U.S. patent application number 10/752150 was filed with the patent office on 2004-08-05 for insulated building structures containing compressible cpi foam and a method for their fabrication.
Invention is credited to Bibee, Douglas V., Lacey, Timothy C., Malone, Bruce A..
Application Number | 20040148889 10/752150 |
Document ID | / |
Family ID | 32655729 |
Filed Date | 2004-08-05 |
United States Patent
Application |
20040148889 |
Kind Code |
A1 |
Bibee, Douglas V. ; et
al. |
August 5, 2004 |
Insulated building structures containing compressible CPI foam and
a method for their fabrication
Abstract
Fabricate an insulated building structure by applying a
compressible polymeric insulating (CPI) foam over sheathing
material such that a portion of the CPI becomes compressed between
a window frame and/or door frame or jamb.
Inventors: |
Bibee, Douglas V.;
(Granville, OH) ; Lacey, Timothy C.; (Midland,
MI) ; Malone, Bruce A.; (Midland, MI) |
Correspondence
Address: |
THE DOW CHEMICAL COMPANY
INTELLECTUAL PROPERTY SECTION
P. O. BOX 1967
MIDLAND
MI
48641-1967
US
|
Family ID: |
32655729 |
Appl. No.: |
10/752150 |
Filed: |
January 6, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60439323 |
Jan 9, 2003 |
|
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|
Current U.S.
Class: |
52/481.1 ;
52/745.09 |
Current CPC
Class: |
E04B 1/78 20130101; E04C
2/386 20130101; E04B 2001/742 20130101; E04B 2/707 20130101 |
Class at
Publication: |
052/481.1 ;
052/745.09 |
International
Class: |
E04C 002/34; E04B
001/00 |
Claims
What is claimed is:
1. An insulated building structure comprising a support structure,
a sheathing material, and a compressible polymeric insulative (CPI)
foam; wherein the support structure and sheathing material have
opposing inner and outer surfaces with the inner surface of the
sheathing material attached to the outer surface of the support
structure and wherein the CPI foam has opposing major surfaces with
one major surface contacting the outer surface of the sheathing
material; said CPI foam having a solid polymer matrix phase
comprising a polymer resin containing polymerized propylene
monomers, said CPI foam also having: a) a thickness of greater than
0.125 inches (3.2 millimeters) and 0.75 inches (19.0 millimeters)
or less; b) a compressive strength at 10% compression of 10 pounds
per square inch (68.9 kilopascals) or less, according to ASTM
method D3575-00-D; and c) a water pick-up of less than 5% by both
submersion testing (ASTM D3575-00L) and freeze/thaw testing (ASTM
C666-97, 25 cycles).
2. The building structure of claim 1, further comprising a door
with its associated frame, a window with its associated frame, or
both a door with its associated frame and a window with its
associated frame, wherein the door, or the window, whichever is
appropriate, penetrates through both the CPI foam and the sheathing
material, and at least a portion of the CPI foam is disposed
beneath, and compressed by, the door frame, the window frame or
both the door frame and the window frame, whichever is
appropriate.
3. The building structure of claim 1, wherein the CPI foam has a
density of 0.5 pounds per cubic foot (8 kilograms per cubic meter)
or more and 1.5 pounds per cubic foot (25 kilograms per cubic
meter) or less.
4. The building structure of claim 1, wherein the CPI foam is
sufficiently flexible to bend around a one-inch (25.4 millimeter)
diameter mandrel without breaking, yet sufficiently rigid so as to
not bend more than 45.degree. in the Horizontal Bend Test.
5. The building structure of claim 1, wherein the CPI foam has an
average cell size of one millimeter or less.
6. The building structure of claim 1, wherein the CPI foam
comprises multiple distinguishable polymeric foam strands.
7. The building structure of claim 1, wherein the CPI foam contains
multiple perforations through at least one surface of the CPI
foam.
8. The building structure of claim 1, wherein the CPI foam has a
water-vapor permeability of one or more and 20 or less perms
according to ASTM method E96-00.
9. The building structure of claim 1, wherein the CPI foam has at
least one groove traversing the major surface contacting the
sheathing material; and wherein said groove penetrates through the
CPI foam surface contacting the sheathing material to a depth of
less than the CPI foam's thickness.
