Note: Descriptions are shown in the official language in which they were submitted.
CA 02688139 2009-12-07
FLEXIBLE FLASHING MATERIAL AND METHOD OF MANUFACTURE
BACKGROUND OF THE INVENTION
The present invention relates to waterproofing a building structure, such as a
building opening, a deck ledger or joist, a corner of an exterior wall, a roof-
to-wall
interface, a through-wall passage, or the like, and more particularly, the
present invention
relates to a flexible drainage-promoting flashing material and its method of
manufacture.
By way of example, water leakage or seepage can occur through the joints of a
window and/or window frame, and moisture infiltration within and around a
window
opening in a wall can be caused by blowing rain, melting snow or ice, and/or
condensation of moisture vapor. Similar leakage and/or seepage can also occur
via
through-wall passages and other building openings, behind deck ledger boards,
within a
corner of an exterior wall or wall-to-roof interface, or at other areas of a
building
structure. Moisture that infiltrates these areas will likely become trapped
within the
building structure and over time will cause structural damage such as rotting
of
windowsills, framing elements, legers and joists, adjacent wall or roof
sheathing and
studs, and exterior sidewall and trim building materials. In addition, trapped
moisture
will also cause the undesired growth of mold within the wall or adjacent
structure.
For purposes of preventing such damage with respect to window openings, it is
conventional practice to install a sill pan or like flashing material to a
window opening
before a window is installed within the opening. The sill pan or like flashing
material
provides a water impermeable layer of material that prevents any moisture,
which may
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infiltrate the opening, from contacting the generally wooden framework members
of the
sill and like surfaces within the wall. Preferably, the sill pan or flashing
material should
also permit and/or promote removal of moisture from the sill area to an area
on an
exterior side of the building envelope. Thus, the sill pan and flashing is
used to prevent
structural damage of the building structure about the window opening, drain
moisture to
an exterior of the building, and lessen the likelihood of mold forming within
the walls of
the structure.
By way of example, the following U.S. patents and U.S. published applications
disclose various known sill pans, sill drainage systems, flashing, and like
building
materials: U.S. Application Publication Nos. 2008/0105363 Al of Ford,
2008/0010917
Al of Hopkins et al., 2006/0101726 Al of Collins, 2005/0217189 Al of Moffit,
2008/0178557 Al of Parsons et al., 2006/0010788 Al of Nettleton, 2007/0289226
Al of
Lokkart, 2006/0236618 Al of Williams, 2006/0137263 Al of Casey, 2003/0056444
Al
of Ackerman, Jr., 2003/0177727 Al of Gatherum, 2006/0143994 Al of Allen,
2007/0157528 Al of Gawoski and 2005/0144856 Al of Conlin and U.S. Patent Nos.
6,676,779 B2 issued to Hopkins et al., 7,201,820 B2 issued to Wiercinski,
6,964,136 B2
issued to Collins et al., 1,677,130 issued to Cherry, 4,555,882 issued to
Moffit et al.,
7,222,462 B2 issued to Ellingson, 6,385,925 B1 issued to Wark, 5,822,933 and
5,921,038
issued to Burroughs et al., 7,367,164 B2 issued to Burton et al., 7,134,245 B2
issued to
Burton, 6,401,402 and 6,401,401 issued to Williams, 6,725,610 B2 issued to
Murphy et
al, 6,305,130 B 1 issued to Ackerman, Jr., and 7,059,087 B2 and 7,290,379 B2
issued to
Allen.
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Although the sill pans, flashing materials, assemblies, and methods disclosed
in
the above referenced patents and published applications may be satisfactory
for their
intended purpose, there is a need for an improved building material and method
for
waterproofing internal components of a through-wall opening or the like of a
structure,
wall corners, wall-to-roof interface areas, deck ledgers and joists and like
structures and
for removing moisture that penetrates into such openings or structures. The
building
material should be inexpensive to manufacture and require only a minimum of
skill and
labor to apply within an opening or on a structure.
