Note: Descriptions are shown in the official language in which they were submitted.
CA 02597206 2010-04-06
UNDERLAYMENT WITH IMPROVED DRAINAGE
FIELD OF THE INVENTION
The present invention relates to Underlayments employed in applications such
as
roofing, walling, siding, or flooring, and more particularly to improved
underlayments that
increase the rate of water drainage by utilizing channels in the underlayment
board.
BACKGROUND OF THE INVENTION
The use of underlayments is well known for a variety of functions, such as
thermal, noise, and air infiltration protection, moisture resistance, smooth
surface creation, and
hardiness. Typically, an underlayment is used to help reduce heating and
cooling costs and
provide a smooth, straight surface for the application of roofing, walling,
foundations, siding or
1
CA 02597206 2007-08-13
other exterior finish materials. The preferred application of the underlayment
disclosed herein is
for use as an underlayment to exterior finish materials, such as conventional
siding materials, and
other suitable uses where improved drainage is desired.
For new exterior finish materials applications, the underlayment boards
provide a
continuous air and moisture barrier for exterior finish materials such as
vinyl, aluminum, steel,
fiber cement, wood, or other suitable materials. For residing or existing
applications, the
underlayment is typically placed over the old siding to create a smooth level
surface to improve
installation and appearance.
Currently, at least one such underlayment is available from Pactiv Corporation
under the name GreenGuardO, which is a foam board made of extruded polystyrene
(XPS).
Such underlayments generally known in the prior art are flat boards with
substantially smooth
planar surfaces.
In siding applications, the siding can be applied over the underlayment by
nailing
or screwing the siding into and through the underlayment and into the studs of
the building. The
nail or screw holes that result may allow wind blown rain to penetrate the
siding. Vinyl siding
may be interlocked together, but heavy rain may drive water around the joints.
Additionally,
other avenues of water penetration include seams or cracks along windows,
doors, electrical
fixtures, water faucets, weep holes and other penetrations in the sidings.
Furthermore, power
washing of siding or drainage systems can lead to further water penetrating
the siding.
Therefore, there is a need for an tmderlayment having improved drainage.
SUMMARY OF THE INVENTION
2
CA 02597206 2010-04-06
The present invention relates generally to underlayments with improved
drainage.
Particularly, the invention relates to an underlayment board or panel having a
first surface and a
second surface, wherein the board further includes a top edge, a bottom edge,
and at least one
channel defined in the first surface. Each of the at least one channel extends
from the top edge to
the bottom. edge to form a drainage path therebetween. More particularly, the
underlayment
board can include at least one funnel defined proximate the top edge, wherein
the at least one
funnel is in fluid communication with a corresponding one of the at least one
channel.
The purpose and advantages of the present invention will be set forthin and
apparent from the description that follows, as well as will be learned from
the practice of the
invention. Additional advantages of the invention will be realized and
attained by the methods
and systems particularly pointed out in the written description and claims
hereof, as well as from
the appending drawings.
To achieve these and other advantages, and in accordance with the purpose of
the
invention, as embodied herein and broadly described, an underlayment is
provided comprising a
board having a first surface and a second surface and a top edge and a bottom
edge. The board
further includes at least one channel defined in the first surface, and each
of the at least one
channel extends from the top edge to the bottom edge to form a drainage path
thcrebetween. The
top edge and the bottom edge of the underlayment board includes a support
surface defined
between two adjacent channels against which an adjacent underlayment board can
engage.
In accordance with a further aspect of the invention, the underlayment board
can
include at least one funnel defined proximate the top edge, with the at least
one funnel in fluid
communication with a corresponding one of the at least one channel- The funnel
has a first cross
dimension exposed at the top edge and a second cross dimension at the channel,
and the first
cross dimension is greater than the second cross dimension. The funnel can
have a generally
trapezoidal, conical, or other suitable configuration. Preferably, the
underlayment includes a
3
CA 02597206 2010-04-06
plurality of funnels, where each funnel is in fluid communication with a
corresponding one of the
at least one channel.
In accordance with a further aspect of the invention, the underlayment board
can
include at least one inverted funnel defined proximate the bottom edge, with
the at least one
inverted funnel in fluid communication with a corresponding one of the at
least one channel.
3a
CA 02597206 2007-08-13
The inverted funnel has a first cross dimension exposed at the bottom edge and
a second cross
dimension at the channel, and the first cross dimension is greater than the
second cross
dimension.
