate, polyurethane, polyester, or combinations thereof. The second
layer
comprises paperboard. The third layer comprises a polyolefin,
polyisocyanurate,
polyurethane, polyester, or combinations thereof. The insulating sheathing is
attached to the
stud wall such that a seal is formed that inhibits water from penetrating
therethrough. The
building wall system in the absence of building paper or housewrap passes the
test
requirements set forth in Section 1403.2 of the 2003 International Building
Code.
[0009] According to one embodiment, a structural insulating sheathing adapted
to be used in a building wall system comprises a first layer, a second layer,
and a third layer.
The first layer comprises an alkenyl aromatic polymer foam. The second layer
comprises
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paperboard. The third layer comprises an alkenyl aromatic polymer foam. The
insulating
sheathing has a flexural strength of at least 170 psi as measured in
accordance with ASTM
C 393, an R-value of at least 2.0 (ft2)( F)(hr)/(BTU) as measured in
accordance with ASTM
C 518.
[0010] According to another embodiment, a structural insulating sheathing
adapted to be used in a building wall system comprises a first foam layer, a
second layer,
and a third foam layer. The first foam layer comprises a polyolefin,
polyisocyanurate,
polyurethane, polyester, or combinations thereof. The second layer comprises
paperboard.
The third foam layer comprises a polyolefin, polyisocyanurate, polyurethane,
polyester, or
combinations thereof. The insulating sheathing has a flexural strength of at
least 170 psi as
measured in accordance with ASTM C 393, an R-value of at least 2.0 (ft2)(
F)(hr)/(BTU) as
measured in accordance with ASTM C 518.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view of structural insulating sheathing according to
one
embodiment.
[0012] FIG. 2 is a side view of structural insulating sheathing according to
another embodiment.
[0013] FIG. 3 is a side view of structural insulating sheathing according to a
further embodiment.
[0014] FIG. 4 is a perspective view of the structural insulating sheathing of
FIG.
1 being attached to a stud wall using nails according to one embodiment.
[0015] FIG. 5 is an enlarged view of the generally circular shape FIG. 5 of
FIG.
4.
[0016] FIG. 6 is a perspective view of the structural insulating sheathing of
FIG.
1 being attached to a stud wall using staples according to one embodiment.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0017] The present invention is directed to building wall systems and methods
of
forming building wall systems that are resistant to rain penetration. The
present invention
serves as an air filtration retardant, drainage plain, and eliminates the need
for additional
weather protection, such as building paper or housewrap, to protect against
rain penetration.
The present invention eliminates the cost associated with forming and
installing the building
paper or the housewrap.
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[0018] Referring to FIG. 1, a generally flat structural insulating sheathing
10
according to one embodiment to be used in the building wall systems of the
present
invention is shown. The structural insulating sheathing 10 comprises a first
layer 12, a
second layer 14, and a third layer 16. The second layer 14 of FIG. 1 is
located between the
first layer 12 and third layer 16. It is contemplated that the insulating
sheathing may include
additional layers, such as described below in conjunction with FIGs. 2 and 3.
[0019] According to one embodiment, the first and third layers 12, 16 comprise
an alkenyl aromatic polymer foam. The term "alkenyl aromatic polymer" as used
herein
includes polymers of aromatic hydrocarbon molecules that contain an aryl group
joined to
an olefinic group with only double bonds in the linear structure, such as
styrene, a-
methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, a-
ethylstyrene, a-
vinylxylene, a-chlorostyrene, a-bromostyrene, and vinyl toluene. Alkenyl
aromatic
polymers also include homopolymers of styrene (commonly referred to as
polystyrene),
copolymers of styrene and butadiene, and rubber-toughened polystyrene
(commonly referred
to as high impact polystyrene or HIPS). The alkenyl aromatic polymer may be an
oriented
polystyrene (OPS). Another example of an alkenyl aromatic polymer foam is an
extruded
polystyrene foam.