SUMMARY OF THE INVENTION
A flashing material for a building structure is provided. The flashing
material
includes a water-resistive membrane sufficiently flexible to conform to
underlying
surfaces and a series of separate, laterally spaced-apart, elongate spacers
bonded to an
upper surface of the membrane. The elongate spacers are polymeric filaments
and define
an air space and drainage paths across the upper surface of the membrane.
The filaments are of a thickness that projects to a predetermined height above
the
upper surface of the membrane and that defines a thickness of the air space
above the
upper face of the membrane. The filaments have a series of depressions formed
therein
that do not extend to the predetermined height and that provide drainage paths
in a
direction transversely across the filaments. According to one contemplated
embodiment
of the present invention, the series of depressions are located at spaced
intervals along a
length of each filament and are formed by flattened sections of the filaments,
and each
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filament is continuous and consists of an alternating array of the flattened
sections and
non-flattened full-size sections of the filament.
The membrane can be of multi-layer construction including an upper layer of
polymeric material to which the filaments are bonded and a lower integral
layer of
adhesive providing an underside of the membrane. A release sheet can be used
to cover
the adhesive whereby the layer of adhesive can be exposed when the release
sheet is
removed from the membrane. Alternatively, the membrane can be provided without
an
adhesive layer and release sheet. In addition, an elongate flexible wedge can
be secured
to a rear edge portion of the underside of the membrane to provide the
membrane with a
forward slope from its rear edge toward its front edge. Alternatively, the
membrane can
be provided without the integral wedge component.
According to another aspect of the present invention, an assembly of a window,
door, or like opening of a building is provided. The assembly includes
framework
defining an opening in an exterior wall of a building. The framework includes
a sill
member extending between opposite upright framing members. The assembly also
includes an outer sheathing member applied to the wall below the opening. A
flexible
water-resistive membrane is applied over the sill member and is folded over a
front edge
of the opening and extends on the outer sheathing member. The membrane has a
series
of separate, laterally spaced-apart, elongate spacers bonded to an upper
surface of the
membrane, and the elongate spacers are polymeric filaments that define an air
space and
drainage paths across the upper surface of the membrane. Each of the filaments
extends
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generally in a direction from one of the upright framing members to the
opposite one of
the upright framing members along the length of the sill member of the
opening.
As discussed above, the filaments are of a thickness that projects to a
predetermined height above the upper surface of the membrane and that defines
a
thickness of the air space above the upper face of the membrane, and the
filaments have a
series of depressions formed therein that do not extend to the predetermined
height. The
depressions provide the drainage paths which extend transversely across the
filaments.
Preferably, the series of depressions are located at spaced intervals along a
length of each
filament and are formed by flattened sections of the filaments, and each
filament is
continuous and consists of an alternating array of the flattened sections and
non-flattened
full-size sections of the filament.
The assembly can include a pre-applied layer of adhesive on the underside of
the
membrane to adhesively secure the membrane to the sill member and outer
sheathing,
and/or the assembly can include an elongate wedge or backdam secured to the
sill
member underneath a rear edge portion of the membrane to provide the membrane
with a
forward slope from its rear edge toward its front edge. In addition, the
assembly can
include a window or the like installed within the opening over the sill member
and
membrane. In this case, the air space and drainage paths are provided between
the upper
face of the membrane and lowermost framing elements of the window, including a
lower
window flange of a flanged window. In addition, the same membrane with
filament
spacers used on the sill can also be applied adjacent the jambs and header of
the opening
behind exterior window trim to promote drainage behind the trim.
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A further aspect of the present invention is directed to a method of making a
flashing material for an opening in an exterior wall of a building. A series
of separate,
laterally spaced-apart, elongate polymeric filaments are bonded on an upper
surface of a
flexible water-resistive membrane. The filaments are flattened at spaced
intervals along
their length to create drainage paths extending transversely across the
filaments. The
method can also include the steps of applying a layer of adhesive on an
underside of the
membrane and thereafter applying a release sheet to the underside of the
membrane to
cover the layer of adhesive. Further, the method can include the step of
securing a wedge
of flexible material to an underside of the membrane along a rear edge portion
of the
membrane.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. I is a front elevational view of a an exterior wall of a building having
a
window;
FIG. 2 is a partially cut-away perspective view of a flexible window sill
flashing
material according to the present invention;
FIG. 3 is a cross-sectional of the flexible flashing material along line 3-3
of FIG.