In accordance with a further aspect of the invention, the at least one channel
can
be one channel or a plurality of channels. Preferably, the at least one
channel is a plurality of
channels. More preferably, the plurality of channels of the underlayment board
are generally
spaced equally apart across a substantial portion of the first surface. In a
preferred embodiment,
each channel generally defines a centerline extending axially therethrough and
the channels are
spaced apart with the centerlines of adjacent channels being about one inch
apart or less.
In accordance with a further aspect of the invention, the underlayment board
has a
thickness between the first surface and the second surface, and preferably
each channel has a
depth between about 5% and 75% of the thickness of the board and each funnel
has a depth equal
to or greater than the depth of the channel. More preferably, the depth of
each channel can be
between about 10% and 50% of the thickness of the board.
In accordance with a further aspect of the invention, the board has opposing
side
edges. Preferably, at least one of the opposing side edges includes an
engagement surface
against which a corresponding side edge of an adjacent underlayanent board can
be engaged.
The engagement surface can be shaped to interlock with a corresponding side
edge of an
adjacent underiayment board.
In accordance with a further aspect of the invention, the board is a single-
piece
construction, such as a polymer material. The polymer material can be selected
from the group
consisting of polyisocyanurate foam, polyurethane foam, expanded polystyrene
(EPS), extruded
polystyrene (XPS), and the like. Preferably, the polymer material is extruded
polystyrene.
4
CA 02597206 2007-08-13
Alternatively, the board can be a laminate including a first layer defining
the first
surface and a second layer defining the second surface. The first layer can be
made of a material
that is the same as or different than the second layer as desired.
In accordance with a further aspect of the invention, the second surface can
include channels. Alternatively, the second surface is generally planar and
free of channels. A
film layer, such as foil, can be provided on the second surface. The first or
second surface of the
board can include one or more indicia, such as, but not limited to, a logo,
installation
instructions, or assistance graphics or grids.
In accordance with another aspect of the invention, the top edge of the board
can
be angled, slanted, shiplapped, or otherwise shaped to direct drainage toward
the channels of the
first surface. The bottom edge also can be angled, slanted, shiplapped, or
otherwise shaped
accordingly to mate with the top edge.
In accordance with another aspect of the invention, a building assembly
comprises
a structural substrate having a substantially vertical face, an underlayment,
and an exterior finish
material. The underlayment includes a board having a first surface and a
second surface and a
top edge and a bottom edge. The underlayment board further has at least one
channel defined in
the first surface. Each of the at least one channel extends from the top edge
to the bottom edge
of the board to form a drainage path therebetween_ The board is disposed with
the second
surface facing the face of the structural substrate. The exterior finish
material is secured adjacent
the first surface of the underlayment board with the underlayment board
sandwiched between the
structural substrate and the exterior finish material. A second underlayment
board of similar
construction can be provided, wherein the second underlayment board has an
edge disposed
CA 02597206 2007-08-13
against at least one edge of the first underlaynent board. Each underlayment
board can include
one or more of the features described herein.
In accordance with another aspect of the invention, a method is provided for
finishing a structural substrate having a generally vertical face. The method
includes providing
an underlayment including a board having a first surface and a second surface,
the board further
including a top edge and a bottom edge. The board further has at least one
channel defined in the
first surface, and each of the at least one channel extends from the top edge
to the bottom edge to
form a drainage path therebetween. The method further includes disposing the
underlayment
board with the second surface facing the face of the structural substrate, and
the at least one
channel aligned generally vertically. The method further includes securing an
exterior finish
material adjacent the first surface of the underlayment board with the
underlayment board
sandwiched between the structural substrate and the exterior finish material.
The structural
substrate can be the frame of a building structure, an existing exterior
finish material, a
sheathing, or other conventional structure as is known.
Thus, in accordance with the present invention, an underlayment is provided
with
an increased rate of drainage. The improvements are achieved while maintaining
an R value, as
desired, as good as underlayments which do not include drainage channels. Such
increased
drainage can reduce water penetration to the interior of the building, as well
as minimize or
eliminate mold under the exterior finish material by preventing pooling of
water and facilitating
air circulation,
It is to be understood that both the foregoing general description and the
following detailed description are exemplary and are intended to provide
further explanation of
the invention claimed.
6
CA 02597206 2010-04-06
The accompanying drawings, which are incorporated in and constitute part of
this
specification, are included to illustrate and provide further understanding of
the method and
system of the invention. Together with the description, the drawings serve to
explain the
principles of the invention.