[0020] According to another embodiment, the first and third layers 12, 16 of
the
structural insulating sheathing 10 may be formed by extruded polyolefin foam
resins. One
example of an extruded polyolefin foam that may be used in forming the first
and third
layers is an extruded polypropylene foam. It is contemplated that the
polyolefin resins may
be used in combinations with the alkenyl aromatic polymer resins. It is also
contemplated
that other foamed materials such as polyisocyanurate, polyurethanes, and
polyester may be
used alone or in combinations with the polyolefins and alkenyl aromatic
polymer foam
resins.
[0021] It is contemplated that the first and third layers 12, 16 may be
independently formed from different resins. The first and third layers 12, 16
of the
structural insulating sheathing 10 may be formed by an extrusion process. It
is
contemplated that the first and third layers may be formed by other processes.
[0022] The thickness of each of the first and third layers 12, 16 is generally
from
about 0.1 to about 1 inch. More specifically, the thickness of each of the
first and third
layers 12, 16 is generally from about 0.20 to about 0.50 inch. The thicknesses
of the first
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and third layers 12, 16 may be different.
[0023] The densities of the first and third layers 12, 16 are generally from
about
1 to about 3 lbs/ft3 and, more specifically, from about 1.5 to about 21bs/ft3.
To increase the
permeation of the water vapor, it is contemplated that the first and third
layers may be
perforated.
[0024] The second layer 14 of the structural insulating sheathing 10 comprises
paperboard. The term "paperboard" as used herein includes the broad
classification of
materials made from cellulosic fibers such as primarily wood pulp and recycled
paper stock
on board machines. The paperboard may be laminated paperboard that consists of
a
plurality of layers of paper adhesively secured to each other. Thus, the
second layer 14 may
be comprised of several layers that may be different.
[0025] The paperboard may be, for example, kraft paper, chipboard, fiberboard
and linerboard. Kraft paper as used herein includes pulp, paper or paperboard
produced
from wood fibers using a sulfate process. Chipboard as used herein includes
paperboard
that has been made from recycled paper stock. Fiberboard as used herein
includes
containerboard and vulcanized fiberboard. The fiberboard may be made from a
combination
of chemical pulp and recycled stock. Fiberboard as used herein also includes
defibrated
wood formed under heat and pressure and without the use of adhesives. The
paperboard
may also be a combination of one or more of the following: laminated
paperboard, kraft
paper, chipboard, fiberboard and linerboard.
[0026] The thickness of the second layer 14 of the structural insulating
sheathing
is generally from about 0.05 to about 0.25 inch and, more specifically, from
about 0.07 to
about 0.125 inch.
[0027] It is contemplated that additional layers may be used to form the
insulating sheathings. It is contemplated that optional laminated surface
coatings or facers
may be added to the insulating sheathing. Examples of insulating sheathings
with optional
laminated surface coatings are shown in FIGs. 2 and 3. In FIG. 2, a structural
insulating
sheathing 30 includes an optional laminated surface coating or facer 18
adjacent to and
attached to the first layer 12. The sheathing 30 also includes a second layer
14 and third
layer 16 as described above. In FIG. 3, a structural insulating sheathing 40
includes two
facers 18, 20 that are adjacent to and attached to the respective first and
third layers 12, 16.
The sheathing 40 also includes the second layer 14. Thus, as shown in FIGs. 2
and 3, one or
two facers may be added to the first and/or the third layers 12, 16.
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[0028] The optional laminated surface coatings or facers 18, 20 may be made of
materials such as polyolefins, high impact polystyrenes (HIPS), polyester,
metallized films,
foils, or combinations thereof. Examples of polyolefins that may be used to
form the facers
include polypropylenes and polyethyelenes. One example of laminated surface
coatings or
facers is aluminum foil. It is contemplated that other materials may be used
in forming the
optional laminated surface coatings or facers.
[0029] The thickness of the optional laminated surface coatings or facers is
generally from about 0.5 to about 3 mils and, more specifically, from about
0.7 to about 1
mil.