2;
FIG. 4 is a perspective view of the flexible window sill flashing material of
FIG. 2
applied to a window opening;
FIG. 5 is a cross-sectional view of a window opening and the flexible sill
flashing
material installed within the window opening;
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FIG. 6 is a perspective view of a wall on which the window and the flexible
sill
flashing material are installed before exterior trim and sidewall building
materials are
installed;
FIG. 7 is an elevational view of a wall on which the window flanges at the
header
and jambs have been covered with the flashing material according to the
present
invention; and
FIG. 8 is a perspective view of a deck ledger and joists on which a flexible
flashing material according to the present invention is applied.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a flexible membrane that can be used, for
instance, to waterproof a sill surface of framework of a window opening of a
building
structure. However, the flexible membrane is not limited to use in window
openings and
can also be used to promote drainage at other locations within or adjacent an
exterior wall
and/or roof assembly of a building. Examples include use of the flexible
membranes
about building openings such as doors or the like, other through-wall openings
such as
for conduits, pipes, wires and the like, wall corner and wall-to-roof
interfaces, and deck
ledger boards and joists.
By way of example, the flexible membrane is applied to the window opening
before the window is installed. After installation of the window and adjacent
outer
sidewall and trim building materials, the membrane is embedded within the
structure and
hidden from sight. The flexible membrane can also be utilized to promote
drainage
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behind trim elements of an opening adjacent header and jamb surfaces and to
protect the
sill surfaces of doors. Of course, the flexible membrane can also be used to
promote
drainage within a wall corner or wall-to-roof interface and about deck ledger
boards and
joists as discussed above.
According to one example, FIG. I illustrates a finished exterior wall 10 of a
building having a window 12, exterior window trim 70, and exterior siding
material 74.
Over the course of the life of the wall 10 and window 12, moisture may
infiltrate through
the joints of the window or its frame as well as through small cracks or the
like between
the wall 10 and window 12 due to blowing rain, melting snow and ice,
condensation of
moisture vapor, and the like. Moisture often collects within the sill area 14
of the wall
beneath the window 12. Accordingly, it is important to provide protection
against
moisture infiltration in the sill area 14 and to provide a drainage path for
any moisture
accumulating in the sill area 14 such that the moisture is properly directed
to ambient
atmosphere on an exterior side of the building envelope.
FIGs. 2 and 3 illustrate one contemplated embodiment of a membrane 20. The
membrane 20 has waterproofing qualities and provides a substantially
impermeable
barrier to moisture. As an example, the membrane 20 can be made of a single
sheet or
multiple layered sheets of plastic, polymeric material, elastomeric material,
rubber,
synthetic rubber, bitumen-containing material, or any other water-resistive
barrier
material that is flexible and is of a size to cover the sill area of a window
opening as
discussed below in greater detail.
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The membrane 20 can be at least slightly elastic so that it can be tightly
fitted
within and/or around corners of the window opening and can accommodate various-
shaped underlying surfaces, edges, overhangs, uneven surfaces, and the like.
Alternatively, the membrane 20 need only be flexible and not elastic.
Preferably, the
membrane 20 is sufficiently tear-resistant such that it does not tear during
installation of
the window or over the expected life of the window installation. If desired,
additional
tear-resistance can be provided by using a multilayer membrane that includes
one or
more reinforcing layers, such as a mesh reinforcing layer.
When the membrane 20 is applied to a window opening, it will typically be
applied over a sloped sill area with a backdam or the like that prevents
undesired flow of
moisture on the sill toward the inside of the building. In some contemplated
embodiments of the present invention, a wedge 22 of material is pre-applied,
adhered,
bonded, or otherwise secured to a rear portion 24 of the underside 26 of the
membrane
20. See FIG. 2. Alternatively, the wedge 22 or some other type of backdam can
be
applied separately to the window opening, and the membrane 20 can thereafter
be applied
over the wedge or backdam at the building site.