According to an aspect of the present invention there is provided an
underlayment
for exterior finish material, the underlayment comprising:
a board having a first surface and a second surface, the board further
including a top edge
and a bottom edge;
at least one channel defined in the first surface, each of the at least one
channel extending
from proximate the top edge to proximate the bottom edge to form a drainage
path
therebetween; and
at least one funnel defined proximate the top edge, the at least one funnel in
fluid
communication with a corresponding one of the at least one channel.
According to another aspect of the present invention there is provided a
building
assembly comprising:
a structural substrate having a generally vertical face;
an underlayment including a board having a first surface and a second surface,
the board
further including a top edge and a bottom edge, the board having at least one
channel
defined in the first surface, each of the at least one channel extending from
proximate the
top edge to proximate the bottom edge to form a drainage path therebetween,
the board
disposed with the second surface facing the face of the structural substrate,
the board
further including at least one funnel defined proximate the top edge, the at
least one funnel
in fluid communication with a corresponding one of the at least one channel;
and
7
CA 02597206 2010-04-06
an exterior finish material secured adjacent the first surface of the
underlayment board
with the underlayment board sandwiched between the structural substrate and
the exterior
finish material.
According to a further aspect of the present invention there is provided a
method of
finishing an exterior of a structural substrate having a generally vertical
face comprising:
providing an underlayment including a board having a first surface and a
second surface,
the board further including a top edge and a bottom edge, the board having at
least one
channel defined in the first surface, each of the at least one channel
extending from
proximate the top edge to proximate the bottom edge to form a drainage path
therebetween,
the board further including at least one funnel defined proximate the top
edge, the at least
one funnel in fluid communication with a corresponding one of the at least one
channel,
disposing the underlayment board with the second surface facing the face of
the structural
substrate, the at least one channel being aligned generally vertically; and
securing an exterior finish material adjacent the first surface of the
underlayment board
with the underlayment board sandwiched between the structural substrate and
the exterior
finish material.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further appreciation of the above and other advantages, reference is
made to
the following detailed description and to the drawings, in which:
Figure 1 is a front perspective view of the prior art underlayment;
Figures 2a and 2b are front perspective views of embodiments of an
underlayment having
channels in accordance with the invention;
Figures 3a and 3b are detailed front perspective views of the top edge of
embodiments of an
7a
CA 02597206 2010-04-06
underlayment having funnels in fluid communication with the channels in
accordance with
another aspect of the invention;
Figure 4 is a partial front view of two adjacent underlayments of figure 3a in
alignment;
Figure 5 is a partial front view of two adjacent underlayments of Figure 3a
that are not aligned;
Figure 6 is a front view of another embodiment of an underlayment having a
plurality of
channels and slanted top and bottom edges;
Figure 7 is a side view of the underlayment of Figure 6; and
Figure 8 is a side perspective view of one embodiment of a building assembly
having an
underlayment with channels in accordance with the invention.
7b
CA 02597206 2010-04-06
DETAILED DESCRTPTION OF THE PREFERRED EMBODIMENTS
While the present invention will be described with reference to a few specific
embodiments, the description is illustrative of the invention and is not to be
construed as limiting
the invention. Various modifications to the present invention can be made to
the preferred
embodiments by those skilled in the art without departing from the true spirit
and scope of the
invention as defined by the appended claims. It will be noted that like
components are
designated by like reference numerals throughout the various figures.
Referring now to Figure 1, an underlayment 100 of the prior art is depicted.
The
underlayment is a rectangular board or panel which includes a first surface
110, a second surface
120 (not shown), a top edge, a bottom edge, and opposing side edges labeled
130, 140, 150, and
160, respectively. Generally, the first and second surfaces are substantially
smooth. The board
can be made of any known and suitable material.
In accordance with the invention, an underlayment is provided comprising a
board
having a first surface and a second surface, the board further including a top
edge and a bottom
edge. The board further includes at least one channel defined in the first
surface, and each of the
at least one channel extends from the top edge to the bottom edge to form a
drainage path
therebetween. The top edge and the bottom edge each includes a support surface
defined
between two adjacent channels against which an adjacent underlayment board can
engage.