10. A method for fabricating the insulated building structure of
claim 1, the method comprising: a) providing a support framework
that has opposing inner and outer surfaces, and a CPI foam with
opposing major surfaces; b) placing a sheathing material that has
opposing inner and outer surfaces in operative contact with the
support structure such that the inner surface of the sheathing
material contacts at least surface portions of the support
structure outer surface and attaching the sheathing material to the
outer surface of the support structure; c) securing a CPI foam to
the outer surface of the sheathing material so that a major surface
of the CPI foam contacts the outer surface of the sheathing
material, the CPI foam having a solid polymer matrix phase
comprising a polymer resin containing polymerized propylene
monomers to the outer surface of the sheathing material so that a
major surface of the CPI foam contacts the outer surface of the
sheathing material, the CPI foam having: i) a thickness of greater
than 0.125 inches (3.2 millimeters) and 0.75 inches (19.0
millimeters) or less; ii) a compressive strength at 10% compression
of 10 pounds per square inch (68.9 kilopascals) or less, according
to ASTM method D3575-00-D; and iii) a water pick-up of less than 5%
by both submersion testing (ASTM D3575-00L) and freeze/thaw testing
(ASTM C666-97, 25 cycles).
11. The method of claim 10, further comprising sequential steps: d)
providing at least one opening through both the CPI foam and
sheathing material, each opening being of sufficient dimensions to
accommodate only a window or a door, whichever is appropriate; e)
inserting a door or window of a door and associated frame
combination or a window and associated frame combination, whichever
is appropriate, and applying pressure against the associated frame
sufficient to compress at least a portion of the CPI foam against
the outer surface of the sheathing material; and f) securing the
associated frame to the sheathing.
12. The method of claim 10, wherein the CPI foam has a density of
0.5 pounds per cubic foot (8 kilograms per cubic meter) or more and
1.5 pounds per cubic foot (25 kilograms per cubic meter) or less
according to ASTM method D3575-93W.
13. The method of claim 10, wherein the CPI foam is sufficiently
flexible to bend around a one-inch (25.4 millimeter) diameter
mandrel without breaking, yet sufficiently rigid so as to not bend
more than 45.degree. in the Horizontal Bend Test.
14. The method of claim 10, wherein the CPI foam has an average
cell size of one millimeter or less according to ASTM method
D3576.
15. The method of claim 10, wherein the CPI foam comprises multiple
distinguishable polymeric foam strands.
16. The method of claim 10, wherein the CPI foam contains multiple
perforations through at least one surface of the CPI foam.
17. The method of claim 10, wherein the CPI foam has a water-vapor
permeability of one or more and 20 or less perms according to ASTM
method E96-00.
18. The method of claim 10, wherein the CPI foam has at least one
groove traversing the major surface contacting the sheathing
material and penetrating through the CPI foam surface to a depth of
less than the CPI foam's thickness.
19. The method of claim 10, wherein step (c) occurs prior to step
(b).
Description
CROSS-REFERENCE TO PRIOR APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/439,323 filed Jan. 9, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an insulated building
structure and a method for its fabrication.
[0004] 2. Description of Related Art
[0005] One common type of building construction utilizes a support
framework covered on its outside surface with a sheathing material.
Inside sheathing such as drywall often goes on an inside surface of
a support framework. A typical support framework comprises a
plurality of framework members such as "two-by" lumber (e.g.,
2.times.4, 2.times.6, and 2.times.8 boards). Sheathing material,
such as oriented strand board (OSB), is generally applied to the
outside of a support framework to enhance structural stability.
Exterior coverage, such as aluminum or vinyl siding, can go
directly over the sheathing material.
[0006] Buildings usually include windows and doors. Installation of
windows and doors typically occurs by cutting a hole through
sheathing material and inserting a window or door at specifically
designed locations in a support framework.
[0007] Manufacturers design standard window and doorframes to allow
for a standard wall thickness for use in insulated building
construction. For example, a standard wall thickness when using a
2.times.4 lumber support framework is between 4.44 inches (113
millimeter (mm)) and 4.56 inches (116 mm) thick. The wall thickness
accounts for 0.5 inch (12.7 mm) drywall, a 3.5 inch (88.9 mm) stud,
and {fraction (7/16)} inches (11.1 mm) to {fraction (9/16)} inches
(14.3 mm) of sheathing material. If a wall is made using 2.times.6
lumber, the standard wall thickness is an additional 2 inches (50.6
mm) thick. If a wall has a thickness other than a standard
thickness, jamb extensions are necessary for windows and doors.
Jamb extensions undesirably increases, for example, a window's cost
by $50-$60 dollars.
[0008] Recently, building construction containing a support
framework and sheathing materials also include a housewrap or
insulative foam between the sheathing material and exterior
coverage in an effort to further isolate a building's interior
environment from its exterior environment.
[0009] Housewraps serve as air barriers around building walls,
covering joints between sections of sheathing materials. Housewraps
tend to be permeable to water vapor, allowing moisture that may be
near sheathing material to escape.
[0010] Cellular plastic or plastic foam generally consists of at
least two phases; a solid polymer matrix and a gaseous phase
derived from a blowing agent. The gaseous phase is dispersed within
the solid polymer matrix either as discrete, non-interconnecting
cells (usually referred to as "closed cell foam") or with some
degree of interconnectivity between adjacent cells (usually
referred to as "open cell foam").