The embodiment of FIG. 2 integrates the wedge 22, or backdam, directly on the
membrane 20 and, as illustrated, the wedge 22 provides a forward-directed
slope between
its front and rear edges to provide a forward-sloped surface along the width
of the wedge
material 22. Thus, the wedge 22 elevates the rear portion 24 of the membrane
20 when
the membrane 20 is applied to a substantially horizontally-disposed sill
surface.
Accordingly, any moisture collected on an upper surface 28 of the membrane 20
will be
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directed by the force of gravity toward and off the front edge of the sill and
onto a water-
resistive barrier (not shown) applied on and covering the wall sheathing
adjacent the
window opening.
The wedge 22 can be made of any material having sufficient structural rigidity
to
maintain the rear portion 24 of the membrane 20 elevated when a structure
(e.g., door or
window) is installed on top of the membrane 20. Such material may include,
without
limitation, plastics, closed cell foams, and open celled foams. Another
contemplated
material is an openwork mat of polymeric filaments. It is desirable that the
wedge 22 be
formed of a flexible material such that the resulting membrane 20 is flexible
for purposes
of ease of installation.
In some contemplated embodiments of the present invention, the membrane can
be formed of multiple layers. The upper surface 28 can be formed by a
waterproof non-
woven sheet layer such as known for use with respect to housewrap materials.
The
underside 26 of the membrane 20 can be provided by a separate waterproof
adhesive
layer that bonds to the upper layer and that is used to bond the membrane 20
directly to
the surface of the underlying sill to which the membrane is applied. The
adhesive layer
eliminates the need for nails, staples or like fasteners to pierce the
membrane 20 or the
use of a separately applied layer of adhesive or sealant. As an alternative,
the membrane
can be provided without an adhesive layer and can be secured to the sill with
fasteners,
tape, adhesives, or the like.
The membrane 20 illustrated in FIGs. 2 and 3 includes an adhesive layer, and
therefore, also includes a release sheet 30 that is removably bonded to the
adhesive
CA 02688139 2009-12-07
underside 26 of the membrane 20. Thus, the membrane 20 can be a peel-and-stick
type
of product. Removal of the release sheet 30 exposes the adhesive nature of the
underside
26 of the membrane 20 and permits the membrane 20 to be adhered to a desired
surface
enabling ready installation. As examples, the flexible release sheet 30 can be
made of
foils, metals, plastics, or papers treated with silicon or other substances to
provide a low
level of adhesion to the underlying adhesive layer 26 of the membrane 20. In
addition,
the single or multi-layer membrane 20, optional wedge material 22, and release
sheet 30
all should be capable of being readily cut thereby enabling the membrane to be
cut to size
to fit window openings of any dimension. Alternatively, the membrane 20 can be
provided in various standard sizes of window openings to avoid a cutting step.
The upper surface 28 of the flexible membrane 20 according to the present
invention carries a series of spacing elements 32 that ensure the presence of
a small air
space between the upper surface 28 of the membrane 20 and any other materials,
such as
the window frame or the like, applied over the membrane 20. The spacing
elements 32
also provide drainage paths on the upper surface 28 enabling moisture to drain
forward
on the membrane 20 and over the front edge of the sill area thereby preventing
moisture
from accumulating long term in the sill area.
As best illustrated in FIGs. 2 and 3, the spacer elements 32 on the upper
surface
28 of the membrane 20 are provided as a series of separate, laterally spaced-
apart,
elongate spacer elements that are bonded, adhered, or otherwise integrally
secured to the
upper surface 28. Preferably, the elongate spacer elements 32 are thermally
bonded to
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the membrane 20 at spaced intervals; alternatively, the elements 32 can be
thermally
bonded to the membrane 20 continuously along their full length.
According to one contemplated embodiment of the present invention, the spacer
elements 32 are filaments 34, such as continuous extruded polymeric filaments.
Each
filament 34 is bonded to the upper surface 28 of the membrane 12 where it
contacts the
membrane 20 and extends in a generally longitudinal direction generally
following the
direction of the front and rear edges, 36 and 38, of the membrane. Thus, when
the
membrane 20 is installed within a window opening, the filaments 34 extend
generally
along the longitudinal axis and front and rear edges of the windowsill and the
longitudinal axis of the backdam or wedge 22. As an example, see FIG. 4.