For purpose of illustration, and not limitation, reference is made to the
embodiment of Figure 2a. Figure 2a shows an underlayment 200 having a first
surface 210, a
second surface (not shown), a top edge 230, and a bottom edge 240. The
plurality of
channels 215 are defined in the first surface, wherein each channel extends
from the top edge to
the bottom edge to form a drainage path therebetween. A support surface 225 is
defined between
8
CA 02597206 2007-08-13
two adjacent channels. As shown in Figure 2b, in a preferred embodiment, the
second surface
can include channels 235, for example when escaping interior moisture of a
building is a
concern. Alternatively, the second surface is generally planar and free of
channels.
The channels can have any suitable configuration and alignment which results
in
increased drainage. For example, the channels 215 can have a polygonal or
rectilinear cross
section as shown in Figure 2a, or in a preferred embodiment, the channels 315
(as shown in
Figure 3a) can have at least a partially curved or circular cross section to
eliminate any sharp
edges that may be difficult to form and that could result in resistance to
drainage. Additionally,
each groove or channel can vary in cross sections along its length, or
adjacent grooves can be
provided with different cross sections. Preferably, the plurality of channels
215 are aligned
vertically as shown in Figure 2a. The channels however, can be aligned at an
angle relative to
the top edge, such as diagonal. If desired, the channels can interconnect
along their lengths as
shown 316 in Figure 3b, or the channels can be parallel and not interconnect,
as shown in Figure
2a. If it is desired to control or regulate the drainage rate, the channels
can be varied in
dimension or shape or otherwise formed to define a more tortuous drainage path
to avoid water
pooling or back flow.
The at least one channel can be either one channel or a plurality of channels
such
that the number of channels and the spacing between channels can be varied to
provide desired
results- For example, in a preferred embodiment, the at least one channel is a
plurality of
channels. More preferably, the channels can be equally spaced apart. Each
channel defines a
centerline extending axially therethrough, and in a preferred embodiment, the
channels are
equally spaced apart with the centerlines of adjacent channels being about one
inch apart or less.
In one preferred embodiment, the spacing is about 1 "_ In this manner, a
support surface 225 is
9
CA 02597206 2007-08-13
defined between two adjacent channels. This support surface can be engaged by
and support an
adjacent panel of similar construction if desired. Additionally, by spacing
the channels
appropriately, flexibility can be introduced into the board, such that the
board can be rolled prior
to installation if desired.
In one preferred embodiment, the underlayment board is a single-piece
construction. The underlayment 200 can be constructed from a variety of
suitable materials or a
combination of suitable materials. For example, the underlayment can be
constructed of wood,
plywood, composite particle board, oriented strand board, fiberglass-faced
gypsum board, foam,
expanded polystyrene (EPS - beadboard), extruded polystyrene (XPS), and any
other suitable
material. The preferred material is a polymer material, selected from the
group consisting of
polyisocyanurate foam, polyurethane foam, expanded polystyrene, and extruded
polystyrene.
Preferably, the polymer material is extruded polystyrene.
As depicted herein, the underlayment boards are rectangular boards which can
be
of any suitable dimension. For example, but without limitation, the dimensions
of a single board
can be between I to 6 foot by 2 to 10 foot. More preferably, the dimensions of
a single board
can be about 4' by 8'. Alternatively, the underlayment boards can be
interconnected in a fanfold
configuration. The fanfold configuration can be created by creasing and
folding, or cutting and
folding, the materials from which the board is made. In this manner, but
without limitation, the
dimensions of the interconnected fanfold boards can be between 1-6' by 10-80'
or more. More
preferably, the dimensions of the fanfold boards is about 4' by 48'. If the
board is sufficiently
flexible, a roll configuration can be provided for the board. The boards can
be of any suitable
thickness. Preferably, the underlayment boards are between 1/8" and 3/8"
thick.
CA 02597206 2010-04-06
The first surface 210 and/or the second surface can be non-faced or optionally
can be covered with a coating or film- The coating or film can be applied with
an adhesive or
other conventional techniques. The coating can be a foil, such as a metalized
polyolefin or the
like. Alternatively, the coating can be a film of a variety of suitable
materials or a combination
of suitable materials including a polyester, nylon, fiberglass, polymer or the
like. In a preferred
embodiment, the first and/or second surface include a high impact polystyrene
coating. The
optional films and coatings can provide a vapor and radiant barrier, chemical
resistance, and/or
durability without substantially affecting the rate of drainage through the
channels.