[0030] The first layer 12, the second layer 14, and the third layer 16 that
form the
structural insulating sheathing 10 may be attached by several methods. For
example, these
layers may be attached to each other using an adhesive such as polyvinyl
acetate,
polyurethane, polyvinyl alcohol, or combinations thereof. It is contemplated
that other
adhesives may be used in attaching these layers.
[0031] The optional laminated surface coatings or facers 18, 20 may be
attached
to the first and third layers 12, 16 by the use of an adhesive. Examples of
suitable adhesives
include ethylene vinyl acetate (EVA), a mixture of EVA in polyethylene,
ethylene vinyl
alcohol (EVOH), block copolymers comprising polymeric regions of styrene-
rubber-styrene
such as KRATONO made by Shell Chemical Company, and modified EVAs such as
BYNEL made by Dupont. Modified EVAs generally have indices from about 6.4 to
about
25 g/10 min. as measured by ASTM D 1238 and densities from about 923 to about
947
kg/m3 as measured by ASTM D 1505. It is contemplated that other suitable
adhesives may
be used. '
[0032] The structural insulating sheathing 10 is a generally flat board sheet
that
may be manufactured in a variety of sizes. Popular sizes in the housing market
include a 4'
x 8' flat board sheet (4 feet by 8 feet) and a 4' x 9' flat board sheet (4
feet by 9 feet).
[0033] According to one method, insulating sheathing is provided, such as
depicted in FIG. 1 with structural insulating sheathing 10. The building wall
system may be
formed in the absence of building paper or housewrap. In forming the building
wall system,
an insulating sheathing and a stud wall are provided. In FIG. 4, for example,
a building wall
system 60 is depicted that includes the structural insulating sheathing 10, a
stud wal170, and
fasteners (e.g., nails 80). The fasteners 80 attach the structural insulating
sheathing 10 to the
stud wall 70.
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[0034] According to one embodiment, the stud wall is made of wood. The stud
wall, however, may be made of metal. One specific example of a stud wall is a
2 x 4 wood
stud. It is contemplated that other sized wall studs may be used. The
insulating sheathing is
fastened to the stud wall by, for example, nails, adhesive, or staples.
[0035] Nails are desirable because they improve the structural strength of the
building wall system as measured by ASTM E 72-98 (Section 14 Racking Load).
One
example of a nail that may be used is a 1-3/4 inch long roof nail. Such a nail
desirably
penetrates the third layer 16 of the structural insulating sheathing 10 such
that the head of
the nail is located near or at the face of the second layer 14. It is
desirable for the head of
the nail to be resting securely against the face of the second layer 14. For
example, the head
of the nail may be positioned such that some of the foam is compressed between
the nail and
the face of the second layer 14. During the fastening, the structural
insulating sheathing and
more specifically the first layer 12 of the structural insulating sheathing 10
forms a tight seal
(e.g., like using a gasket) against the studs to prevent or inhibit rain from
penetrating
therethrough. Although not necessary, it is desirable for the nail to be
installed using a
pneumatic nail gun to assist in properly placing the nail and improving the
efficiency of the
installation process.
[0036] The fastening of the structural insulating sheathing may be done by
staples. In FIG. 6, for example, a building wall system 160 is depicted that
includes the
structural insulating sheathing 10, a stud wall 70, and fasteners (e.g.,
staples 180). The
staples desirably penetrate the third layer 16 of the structural insulating
sheathing 10 such
that the crown of the staple is located near or at the face of the second
layer 14. It is
desirable for the crown of the staple to be resting securely against the face
of the second
layer 14. For example, the crown of the staple may be positioned such that
some of the
foam is compressed between the staple and the face of the second layer 14.
During the
fastening, the insulating sheathing and more specifically the first layer 12
of the structural
insulating sheathing 10 forms a tight seal (e.g., like using a gasket) against
the studs to
prevent or inhibit rain from penetrating therethrough.
[0037] Staples are typically installed using a pneumatic staple gun to assist
in
properly placing the staple and improving the efficiency of the installation
process. In one
method, the staples are positioned generally perpendicular to the stud walls.