[0011] Insulative foam is an attractive alternative to a housewrap.
Insulative foam can both serve as an air barrier and provide
additional thermal insulation in a building wall. Typical
insulative foams for use against sheathing material in building
construction today include rigid foams such as extruded polystyrene
(XPS) foam, polyisocyanurate (PIR) foam, and molded polystyrene
bead (EPS) foam. These insulative foam materials, however, also
have their handicaps.
[0012] Sheathing material, such as OSB, is typically {fraction
(7/16)} inches (11.1 mm) thick, allowing for only 0.125 inch (3.2
mm) in additional insulative foam thickness in order to maintain a
standard wall thickness in typical wall construction. Rigid
insulating foam, such as XPS, PIR and EPS tend to be fragile and
offer minimal insulative value at such a small thickness. Often, a
rigid insulative foam includes a facer sheet (e.g., polymeric film,
glass fiber mat, or paper) on one or both opposing primary face(s)
in order to enhance the foam's structural integrity. Such facer
sheets tend to hinder water vapor permeability through a foam,
which can result in increased moisture near a sheathing material.
Thicker rigid insulating foams are more durable and offer better
thermal insulation, but increase a wall's thickness beyond a
standard thickness, resulting in a need for windows and doors that
have jamb extensions.
[0013] EPS insulative foam has an added handicap in that it tends
to absorb water more readily than other foams. Retaining moisture
in an insulative foam undesirably increases the thermal
conductivity through the foam and can accelerate degradation of
adjacent sheathing material.
[0014] An insulated building structure comprising a polymeric
insulating foam that is sufficiently flexible to allow it to be
transported as roll stock, yet sufficiently strong to minimize,
preferably eliminate, foam breakage during transport and
installation is desirable for use as an insulative foam between
sheathing material and exterior coverage in an insulated building
structure. Such foam needs no facer, and preferably does not have a
facer.
BRIEF SUMMARY OF THE INVENTION
[0015] The present invention addresses a need in the building
industry by providing both an insulated building structure and a
method for fabricating an insulated building structure with a
strong, flexible and compressible polymeric insulating foam ("CPI
foam"), preferably a CPI foam that has no facer material adhesively
bonded, or otherwise operatively attached, to either of its
opposing primary faces.
[0016] In a first aspect, the present invention is an insulated
building structure comprising a support structure, a sheathing
material, and a CPI foam, wherein the support structure and the
sheathing material each have opposing inner and outer surfaces with
the inner surface of the sheathing material attached to the outer
surface of the support structure, and wherein the CPI foam has
opposing major surfaces with one major surface contacting the outer
surface of the sheathing material, said CPI foam having a solid
polymer matrix phase comprising a polymer resin containing
polymerized propylene monomers, said CPI foam also having: a) a
thickness of greater than 0.125 inches (in) (3.2 mm) and 0.75 in
(19.0 mm)or less; b) a compressive strength at 10% compression of
10 pounds per square inch (psi) (68.9 kilopascals (kPa)) or less,
according to American Society for Testing and Materials (ASTM)
method D3575-00-D; and c) a water pick-up of less than 5% by both
submersion testing (ASTM D3575-00L) and freeze/thaw testing (ASTM
C666-97, 25 cycles).
[0017] In a second aspect, the present invention is a method for
fabricating the insulated building structure of the first aspect,
said method comprising the steps: (a) providing a support framework
that has opposing inner and outer surfaces; (b) placing a sheathing
material that has opposing inner and outer surfaces in operative
contact with the support structure such that the inner surface of
the sheathing material contacts at least surface portions of the
support structure outer surface and attaching the sheathing
material to the outer surface of the support structure; (c)
securing a CPI foam to the outer surface of the sheathing material
so that a major surface of the CPI foam contacts the outer surface
of the sheathing material, wherein the CPI foam has a solid polymer
matrix phase comprising a polymer resin containing polymerized
propylene monomers, the CPI foam also having: (i) a thickness of
greater than 0.125 in (3.2 mm) and 0.75 in (19.0 mm) or less; (ii)
a compressive strength at 10% compression of 10 psi (68.9 kPa) or
less, according to ASTM method D3575-00-D; and (iii) a water
pick-up of less than 5% by both submersion testing (ASTM D3575-00L)
and freeze/thaw testing (ASTM C666-97, 25 cycles).
[0018] "Securing", as used herein, means attaching by way of
fasteners, such as screws or nails or construction fasteners, or
adhesives, or both fasteners and adhesives.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a portion of an insulated structure.
[0020] FIGS. 2A-2C shows portions of CPI foam.
[0021] FIGS. 3A and 3B shows a typical window for new construction
and replacement installation, respectively.
[0022] FIG. 3C shows a cross-sectional view of a typical window for
new construction in an insulated building structure of the present
invention.