The use of channels, and particularly, the preferred vertical channels shown
in Figure 2a
as 215, results in increased drainage as compared to a conventional
underlayment board which
does not include channels. For example, if a section of exterior finish
material presses up against
a conventional underlayment, it may cause water to be trapped and pooled
between the surfaces.
The pooling can result in water seeping toward the house through screw or nail
holes in the
underlayrent boards or the seams of adjacent underlayment boards. The channels
therefore
prevent or reduce such surface contact, as well as facilitate drainage as
desired. Therefore,
increased drainage can reduce water penetration to the interior of the
building, as well as
minimize or eliminate mold under the exterior finish material by preventing
pooling of water and
facilitating air circulation.
Additionally, the use of vertical channels can provide vertical strength
improvement for the underlayment board. Any of a variety of dimensions,
spacing, and shapes
can be used to define the channels and provide suitable drainage and strength.
Additionally, the
dimension or depth of the channel will depend on the thickness of the board.
The underlayment
board has a thickness between the first surface and the second surface and
preferably each
II
CA 02597206 2007-08-13
channel has a depth between about 5% and 75% of the thickness of the board.
More preferably,
the depth of each channel can be between about 10% and 50% of the thickness of
the board.
Therefore, the dimensions of the grooves ultimately will depend upon the board
thickness and
the desired drainage rate.
In a preferred embodiment, the underlayment board 200 has opposing side edges
250 and 260 that include engagement surfaces against which a corresponding
side edge of an
adjacent underlayment board can be engaged. Further, the opposing side edges
can be shaped in
any suitable configuration, such as shiplap or the like, to interlock with a
corresponding side
edge of an adjacent underlayment board. Additionally, opposing side edges can
also include flat,
recessed surfaces designed to accommodate taping of the seams, such as shown
in Figure 3b,
which allows the underlayment installation to meet the AC71 criteria for a
weather resistive
barrier.
Referring now to Figures 3a and 3b, and in accordance with another aspect of
the
invention, misalignment features can be provided proximate to the top edge,
the bottom edge, or
both. Generally, the misalignment features allow for two underlayment boards
of similar or
identical construction to be positioned vertically adjacent to each other and
allow for drainage
there across even if the channels of the adjacent boards are not axially
aligned. For example, the
misalignment feature embodied herein is depicted in the form of a funnel
configuration at at least
one end of a channel to allow fluid communication with a channel of an
adjacent board. Hence,
the misalignment features can have a variety of forms, configurations, or
shapes suitable to
facilitate drainage and account for possible misalignment of the underlayment
boards during
installation.
12
CA 02597206 2010-04-06
As embodied herein for illustration and not limitation, and as shown in Figure
3a,
funnel 370 is defined proximate the top edge 330 of the underlayment 300.
Additionally, the
underlayment 300 can include an inverted funnel defined proximate the bottom
edge 340
(not shown). Each funnel is in fluid communication with a corresponding
channel 315. The
funnel 370 embodied herein has a first cross dimension exposed at the top edge
and a second
cross dimension at the channel. Preferably the first cross dimension is
greater than the second
cross dimension. Likewise, the funnel at the bottom edge, as embodied herein,
has a first
cross dimension exposed at the bottom edge and a second cross dimension at the
channel. See,
for example, funnel 471 in Figure 4. Preferably, the first cross dimension is
greater than the
second cross dimension.
It is further preferred that the funnels, as shown in Figure 3a, have a sloped
surface directed toward the channel, such as a trapezoidal or conical shape or
the like.
Preferably, the surface along the top and/or bottom edges between the funnels
are minimized
without affecting the forming of the funnel or the strength of the board. This
allows for
increased misalignment between the channels and reduces splash when the
draining water exits
the bottom of the channel and funnel of one board and enters the top funnel of
an adjacent board.
Preferably, the flannels have a depth equal to or greater than the depth of
the
channel. Hence, for example, the thickness of the backwall of the funnel can
be less than 1/2",
and more preferably less than 1/4". The funnels can be formed in the same
manner and
simultaneous with forming the channels. In a preferred embodiment, the
underlayment board
can include a plurality of funnels, and more preferably, a funnel is defined
proximate the top
edge of each channel and an inverted funnel is defined proximate the bottom
edge of each
13
CA 02597206 2007-08-13
channel. This preferred embodiment eliminates the single orientation of the
board because of its
symmetry.
For purpose of illustration, Figure 4 shows two adjacent underlayments 300 and
400 in axial alignment in accordance with the invention. The arrow labeled 480
shows the
drainage path through the drainage channel 415 and funnel 471 and into
adjacent funnel 370 and
channel 315.