The staples
may be positioned in other locations with respect to the stud walls including
being
perpendicular to the stud walls. It is also desirable to position the staples
such that the edges
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of the foam do not raise from the stud walls. The crown of the staples may
vary in size but
are generally from about 7/16 to about 1 inch. If the staples are positioned
generally
perpendicular or perpendicular to the stud walls, then the staples are
generally smaller in
size, such as 7/16", to assist in ensuring that the staples are positioned
into the stud walls.
The depth of the staples are generally from about 1 to about 1 3/4 of an inch.
[0038] According to another embodiment, the insulating sheathing is attached
to
the stud wall using a general construction adhesive. Examples of general
construction
adhesives include, but are not limited to, acrylics, urethanes, and silicones.
[0039] Because of its rain penetration protection, the building wall systems
eliminate the necessity to have additional weather protection such as building
paper or
housewrap. The building wall systems also eliminate the necessity to tape the
joints formed
between adjacent insulating sheathing boards. Thus, the methods of installing
the building
wall systems do not necessarily need building paper or housewrap, or taping or
sealing the
joints between adjacent insulating sheathing boards. It is contemplated,
however, that such
building paper or housewrap, or taping may be used.
[0040] The insulating sheathing may be used in the stud walls that form
residential or commercial buildings. Additionally, the insulating sheathings
may be used in
new construction and in remodeling or retrofitting of existing structures. On
a building, the
insulating sheathings are typically covered by an exterior covering such as
siding, brick,
stucco, stone, and cement. The insulating sheathings may be used with exterior
covering
that are not determined to be weather resistant (e.g., brick, stone, fiber,
cement, and lapwood
siding, vinyl siding, aluminum siding, or stucco).
[0041] The methods of forming the building wall systems of the present
invention pass the test requirements set forth in Section 1403.2 of the 2003
International
Building Code entitled "Weather Protection." Section 1403.2 of the 2003
International
Building Code mentions and incorporates ASTM E-331. ASTM E331-00 is entitled
"Standard Test Method for Water Penetration of Exterior Windows, Skylights,
Doors, and
Curtain Walls by Uniform Static Air Pressure Difference."
[0042] The building wall system forms a weather-resistant barrier that
protects
the interior wall cavity from water intrusion by demonstrating resistance to a
wind-driven
rain at a minimum differential pressure of 6.24 lbs/ft2 (0.297 kN/m2) for two
hours in
accordance with Section 1403.2 of the 2003 International Building Code. The
minimum
differential pressure of 6.24 Ibs/ft2 (0.297 kN/m2) correlates to a wind speed
of about 50
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miles per hour (mph).
[0043] The methods of forming the building wall systems provide desirable
structural strength as measured in accordance with ASTM E 72-98 (Section 14
Racking
Load). By having such desired structural strength, additional building
materials such as
corner plywood, corner OSB (oriented strand board), diagonal bracing, shear
panels, and
metal corner strapping are not needed. Thus, the corners in any such building
wall systems
remain better insulated because the insulating sheathing will be used instead
of the above-
discussed additional building material.
[0044] The structural insulating sheathing generally has a flexural strength
greater than at least 170 psi and desirably greater than 225 psi in accordance
with ASTM C
393. The structural insulating sheathing more typically has a flexural
strength greater than
at least 300 psi and desirably greater than 400 psi in accordance with ASTM C
393.
[0045] The generally flat structural insulating sheathing desirably has a
permeability greater than 1 perm as measured in accordance with ASTM E 96. The
R-value
of the generally flat structural insulating sheathing is generally greater
than about 2.0
(ft2)( F)(hr)/(BTU) as measured in accordance with ASTM C 518. It is
contemplated that
the R-value of the generally flat structural insulating sheathing may be
greater than 2.5 or
3.0 (ft2)( F)(hr)/(BTU) as measured in accordance with ASTM C 518.