[0023] FIGS. 4A and 4B show a replacement window having a U-shaped
frame.
[0024] FIG. 4C shows a cross-sectional view of a replacement window
with a U-shaped frame in an insulated building structure of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 shows a portion of insulated building structure 10,
an example of an insulated building of the present invention.
Structure 10 comprises, in part, support framework 20, which, in
turn, comprises a plurality of interconnected support framework
members 23 and has an inside surface 25 and an outer surface 27.
Structure 10 also comprises sheathing material 40 that has an inner
surface 43 and an outer surface 45. Construction adhesive 30 (shown
as discrete aliquots, but continuous beads of adhesive may also be
used) attaches inner surface 43 of sheathing material 40 to outer
surface 27 of support framework 20. Construction fasteners 50 hold
major surface 65 (not shown) of CPI foam 60 against outer surface
45 of sheathing material 40.
[0026] "Interior", "inside" and "inner" may be used
interchangeably. Similarly, "exterior", "outside" and "outer" may
be used interchangeably.
[0027] The insulated building structures of the present invention
are not limited to a particular support structure or sheathing
material. Support structures are well known in the field of
building construction and serve to define a foundation for, e.g.,
walls, floors and ceilings of a structure. Examples of typical
support structures include frameworks comprising wooden boards,
metal beams, girders, polymer composite "boards", or any
combination thereof. Other support structures can include cement
block or brick. Support structures encompass an interior space,
such as the interior of a house. An interior space is considered as
being inside of a structure. Support structures have opposing
interior and an exterior surfaces, with the interior surface most
proximate to an interior space encompassed by the support
structure.
[0028] Sheathing materials attach to at least a portion of an
exterior surface of a support structure. Sheathing materials have
opposing inner and outer surfaces. The inner surface of a sheathing
material attaches to the exterior surface of a support structure.
Sheathing material can serve multiple purposes. To some extent,
sheathing material acts as an air barrier between the inside and
outside of a structure. Usually, sheathing material also enhances a
support structure's strength and stability. Examples of sheathing
materials include OSB, plywood and rigid polymeric foam insulation
(e.g., XPS foam board), with OSB being perhaps the most common.
[0029] The insulated building structures of the present invention
also comprise a CPI foam. The CPI foam has opposing major surfaces,
one of which contacts the outer surface of the sheathing material.
The CPI foam has a solid polymer matrix phase that comprises a
polymer resin containing polymerized propylene monomer units. For
example, the polymer resin can comprise a propylene homopolymer, a
propylene copolymer, a blend of a propylene homopolymer and a
propylene copolymer or a blend two or more propylene copolymers.
The resin can comprise a blend of different polymers, provided the
polymers are suitably compatible such that the blend can form a
foam and provided at least one of the polymers has polymerized
propylene monomer units. Desirably, at least 50 weight-percent (wt
%) of the polymer resin, preferably greater than 50 wt %, more
preferably 60 wt % or more by weight of the polymer resin is
polymerized propylene units. Polymerized propylene units are
desirable in a polymer resin, e.g., to increase the resin's thermal
stability. Generally, though not necessarily, the CPI foam
comprises multiple distinguishable coalesced foam strands.
[0030] CPI foam for use in the present invention desirably has a
thickness of 0.125 in (3.2 mm) or more, preferably 0.25 in (6.4 mm)
or more, and 0.75 in (19 mm) or less. A particularly desirable CPI
foam has a thickness of 0.5 in (12.7 mm). CPI foam thickness is a
distance or span measured between opposing major surfaces.
[0031] CPI foam for use in the present invention further desirably
has a compressive strength at 10% compression of 10 psi (68.9 kPa)
or less according to ASTM method D3575-00-D; and a water pick up of
less than 5%, preferably less than 3%, more preferably less than
1.5%, most preferably less than 1% by both submersion (ASTM method
D3575-00L) and freeze/thaw (ASTM method C666-97, with 25 cycles)
test methods.
[0032] A CPI foam having these desirable properties is particularly
useful in building construction as an insulating component between
a sheathing material and exterior coverage such as aluminum or
vinyl siding. Such a compressive strength may allow enough
compression of a CPI foam by a window or door frame to minimize and
preferably eliminate a need for jamb extensions, particularly with
CPI foam compressive strength values well below 10 psi, such as 1
to 2 psi (6.9 to 13.8 kPa), in conjunction with proper selection of
fastening means that hold the CPI foam in a compressed state. In
addition, water pick up of less than 5% hinders retention of water
near a sheathing material.
[0033] CPI foams suitable for use in the present invention have a
thickness that is sufficient to provide a desirable decrease in
thermal conductivity through a wall structure. The CPI foams are
preferably not so thick as to require extensive use of jamb
extensions for window and door installation. Foams thicker than
0.125 in (3.2 mm) offer higher thermal insulation values than
similar foams that are not as thick (e.g. foams having a thickness
of 0.05 in (1.3 mm)).