Figure 5 shows two adjacent underlayments 300 and 400 which are misaligned.
The arrows labeled 480 show the drainage paths through the drainage channels
415 and the
funnels 471 and into adjacent funnels 370 and channels 315. As can be seen in
figure 5, it is
preferable to have the edge cross dimension of the funnel greater than the
spacing between the
funnels such that drainage occurs from one underlayment board to the next even
if the channels
are out of phase or misaligned as shown.
In another embodiment, the underlayment board having a first surface and a
second surface and a top edge and a bottom edge includes at least one channel
defined as a
microchannel or microgroove with each of the at least one channel extending
from the top edge
to the bottom edge to form a drainage path therebetween. Each microgroove has
a reduced
cross-sectional dimension as compared to the grooves previously described; a
greater number of
grooves are provided to facilitate similar drainage characteristics. Each
microgroove defines a
centerline extending axially therethrough, and in a preferred embodiment, the
microgrooves are
equally spaced apart with the centerlines of adjacent channels being less than
about 1/4" apart.
The underlayment board has a thickness between the first surface and the
second surface and
preferably each microgroove has a depth between about I% and 25% of the
thickness of the
board. Further, misalignment features can be provided proximate to the top
edge, the bottom
14
CA 02597206 2010-04-06
edge, or both- For example, and in a preferred embodiment, the top and/or
bottom edges are
angled or slanted toward the first surface to direct drainage toward the
grooves. This accounts
for misalignment of the channels and prevents water from seeping toward the
interior of the
building.
For the purpose of illustration and not limitation, Figure 6 shows an
underlayment
600 which includes microgrooves 615 and further includes a slanted top edge
690 and a bottom
edge (not shown). Figure 7 shows two adjacent underlayments 600 and 700
similar to that
of Figure 6, with a slanted top edge 690 and a slanted bottom edge 790. In a
preferred
embodiment the top edge 690 and bottom edge 790 are slanted .lap joints. When
water drains to
the bottom of panel 700, the slanted lap joint directs the drainage toward the
first surface and
thus prevents water from flowing toward the interior of the building. In this
manner, the water
will drain toward the first surface or the exterior of the top edge of
adjacent underlayment board
W.
Any of a variety of techniques can be used for fabrication of the
underlayments
with grooves defined therein. For example, the underlayment board can be
formed of a single
piece construction by extrusion and/or subsequent process steps. That is, and
by using a polymer
material, the underlayment board can be extruded with grooves formed therein,
using an in-line
cylinder, die or the like. Alternatively, the single piece polymer board can
be extruded with
substantially smooth surfaces, and then the grooves can be defined by
thennofonning,
embossing, coining, notching, calendering or other known techniques. In a
preferred
embodiment, the process includes extruding a foam board, cooling the board,
and then
thermoforming the channels into the front surface of the foam board using a
cylinder or plate
pressed against the outer surface of the material to form the channels (e.g-,
calendering or
CA 02597206 2007-08-13
coining process). Alternatively, the underlayment board of polymer or other
suitable material,
can be processed to form the grooves by removing material by using a
mechanical cutter or
groover (CNC) machine and other suitable known techniques. Further, in
accordance with
another aspect of the invention, the board can be a laminate having a first
layer defining the first
surface and a second layer defining the second surface. The first and second
layers can be the
same material, or in a preferred embodiment, are different materials. Each
material can be
selected to provide a particular characteristic, such as strength, vapor
barrier, or the like. The
grooves therefore can be formed using a technique previously described, or by
laminating a
material to define the desired grooves (e.g. a cloth, film, or slats) to the
foam board or the film
covering the foam board.
Further, in accordance with another aspect of the invention, when
thermoforming
the channels onto both surfaces of the foam board, the flatness of the board
can be more easily
maintained. In a preferred embodiment, providing similar channels on the first
and second
surfaces, wherein the location of the channels of the first surface are offset
from the location of
channels of the second surface, helps improve the flexural strength of the
product versus
providing the channels at the same location on the first and second surfaces.
Having channels on
the second surface is advantageous because when the board is installed in
direct contact with a
flat wall sheathing member, it allows water to drain down the second surface
of the drainage
underlays sent board between it and the wall sheathing in the event water
finds its way through
the seams of the board or water leaks behind the drainage board at a window or
door interface.