Examples
Comparative Example 1:
[0046] The wood stud wall system of Comparative Example 1 was evaluated in
accordance with Section 1403.2 of the 2003 International Building Code, which
mentions
and incorporates ASTM E 331-00 entitled "Standard Test Method for Water
Penetration of
Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air
Pressure
Difference." Section 1403.2 of the 2003 International Building Code calls for
a minimum
differential pressure of 6.24 lbs/ft2 (0.297 kN/m2). Since this minimum
differential pressure
correlates to about 50 miles per hour (mph), the testing was done using a 50
miles per hour
wind speed.
[0047] The insulating sheathing comprised an extruded polystyrene foam flat
board with polyethylene film facers. The overall size of the insulating
sheathing was 48"
wide by 96" high (48 inches by 96 inches) with a large sheet measuring 32"
wide by 96"
high and a small sheet measuring 16" wide by 96" high. The insulating
sheathing had a
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total thickness of about %Z" (inch). Specifically, the insulating sheathing
had a 0.42" thick
extruded polystyrene foam board adhesively bonded to a 0.002" thick plastic
facer on both
sides. No reinforcement tapes or sealants were used.
[0048] The insulating sheathing was secured to a 2 x 4 Spruce-Pine-Fir wood
buck measuring 48" x 96" with two vertical studs 16" (inches) on center. The
insulating
sheathing was cut into two pieces -- a large sheet measuring 32" wide by 96"
high and a
small sheet measuring 16" wide by 96" high. These two pieces were abutted
together at one
of the vertical studs. The insulating sheathing was secured to the wood buck
using 1-1/2"
plastic cap nails, 1" from each corner and spaced 3" apart, except at the
vertical stud with no
buttjoint. The nails were spaced 6" apart.
[0049] As a result of this testing under Section 1403.2, leakage occurred at
the
nail holes and sheathing edges in Comparative Example 1.
Comparative Example 2:
[0050] The wood stud wall system of Comparative Example 2 was evaluated in
accordance with Section 1403.2 of the 2003 International Building Code, which
mentions
and incorporates ASTM E 331-00 entitled "Standard Test Method for Water
Penetration of
Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air
Pressure
Difference." Section 1403.2 of the 2003 International Building Code calls for
a minimum
differential pressure of 6.241bs/ft2 (0.297 kN/mZ). Since this minimum
differential pressure
correlates to about 50 miles per hour (mph), the testing was done using a 50
miles per hour
wind speed.
[0051] The insulating sheathing comprised an extruded polystyrene foam flat
board with polyethylene film facers. The overall size of the insulating
sheathing was 48"
wide by 96" high (48 inches by 96 inches) with a large sheet measuring 32"
wide by 96"
high and a small sheet measuring 16" wide by 96" high. The insulating
sheathing had a
total thickness of about %Z" (inch). Specifically, the insulating sheathing
had a 0.42" thick
extruded polystyrene foam board adhesively bonded to a 0.002" thick plastic
facer on both,
sides. No reinforcement tapes or sealants were used.
[0052] The insulating sheathing was secured to a 2 x 4 Spruce-Pine-Fir wood
buck measuring 48" x 96" with two vertical studs 16" (inches) on center. The
insulating
sheathing was cut into two pieces -- a large sheet measuring 32" wide by 96"
high and a
small sheet measuring 16" wide by 96" high. These two pieces were abutted
together at one
CA 02582774 2007-03-26
of the vertical studs. The insulating sheathing was secured to the wood buck
using 1-1/2"
long, 1" crown staples, 1" from each corner and spaced 3" apart, except at the
vertical stud
with no butt joint. The staples were spaced 6" apart.
[0053] As a result of this testing under Section 1403.2, leakage occurred at
the
staple holes and sheathing edges in Comparative Example 2.
Inventive Example 1:
[0054] The wood stud wall system of Inventive Example 1 was evaluated in
accordance with Section 1403.2 of the 2003 International Building Code, which
mentions
and incorporates ASTM E 331-00 entitled "Standard Test Method for Water
Penetration of
Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air
Pressure
Difference." Section 1403.2 of the 2003 International Building Code calls for
a minimum
differential pressure of 6.24 lbs/ft2 (0.297 kN/m2). Since this minimum
differential pressure
correlates to about 50 miles per hour (mph), the testing was done using a 50
miles per hour
wind speed.