[0034] The CPI foam is compressible between a sheathing material of
a wall and a portion of window frame or a portion of doorframe
and/or trim. Herein, "frame" and "jamb" are interchangeable and
refer to a combination of header (top), sill (bottom) and sides of
a window or door framework. Compressing a portion of CPI foam
around window frames and door frames creates a seal around the
windows and doors, enhancing insulation of the building structure
that contains such window frames and door frames. Furthermore,
compressing a portion of CPI foam between a window or door frame
and a sheathing material allows for the use of thicker foams (i.e.,
greater than 1/8 inch (3.18 mm)) without requiring jamb extensions.
Thicker foam is desirable in order to increase a wall's thermal
insulation character. CPI foam desirably conforms to dimensional
irregularities in wall thickness around windows and doors allowing
for a more uniform seal around windows and doors than one can
attain with a substantially incompressible foam (e.g. a foam with a
compressive strength well in excess of 10 psi (68.9 kPa), such as
100 psi (689 kPa)).
[0035] CPI foams for use in the present invention preferably have a
density of 0.5 pounds per cubic foot (pcf) or more (eight kilograms
per cubic meter (kg/m.sup.3) or more) and two pcf (32 kg/m.sup.3)
or less, more preferably 1.5 pcf (24 kg/m.sup.3) or less. Determine
foam density according to ASTM method D3575-93W. CPI foams having a
density below 0.5 pcf (eight kg/m.sup.3) tend to have insufficient
stiffness, flopping undesirably during handling. CPI foams having a
density above two pcf (32 kg/m.sup.3) tend to have an undesirably
high thermal conductivity.
[0036] Desirably, CPI foams of the present invention have a thermal
conductivity of 0.28 British Thermal Units-inch per degree
Fahrenheit-square foot-hour (BTU-in/.degree. F.-ft.sup.2-hr) or
less (40 milliwatts per meter-Kelvin (mW/m-K) or less) according to
ASTM method D3575. A CPI foam for use in the present invention
typically has a cell size of 1.5 mm or less and preferably one mm
or less, as determined by ASTM method D3576.
[0037] CPI foam for use in the present invention advantageously is
flexible enough to bend around a one-inch (25.4 mm) diameter
mandrel without breaking. At the same time, the CPI foam is
advantageously sufficiently rigid so that it has a deflection angle
of less than 75 degrees (.degree.), preferably 60.degree. or less,
more preferably 45.degree. or less, still more preferably
30.degree. or less, even more preferably 15.degree. or less in a
Horizontal Bend Test. Conceivably, CPI foam for use in the present
invention can have a deflection angle of 0.degree. in a Horizontal
Bend Test.
[0038] To conduct a Horizontal Bend Test, place a major surface of
a CPI foam having a length of at least four feet (1.2 meter (m)),
preferably eight feet (2.4 m) and a width of two feet (0.6 m) on a
horizontal support surface (e.g., a table top). The length and
width define the CPI foam's major surface. Position the CPI foam
such that three feet (0.914 m) of the CPI foam's length extends
unsupported off from an edge of the horizontal support surface
while holding the remaining length of CPI foam against the
horizontal support surface, particularly at the edge of the
horizontal support surface. Measure the deflection angle of the
unsupported length of CPI foam. The deflection angle is an angle
between a straight line from the unsupported end of the CPI foam to
the edge of the horizontal support surface and a line corresponding
to position the unsupported portion of CPI foam would make if it
did not bend. Flexibility is desirable because it renders a CPI
foam less likely to break or fracture during handling while the
specified level of rigidity allows for easy handling and
installation of the CPI foam, even by an individual installer.
[0039] Too much flexibility can be undesirable. For example,
commercially available polyethylene foams that are less than 0.75
inches (19 mm) thick tend to be sufficiently flexible (floppy) so
as to have a deflection angle of more than 45.degree. in the
Horizontal Bend Test. As a result, these polyethylene foams are
difficult to handle and install, particularly by an individual
installer.
[0040] CPI foams for use in the present invention desirably have an
open cell content of 20% or more, preferably 30% or more, still
more preferably 40% or more and up to and including 100% open cell
content. Measure open cell content according to ASTM method
2856-94.
[0041] Insulated building structures in colder climates generally
benefit from CPI foams having a higher water vapor permeability
than insulated building structures in warmer climates. CPI foams
for use in the present invention desirably have a water vapor
permeability of one or more perms, preferably five or more perms,
more preferably 70 g/m.sup.2-24 hr (10 or more perms) and
preferably 140 grams per square meter per 24 hours (g/m.sup.2-24
hr) (20 or less U.S. perm units or perms) according to ASTM method
E96-00. A CPI foam having 105 g/m.sup.2-24 hr (15 perms) is
particularly desirable. A CPI foam that has a water vapor
permeability of less than 7 g/m.sup.2-24 hr (one perm) tends to
prevent moisture from escaping through it and may allow water
build-up adjacent to sheathing material, unless air flow is present
by means of, e.g., grooves in the CPI foam. A CPI foam may contain
multiple perforations that enhance water vapor permeability.
