Note: Descriptions are shown in the official language in which they were submitted.
CA 02490286 2004-12-15
BUILDING PANEL
FIELD OF THE INVENTION
The present invention relates to building panels, and more particularly
to building panels including a conduit system for transmission of water vapor.
BACKGROUND OF THE INVENTION
In the context of exterior building panels, the presence of moisture can
lead to undesirable results. Moisture that becomes trapped within and between
panels can generate rot in the substrate to which the panel is affixed, it can
bleed
through the panel finishing coat and discolour it, and it can even cause the
panel to
detach from the substrate.
Prior attempts to address this problem include Canadian Patent
1,220,041 to Larsson, which teaches a panel having drainage channels for use
with
subterranean wall surfaces. The channels communicate directly with the
subterranean wall surface, as the channels are intended to direct water
accumulation on the concrete surface away from that concrete surface. United
States Patent 6,318,041 to Stanley discloses a panel system that also employs
drainage channels or conduits.
While various attempts have been made to address the problem of
moisture in a variety of building panel contexts, a need has been felt for an
improved
means of addressing the problem in the specific context of Exterior Insulated
Finish
System (EIFS) technology. The EIFS system, developed in Europe in the 1950s,
uses multi-layered exterior wall systems for both commercial and residential
buildings, and it typically consists of an interior insulation board secured
to the
~
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exterior wail surface, a reinforced base coat applied to the insulation board,
and a
finish coat that is both visually attractive and resistant to environmental
impact. The
superior energy efficiency and design flexibility of the EIFS system have
resulted in
growing popularity, but the presence of moisture remains a vexing problem.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided an
insulated building panel for affixing to exterior building surfaces in rows of
the panels
side by side and top to bottom to form an array of the panels, the building
panel
comprising:
a panel body formed of an insulating foam material, the panel body
having:
opposed inside and outside surfaces generally parallel to each other;
opposed top and bottom horizontal sides arranged for butting
engagement with other similar panel bodies;
opposed left and right vertical sides arranged for butting engagement
with other similar panel bodies;
the panel body having therein a plurality of conduits for transmission of
water vapour through the array of panel bodies including at least one
generally
horizontal conduit spaced from the front and back surfaces and a series of
transversely spaced generally vertical conduits spaced from the front and back
surfaces;
the number of vertical conduits and the spacing between the vertical
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conduits being arranged such that water vapor migrating from the inside
surface
toward the outside surface is collected in the conduits prior to reaching the
outside
surface;
wherein the at least one horizontal conduit is defined by a groove
located at one of the horizontal sides such that the conduit is defined by an
open
area defined between an adjacent surface of an adjacent panel on one side and
a
wall of the groove in the panel on the other side with the dimensions of the
area so
formed being sufficient to allow the passage of water vapor therethrough.
Preferably the at least one horizontal conduit is defined by a groove
located at one of the horizontal sides and which has an open mouth at the side
and
converges inwardly toward an apex as it extends into the panel body. This is
preferably the top side but may be the bottom side.
Preferably the groove has a width at its mouth in the horizontal side of
the panel in a direction at right angles to the inner and outer surfaces at
least equal
to a width in the same direction of the vertical conduits.
Preferably the groove has a width at its mouth in the horizontal side of
the panel in a direction at right angles to the inner and outer surfaces
greater a width
in the same direction of the vertical conduits.
Preferably that side of the groove which is adjacent the inner surface is
substantially coincident with an adjacent side of the vertical conduits and
that side
which is adjacent the outer surface extends closer toward the outer surface
than
does the vertical conduit.
Preferably one half of the distance between one of the vertical conduits
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and the next is less than the distance between said one of the vertical
conduits and
the outer surface such that water vapor tends to migrate to the conduits in
preference to the outer surface.
Preferably the groove and the vertical conduits are closer to the inner
surface than the outer surface.
Preferably the groove is V-shaped in cross section.
Preferably the vertical conduits are rectangular in cross section.
Preferably the vertical conduits are formed by molding such that they
are free from a wire cut connection to an external surface of the panel body.
Preferably each of the vertical sides includes a groove.
Preferably at least one of the vertical and horizontal sides includes a
stepped joint.
Preferably the stepped joint also includes a groove.
According to a second aspect of the invention there is provided an
insulated cladding system affixed to an exterior building surface comprising:
a plurality of insulated building panels affixed in rows of the panels side
by side and top to bottom to form an array of the panels defining an exterior
surface;
one or more exterior coating layers applied over the exterior surfaces
of the panels to form an exterior finish of the building;
each building panel comprising a panel body formed of an insulating
foam material, the panel body having:
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opposed inside and outside surfaces generally parallel to each other;
opposed top and bottom horizontal sides arranged for butting
engagement with other similar panel bodies;
opposed left and right vertical sides arranged for butting engagement
with other similar panel bodies;
the panel body having therein a plurality of conduits for transmission of
water vapour through the array of panel bodies including at least one
generally
horizontal conduit spaced from the front and back surfaces and a series of
transversely spaced generally vertical conduits spaced from the front and back
surfaces;
the number of vertical conduits and the spacing between the vertical
conduits being arranged such that water vapor migrating from the inside
surface
toward the outside surface is collected in the conduits prior to reaching the
outside
surface;
wherein the at least one horizontal conduit is defined by a groove
located at one of the horizontal sides such that the conduit is defined by an
open
area defined between an adjacent surface of an adjacent panel on one side and
a
wall of the groove in the panel on the other side with the dimensions of the
area so
formed being sufficient to allow the passage of water vapor therethrough.