[0055] The structural insulating sheathing was an extruded polystyrene foam
flat
board with a layer of laminated paperboard therebetween. The paperboard
comprised five
identical layers of kraft paper that were laminated together. The overall size
of the
insulating sheathing was 48" wide by 96" high (48 inches by 96 inches) with a
large sheet
measuring 32" wide by 96" high and a small sheet measuring 16" wide by 96"
high. The
insulating sheathing had a total thickness of %Z" (inch). The insulating
sheathing had two
0.20" thick extruded polystyrene foam pieces adhesively bonded to respective
sides of a
0.095" thick paperboard panel. No reinforcement tapes or sealants were used.
[0056] The insulating sheathing was secured to a 2 x 4 Spruce-Pine-Fir wood
buck measuring 48" x 96" (feet) with two vertical studs 16" (inches) on
center. The
insulating sheathing was cut into two pieces -- a large sheet measuring 32"
wide by 96" high
and a small sheet measuring 16" wide by 96" high. These two pieces were
abutted together
at one of the vertical studs. The insulating sheathing was secured to the wood
buck using 1-
3/4" galvanized roofing nails, 1" from each corner and spaced 3" apart, except
at the
vertical stud with no butt joint. The nails were spaced 6" apart.
[0057] As a result of this testing under Section 1403.2, no leakage occurred
in
Inventive Example 1.
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Inventive Example 2:
[0058] The wood stud wall system of Inventive Example 2 was evaluated in
accordance with Section 1403.2 of the 2003 International Building Code, which
mentions
and incorporates ASTM E 331-00 entitled "Standard Test Method for Water
Penetration of
Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air
Pressure
Difference." Section 1403.2 of the 2003 International Building Code calls for
a minimum
differential pressure of 6.241bs/ft2 (0.297 kN/m2). Since this minimum
differential pressure
correlates to about 50 miles per hour (mph), the testing was done using a 50
miles per hour
wind speed.
[0059] The structural insulating sheathing was an extruded polystyrene foam
flat
board with a layer of laminated paperboard therebetween. The paperboard
comprised five
identical layers of kraft paper that were laminated together. The overall size
of the
insulating sheathing was 48" wide by 96" high (48 inches by 96 inches) with a
large sheet
measuring 32" wide by 96" high and a small sheet measuring 16" wide by 96"
high. The
insulating sheathing had a total thickness of %2" (inch). The insulating
sheathing had two
0.20" thick extruded polystyrene foam pieces adhesively bonded to respective
sides of a
0.115" thick paperboard panel. No reinforcement tapes or sealants were used.
[0060] The insulating sheathing was secured to a 2 x 4 Spruce-Pine-Fir wood
buck measuring 48" x 96" (feet) with two vertical studs 16" (inches) on
center. The
insulating sheathing was cut into two pieces -- a large sheet measuring 32"
wide by 96" high
and a small sheet measuring 16" wide by 96" high. These two pieces were
abutted together
at one of the vertical studs. The insulating sheathing was secured to the wood
buck using 16
gauge, i-3/4" Senco staples with 7/16" crown and a pneumatic fastening system.
The
staples were fastened at 3" on center at all edges and 6" on center in the
field. Staples were
installed at a depth where they were considered to be firmly resting on the
paperboard layer
of the sheathing upon insertion.
[0061] As a result of this testing under Section 1403.2, no leakage occurred
in
Inventive Example 2.
[0062] While the present invention has been described with reference to one or
more particular embodiments, those skilled in the art will recognize that many
changes may
be made thereto without departing from the spirit and scope of the present
invention. Each
of these embodiments and obvious variations thereof is contemplated as falling
within the
spirit and scope of the claimed invention, which is set forth in the following
claims.
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