Interestingly, the perforations can either extend through the CPI
foam (penetrating through opposing surfaces) or penetrate into a
CPI foam without extending through the CPI foam (i.e., penetrating
through only one surface) and still enhance water vapor
permeability. A water vapor permeability below 140 g/m.sup.2-24 hr
(20 perms) is desirable so the CPI foam will have a desirable air
flow resistivity.
[0042] Desirably, the CPI foam has an air flow resistivity of less
than 25 kilopascal-seconds per square meter. Having a low air flow
resistivity is desirably to enhance isolation of a building's
interior environment from its exterior environment.
[0043] CPI foams for use in the present invention can contain
indentations in the form of, e.g., grooves and channels along one
or more surface. Indentations penetrate into a surface, preferably
a major surface, of the CPI foam to a depth less than the thickness
of the CPI foam and desirably traverse a surface of the CPI foam.
Traversing a surface means extending from one edge of a CPI foam to
an opposing edge of that CPI foam. Accordingly, the indentations
can extend, e.g., entirely along the CPI foam's length, across the
CPI foam's width, or diagonally across a CPI foam's surface. The
indentations may be straight lines or take on any other regular or
irregular path so long as one end of the path intersects with one
edge of a CPI foam and the other end of the path intersects with a
different edge, preferably an opposing, but spaced apart, edge, of
the CPI foam. As an example, a CPI foam can contain a series of
regular parallel grooves that traverse one of its surfaces.
Alternatively, a CPI foam can have raised portions, e.g., inverted
dimples or small bumps along one or more surface. Upon placing such
a CPI foam against a sheathing material such that a side with
indentations or raised portions is adjacent to the sheathing
material, one creates channels or pathways that facilitate fluid
communication, or air flow, from one CPI foam edge to another edge
of the same CPI foam. In such an orientation air can circulate
along at least portions of the interface between the CPI foam and
the sheathing material. Such air circulation can be desirable to
enhance removal of any moisture that may otherwise accumulate at
the interface or in the sheathing or CPI foam.
[0044] U.S. Pat. No. 6,583,193 (incorporated herein by reference)
discloses a foam suitable for use as a CPI foam in insulated
building structures of the present invention and its preparation.
The CPI foam is an extruded, coalesced foam strand material made
from a polymer composition that comprises a linear polyolefin resin
or blend of a linear polyolefin resin, particularly propylene
polymers. CPI foams made according to the teachings of U.S. Pat.
No. 6,583,199 are especially desirable and such foams that meet one
or more of the preferred embodiments described herein are
preferred. Coalesced foam strand materials can advantageously have
grooves along their major surfaces at points where strands meet, as
described below.
[0045] While coalesced foam strand materials serve as preferable
CPI foam materials, a skilled artisan recognizes that the CPI foam
can also be free of coalesced foam strands, e.g., a coalesced foam
bead structure, an extruded sheet material, a laminated sheet
material, or a combination of any of these foams with coalesced
foam strands. A skilled artisan can prepare such foam materials by
standard, well known foam manufacturing methods.
[0046] While CPI foams that are suitable for use in the insulated
building structures of the present invention preferably do not have
a facer material for various reasons, such as cost, ease of
fabrication and enhanced water vapor permeability, one can include
facer materials (e.g., polymeric films, glass fibers, and paper) on
one or both major surface(s) of the CPI foam without departing from
the scope of the present invention.
[0047] FIGS. 2A, 2B, and 2C show portions of CPI foams suitable for
use in the present invention. FIG. 2A shows CPI foam 100 comprising
multiple distinguishable polymeric foam strands 110 and containing
multiple regularly spaced perforations 120 through major surface
130. FIG. 2B shows CPI foam 200 comprising multiple polymeric foam
strands 210. Major surface 230 contains regularly spaced grooves
220 where foam strands 210 meet. FIG. 2C shows CPI foam 300
comprising multiple polymeric foam strands 310 and containing
multiple grooves 320 that extend through major surface 330 but to a
depth less than the thickness D of CPI foam 300.
[0048] Insulated building structures of the present invention
comprise a support framework with an inner surface of a sheathing
material attached to the outer surface of the support framework and
a CPI foam contacting an outer surface of the sheathing material.
The insulated building structure can further comprise one or more
window, one or more door, or a combination of one or more window
and one or more door. The present insulated building structure
contains at least one wall that contains the polymeric insulating
foam, sheathing material and a support framework.