In the illustrated embodiment, the filaments 34 are laterally and uniformly
spaced-
apart, do not intersect, and generally extend in a wavy, undulating,
serpentine or sinuous
pattern. However, they can also extend substantially parallel to each other
following a
straighter path. Alternatively, the filaments 34 of the present invention can
extend in
non-linear, saw tooth, and/or random paths or the like and can intersect
and/or cross at
random locations or at uniform spaced intervals.
As best illustrated in FIG. 5, each filament 34 can have a substantially
circular
cross-section of a predetermined diameter "D". Of course, other cross-
sectional shapes
can be utilized, such as square, rectangular, oval and triangular filament
cross-sections.
Accordingly, each filament 34 projects a distance "D" from the upper surface
28 of the
membrane 20 to provide a desired spacing between an overlying building
material and
the upper face 28 of the membrane 20.
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Drainage paths "P" are provided transversely across the series of filaments
34.
Preferably, this is provided by a series of depressions 40 that are formed in
the filaments
34. The depressions 40 can be created by flattening the filaments 34 at spaced-
apart
intervals along the length of the filaments 34. This is best illustrated in
FIG. 3. Thus,
each filament 34 includes an alternating array of depressions 40 and full size
filament
sections 42. The flattened sections of the filaments 34 forming the
depressions 40 project
a distance from the upper surface 28 of the membrane 20 less than that of the
diameter
"D" of the full size filament sections 42. This permits the drainage of
moisture and/or the
flow of air transversely across the filaments 34. Preferably, the depressions
40 in
adjacent filaments 34 are aligned to provide substantially straight
drainage/ventilation
paths "P" that extend transversely, or perpendicularly, across the filaments
34 and upper
surface 28 of the membrane 20. See path "P" shown in FIGs. 2 and 4.
The filaments 34 are preferably made of polymeric materials capable of being
extruded directly onto the upper surface 28 of the membrane 20 or a surface of
a
conveyer, drum, or like transfer mechanism. As examples, the filaments 34 can
be made
of nylon, polypropylene, polyester, polyolefin, polyethylene, or like
material. By way of
example, and not by way of limitation, each filament 34 can be extruded such
that it has a
diameter "D" between about 1/64 to 1/4 inch, can be flattened in intervals "I"
of about
0.5 to 6 inches, and can be spaced a distance "S" of about 1/8 to 1 inch from
adjacent
filaments. Of course, other dimensions, shapes, patterns, etc. can also be
utilized.
Preferably, the filaments 34 are thermally bonded to the membrane 20. The
polymeric material of the filaments 34 and membrane 20 engage, melt and then
solidify
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together to fuse the filaments 34 to the membrane 20 via the application of
heat and/or
pressure, particularly at the depressions 40. Thus, a separately applied
adhesive is not
required, and a strong bond can be formed. The depressed sections 40 of the
filaments 34
that are flattened are particularly strongly fused to the membrane 20 since
the pressure
exerted on the filaments 34 to create the depressions 40 results in the
formation of a
strong bond between the filaments 34 and membrane 20. Alternatively, adhesive
bonding, sonic bonding, mechanical bonding, or other techniques can be
utilized
depending on the materials of the filaments and membrane. Further, the upper
surface 28
of the membrane 20 can be textured to strengthen the bond, for example, see
the grid like
textured areas "T" randomly shown in FIGs. 2 and 4.
FIGs. 4 and 5 illustrate assemblies within which the flexible membrane 20 is
utilized to waterproof a sill surface 50 of the framework of a window opening
52 while
providing an elevated backdam 22. FIG. 4 shows the membrane 20 applied to the
sill
surface 50 of the framework prior to the installation of the window 54.
Opposite ends, 56
and 58, of the membrane 20 extend partially up the upright studs 60 and 62 of
the
framework on opposite sides of the window opening 52 and tightly conform to
the
corners of the window opening 52. As an alternative, the opposite ends, 56 and
58, of the
membrane 20 can be applied only over the windowsill itself and not onto the
upright
studs 60 and 62. In this case, other waterproofing materials would first be
installed in the
corners of the window opening, and thereafter, the membrane 20 would be
installed on
the windowsill.