Further, in accordance with another aspect of the invention, and as recognized
from the previous description, a method is provided for finishing an exterior
of a structural
substrate having a generally vertical face. The method includes providing an
underlayment
16
CA 02597206 2007-08-13
board having a first surface and a second surface, the board further including
a top edge and a
bottom edge, the board having at least one channel defined in the first
surface, each of the at least
one channel extending from the top edge to the bottom edge to form a drainage
path
therebetween, as previously described. The method further includes disposing
the underlayment
board with the second surface facing the face of the structural substrate, and
securing an exterior
finish material adjacent the first surface of the underlayment board with the
underlayment board
sandwiched between the structural substrate and the exterior finish material.
Preferably, the at
least one channel is aligned generally .vertically. The structural substrate
can be the frame of a
building structure, a sheathing, a house wrap or a building paper, an existing
exterior finish.
material, or the 1 ike. Two or more similar underlayment boards can be
provided and positioned
in adjacent locations as previously described to facilitate drainage as
desired. Any known
methods and techniques can be used to locate and secure the underlayment
between the structural
substrate and the exterior finish material, provided the first surface of the
underlayment and
grooves defined therein are facing the exterior finish material.
In remodeling applications, the underlayment can be applied over the existing
exterior finish material. Alternatively, the existing exterior finish material
and existing
underlayment may be removed such that the new underlayment can be applied over
the house
wrap, building paper, or sheathing that remains or is applied on the frame of
the building
structure. In new constructions, the underlayment can be applied over the
house wrap, building
paper, or sheathing.
Alternatively, for new constructions, and in accordance with another aspect of
the
invention, the sheathing can include channels, misalignment features, and/or
any of the other
features described herein such that the exterior finish material can be
applied directly over the
17
CA 02597206 2007-08-13
sheathing without the need for a house wrap, building paper, or underlayment.
The sheathing
can be constructed from the same materials as the underlayment 200 listed
above. Preferably,
the sheathing can be formed using a different blowing agent such that it has a
high R value as is
known in the art. Preferably, the sheathing is 1/2" to 1" thick and more
preferably 7/16" to 1"
thick.
Further, in accordance with another aspect of the invention, and in this
manner, a
building assembly can be provided which includes a structural substrate having
a generally
vertical face, an underlayment board having a first surface and a second
surface, the board
further including a top edge and a bottom edge, the board having at least one
channel defined in
the first surface, each of the at least one channel extending from the top
edge to the bottom edge
to form a drainage path therebetween, and an exterior finish material secured
adjacent the first
surface of the underlayment board with the underlayment board sandwiched
between the
structural substrate and the exterior finish material. The building assembly
can further include a
second underlayment board of similar construction having an edge disposed
against an edge of
the first underlayment board as previously described. Each underlayment board
of the building
assembly includes one or more of the features previously described herein. In
one embodiment,
the channels of the adjacent boards are in alignment. In another embodiment,
the adjacent
boards can be out of alignment, yet still facilitate drainage along the first
surface-
As embodied herein for illustration and not limitation, and as shown in Figure
8, a
building assembly is depicted. The building assembly includes a structural
substrate 891 having
a generally vertical face, an underlayment board 800, and an exterior finish
material 892. The
underlayment board 800 is sandwiched between the structural substrate 891 and
the exterior
finish material 892 such that the first surface 810 of the underlayment board
800 including a
18
CA 02597206 2007-08-13
plurality of channels 815 faces the exterior finish material 892. The
structural substrate maybe
the frame of a building structure, a sheathing, a house wrap or a building
paper, an existing
exterior finish material, or the like,.
The underlayments can also be provided with at least one indicia such as, but
not
limited to, a logo, installation instructions, or assistance graphics or grids
printed on the first
and/or second surface of the board. Most professional installers try to use as
much of the
underlayment material as possible, including scraps that were cut in covering
another portion of
the building, so the scraps can fit in such a way that the logo is upsidedown,
but this is not a
problem as the channels are vertical and include funnels at both the top and
bottom of the
channels. Additionally, the underlaytnent material (e.g., scrap material) can
be installed at an
angle.
It will be seen from the foregoing that the present invention provides an
underlayment board with improved drainage. Although a number of specific
embodiments of the
invention above have been illustrated, various modifications thereof will be
apparent to those
skilled in the art within the spirit of the invention. Accordingly, it will be
evident that the scope
of the invention is to be limited only as set forth in the appended claims.
19