[0049] FIGS. 3A, 3B, 3C and 4A, 4B and 4C generally illustrate two
types of windows suitable for use in the present invention.
[0050] FIGS. 3A and 3B illustrate a face and side view,
respectively, of window 200 that is typical for use in original
construction. Window 200 includes frame (jamb) 210 with nail flange
220. FIG. 3C illustrates a cross-sectional view of window 200
installed in wall 230. Wall 230 contains CPI foam 240, sheathing
material 250, support framework 260, and drywall 270. Desirably,
when using a window such as 200 that has a nail flange such as 220
in the present invention, position window 200 such that CPI foam
240 is between nail flange 220 and sheathing material 250. Nail
flange 220 desirably compresses the CPI foam sufficiently to as to
eliminate a need for a window with extension jambs.
[0051] The compressibility of the CPI foam allows for CPI foam
thicknesses of 0.5 inches (12.7 mm) or thicker without requiring
windows with extension jambs, even if the wall has irregularities
in its thickness. Furthermore, compressing the CPI foam between the
nail flange 220 and a sheathing material has a gasketing effect
that works as a seal around window 200.
[0052] FIGS. 4A and 4B illustrate a face and side view,
respectively, of window 300 that is one type of replacement window.
Window 300 differs from window 200 by having U-shaped frame 310
instead of a nail flange. U-shaped frame 310 has a width D that
corresponds to a wall width. A polymeric insulating foam, sheathing
material and support framework all fit between lips 320 and 330 of
window 300 upon installing window 300 within the scope of the
present invention. FIG. 4C shows a cross-sectional view of window
300 installed in wall 340, which contains support structure 350,
sheathing material 360, CPI foam 370, and drywall 380. FIG. 4C
shows how lip 320 can compress CPI foam 370 against sheathing
material 360. Polymeric insulative foam 370 can have a thickness of
greater than 0.5 inches (12.7 mm) to provide additional thermal
insulation to wall 340 without requiring window 300 to have an
extension jamb.
[0053] The present invention is also compatible with other types of
windows, provided some portion of the window frame or even window
trim, compresses a CPI foam between itself and a sheathing
material. For example, replacement windows can also have an
attachable nail flange that can be useful for compressing a CPI
foam.
[0054] Door frames, once installed, have a similar cross-sectional
view as window 300 in FIG. 4C except instead of lips 320 and 330 a
door frame has trim around the door. Trim can compress a CPI foam
of the present invention between itself and sheathing material in
order to allow CPI foam thicknesses of greater than 0.5 inches
(12.7 mm) without require door jamb extensions.
[0055] While the FIGS. 3C and 4C illustrate CPI foam compressing
directly against sheathing material, a skilled artisan realizes
that other materials such as a house wrap may reside between the
CPI foam and sheathing material within the scope of the present
invention. Similarly, a house wrap material may reside against the
CPI foam on a foam surface remote from the sheathing material while
within the scope of the present invention.
[0056] In general, fabrication of insulated building structures of
the present invention begins with provision of a support framework
and a sheathing material, each of which has opposing inner and
outer surfaces, and a CPI foam of the type described herein with
opposing major surfaces. Fabrication continues with a step of
attaching the inner surface of the sheathing material to the outer
surface of the support structure. In a subsequent step, fabrication
proceeds with applying the CPI foam to the outer surface of the
sheathing material so that a major surface of the foam contacts the
outer surface of the sheathing material. Affixing or attaching the
CPI foam to the sheathing material is acceptable and beneficial to
hold the foam in place prior to and during installation of any
exterior coverage. Construction adhesives such as glue and caulk as
well as construction fasteners such as screws, nails, and staples
are suitable for affixing or attaching the foam to sheathing
material, as well as for attaching sheathing material to a support
framework.
[0057] A typical installation involves first attaching multiple
sheets of sheathing material to an outer surface of a support
framework, butting adjacent sheets of sheathing material against
one another. Installation continues with application of multiple
sheets of CPI foam to the sheathing material. Position the CPI foam
sheets adjacent to, and butting against, one another and,
preferably, place tape over seams between sheets to seal the seams
and minimize, preferably eliminate, air penetration via the seams.
An especially preferred installation technique, staggers the
position of CPI foam sheets relative to sheathing material sheets
such that seams between sheets of sheathing material do not align
with seams between sheets of CPI foam.
[0058] In general, installation of windows and doors occurs after
application of CPI foam sheets to the sheathing material. In one
embodiment, follow application of CPI foam sheets to the sheathing
material by cutting one or more opening(s) through the CPI foam and
sheathing material of appropriate size to receive a window or door,
according to opening dimensions specified by the window or door
manufacture. Alternatively, provide the necessary opening(s) in the
CPI foam and sheathing material and then apply the CPI foam to the
sheathing material while aligning the holes in the CPI foam with
the holes in the sheathing material. Install window(s) and door(s)
through the appropriate opening. Desirably, window frame or door
trim compress a portion of the CPI foam between itself and the
sheathing material, thereby forming a seal around the window and/or
door.