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If required, the wedge 22 can be cut away and removed from the opposite end
sections, 56 and 58, of the membrane 20 that are adhered and/or secured to the
studs 60
and 62. The remainder of the membrane 20 and wedge 22 extends on the
horizontally-
disposed sill member 64 and can be bonded thereto after the release sheet 30
is removed
from the underside of the membrane 20 in a peel-and-stick manner. The wedge 22
extends under the rear portion 24 of the membrane 20 and can also be bonded or
otherwise secured to the sill member 64 such that the wedge 22 forms a backdam
along a
rearward edge of the windowsill. The forward portion 66 of the membrane 20 is
folded
over the front edge of the windowsill 64 and adhered or secured to the outside
surface of
the vertically-disposed sheathing 68.
As best illustrated in FIG. 4, each elongate filaments 34 is continuous and
extends
in a direction generally from upright stud 60 to upright stud 62 and in a
relatively
longitudinal direction on the sill member 64. The depressions 40 permit
moisture to flow
along drainage paths "P" transversely across the filaments 34 from the rear
portion 24 of
the membrane 20 toward and off the front edge of the windowsill 64. See FIG.
4.
A window 54, door, or the like may be placed on the membrane 20 and sill 64
and
installed within the opening 52. The wedge 22 forms a backdam or elevated area
along
the rearward edge of the windowsill 64. The forward edge portion 66 of the
membrane
extends over the outside surface of the sheathing 68 and will be at an
elevation lower
20 than that of the rear portion 24 of the membrane 20 disposed over the wedge
22.
Accordingly, the downward slope provides a flow path "P" across the
depressions 40 of
CA 02688139 2009-12-07
the filaments 34 and away from the rear of the sill 64 such that moisture is
directed
forwardly off the windowsill 64 underneath the window 54. See FIG. 5.
The above described flexible membrane 20 having the filament spacers 34 can
also be used at other locations within the assembly for drainage-promoting
purposes,
such as behind exterior window trim 70 (see FIG. 1). For example, after the
window 54
is installed within the opening 52, the membrane 20 can be applied over the
flanges 72 of
the window 54 adjacent the jambs and header of the window 54. See FIGs. 6 and
7. If
needed, the membrane 20 is cut to a desired size for this application. After
the membrane
20 is installed over the flanges 72, the exterior window trim 70 or like
exterior siding
material is applied over the membrane 20.
The filaments 34 provide drainage paths on the upper surface 28 of the
membrane
underneath the trim 70. This is true regardless of the orientation of the
filaments 34
on the membrane 20. For instance, drainage paths are provided between
adjacent,
spaced-apart filaments 34 as well as transversely across the filaments 34 via
the
15 depressions 40.
As stated above, the flexible membrane flashing material can be applied to
other
building openings, such as doors, skylights, and the like, as well as to
through-wall
openings for wires, cables, pipes or other conduits. The membrane can also be
applied
within and along wall corners and within and along wall-to-roof interfaces
which form
20 corner structures or the like.
Further, as illustrated in FIG. 8, the membrane 20 according to the present
invention can be applied over a deck ledger board 80 of a deck. The deck
ledger board
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80 is fastened to a wall structure 82 of a building, and the membrane 20 is
positioned to
prevent water and moisture from seeping behind the ledger board 80 to a
location
between the ledger board 80 and the adjacent wall 82. The filaments 34 on the
exterior
face 28 of the membrane 20 provide spacing elements and the flattened sections
40 of the
filaments 34 provide drainage paths "P" transversely across the filaments 34.
Thus, any
moisture penetrating within this area will be directed down and over the
ledger board 80
by the membrane 20. The membrane 20 can also be applied over the upper edges
84 of
the deck joists 86 so that any moisture penetrating between the joist 84 and
upper deck
members (not shown) can drain or be removed by evaporation from the upper
edges 84 of
the joists 86 to prevent water damage to the joists 86 and/or the overlying
deck members.
While preferred flexible membranes, assemblies, and methods have been
described in detail, various modifications, alterations, and changes may be
made without
departing from the spirit and scope of the present invention as defined in the
appended
claims.
17