[0059] In an alternative embodiment, install window and doors
through sheathing material prior to applying CPI foam to the
sheathing material. Within such an embodiment, tuck and compress a
portion of the CPI foam between window frames and doorframes or
trim and sheathing material.
[0060] Applying CPI foam to sheathing material prior to attaching
sheathing material to a support structure is acceptable and can
advantageously speed fabrication of an insulated building structure
by allowing both sheathing and foam to be applied simultaneously to
a support framework. As a particularly desirable example, apply a
CPI foam sheet to a sheet of sheathing material that is of similar
dimensions, but with the CPI foam offset so as to extend past an
edge of the sheet of sheathing material. Within such an
orientation, a portion of the sheathing material's outer surface
along one or two of its edges remains uncovered by the CPI foam
while a portion of CPI foam extends past an opposing edge of the
sheathing material. When attaching these offset combinations of CPI
foam and sheathing material to a support structure, orient them so
that the portion of CPI foam that extends past or overhangs one
combination overlaps the exposed portion of outer surface on an
adjacent sheathing material. In this manner, CPI foam seals over
joints between sheets of sheathing material. This type of joint
overlap is also advantageous when applying CPI foam to sheathing
material that is already attached to a support structure. Sheets of
CPI foam and sheathing material can also be aligned with one
another to form a single laminate sheet. Application of such
laminate sheets results in less desirable, but still acceptable for
purposes of the present invention, coinciding seams for foam and
sheathing material.
[0061] The following examples provide further illustration of the
present invention.
[0062] CPI Foam
[0063] Prepare or acquire a CPI foam that comprises a polymer resin
containing 86 weight-percent (wt %) propylene monomer units and 14
wt % ethylene monomer units. The CPI foam has a density of 1 pcf
(16 kg/m.sup.3), 0.6 mm average cell size, an open cell content of
40% (ASTM method 2856-94), a compressive strength at 10%
compression of 4 psi (27.6 kPa), a water pick up of 0.2% by ASTM
method D3575-00L and 0.9% by ASTM method C666-97. The CPI foam
contains sufficient carbon black to achieve a thermal conductivity
of 0.2377 BTU-inch/.degree. F.-ft.sup.2-hr (34.3 mW/m-K) (ASTM
method D-3575-00). The CPI foam is sufficiently flexible to bend
around a one-inch (25.4 mm) diameter mandrel without breaking yet
has a deflection angle in the Horizontal bend Test of less than
45.degree.. Such a CPI foam is available from The Dow Chemical
Company as extruded polypropylene foam XU52024.00.
[0064] Fabricating an Insulated Building Structure
EXAMPLE ONE
[0065] Provide a standard timber support framework of nominal
2.times.4 (1.75 in by 3.5 in (4.4 cm by 8.9 cm) lumber and attach 4
foot (1.22 m) by 8 foot (2.44 m) by {fraction (7/16)} inch (11.1
mm) sheets of OSB over the outer surface of the framework. Attach
the OSB to the framework using standard construction nails or
screws. Over the OSB apply 4 foot (1.22 m) by 8 foot (2.44 m) by
0.5 inch (12.7 mm) sheets of the above CPI foam, positioned so that
seams between CPI foam sheets do not overlap with seams between
adjacent OSB sheets. Affix the sheets of CPI foam to the OSB using
plastic cap nails, preferably spaced 16 in (0.41 m) apart. Tape
over all seams between adjacent CPI foam sheets using a contractor
grade tape such as 3M Contractor Sheathing Tape No. 8086.
[0066] Install windows and doors according to manufacturer's
recommendations. Desirably, compress the CPI foam slightly with
window frames and door trim. Flash windows and doors according to
building code requirements. When using 0.5 inch (12.7 mm) drywall
to finish the inner surface of the support framework, jamb
extensions are not necessary for the windows or doors.
[0067] Example One illustrates an insulated building structure of
the present invention comprising a CPI foam over a sheathing
material attached to a support framework.
EXAMPLE TWO
[0068] Prepare an insulated building structure as per Example One
except use a polymeric insulating foam having a thickness of 0.6
inches (15.24 mm). Compress the foam with window and doorframes or
trim sufficiently to preclude need for jamb extensions in the
windows and doors.
[0069] Example two illustrates an insulated building structure and
a method of fabricated an insulated building structure using a
compressible polymeric insulating foam having a thickness of
greater than 0.5 inches (12.7 mm) over a sheathing material wherein
the building structure accommodates windows and doors without
requires jamb extensions.
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