In exemplary embodiments of the present invention, the building panel
is for thermal insulation and for collection and drainage of moisture from
water
vapour, and the building panel is made of expanded polystyrene or
polyisocyanurate. The generally horizontal groove is preferably V-shaped in
cross
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section and configured to facilitate lateral movement of moisture from water
vapour
to the at least one generally vertical channel for downward flow of the
moisture
through the at least one generally vertical channel, and the at least one
generally
vertical channel is preferably rectangular in cross section. The building
panel is
preferably of unitary, shape-moulded construction.
By providing a building panel that can both insulate and efficiently
direct moisture from water vapour away from the panels and underlying
substrate,
while serving the need for an even surface for application of the base and
finish
coats, the present invention is intended to address a pressing need in the
industry.
A detailed description of an exemplary embodiment of the present
invention is given in the following. It is to be understood, however, that the
invention
is not to be construed as limited to this embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
Figure 1 is a side cross-section along line I-I in Figure 2 of an in situ
assembly of building panels according to the present invention.
Figure 2 is a front elevation of the assembly of Figure 1.
Figure 3 is a plan view of a building panel according to the present
invention.
Figure 4 is a top plan view on an enlarged scale of one part of one of
the panels of the previous figures.
Figure 5 is a cross sectional view transversely through two of the
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panels stacked one on top of the next.
Figure 6 is a cross sectional view similar to that of Figure 4 showing a
modified arrangement with a ship-lap connection between the panels.
DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT
Referring now in detail to the accompanying drawings, and particularly
to Figures 1 and 2, there is illustrated an assembly of building panels
according to
the present invention, each panel being referred to generally by the numeral
10.
The building panel 10 comprises opposed front and back sides 14, 16 generally
parallel to each other and opposed top and bottom edges 18, 20 generally
parallel to
each other. Conduits for transportation of water vapor are provided in the
panel
including a generally horizontal V-shaped groove 22 in the top edge 18 spaced
from
the front and back sides 14, 16, and generally vertical channels 24 extending
downwardly from the groove 22 though the building panel 10 to the bottom edge
20
at a point on the bottom edge 20 spaced from the front and back sides 14, 16.
Thus
the V-shaped groove is located at the surface and has an open mouth at the
surface
and converges inwardly and downwardly into the panel body to an apex. While
Figure 2 shows the channels 24 only in the centrally positioned building panel
10,
the channels 24 are also in each of the adjacent building panels 10. The
building
panel 10 is of a unitary, shape-moulded construction, an advantage over
traditional
wire-cut construction since the vertical channels are free from the necessary
wire cut
entry slot from an adjacent surtace of the panel.
As can be seen in Figure 1, interior surface of the building panel 10 is
includes an air barrier membrane 26 which is applied to an exterior surface 12
of a
CA 02490286 2004-12-15
building 13 as an air/vapour barrier by an adhesive 28. In the illustrated
embodiment the adhesive 28 is applied as a layer prior to positioning of the
building
panel 10.
Thus the exterior building surface 12 is arranged to be suitable for
application of the building panels 10. Suitable substrates include but are not
limited
to exterior grade drywall, cement board, plywood sheathing, Dens-Glass
sheathing,
precast concrete, concrete block, or poured-in-place concrete. The air/vapour
barrier
membrane 26 is applied to the exterior building surface 12. An adhesive 28 is
then
applied on top of the membrane 26.
The building panels 10 are then applied over this adhesive layer 28
and secured in place thereby. For a building of four stories or greater it is
advisable
to use mechanical fasteners as well to secure the panels to the exterior
building
surface 12.
The building panels 10 are preferably arranged in the offset pattern
shown in Figure 2, a pattern well known in the art. The joints between the
building
panels 10 should be sealed with a suitable material (not shown) known to those
skilled in the art to further enhance the insulating properties of the
building panels
10.
Various methods of providing base and finishing coats (not shown) are
then possible, according to the general knowledge of those skilled in the art
of EIFS
use.
With the building panels 10 now in place on the exterior building
surface 12 and finished in a suitable manner, the groove 22 is now configured
to
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_g _
facilitate lateral movement of water vapour to the channels 24 for downward
flow of
the water vapor through the channels 24. Water vapor can flow horizontally
through
a groove 22 and into adjacent grooves 22 as necessary, while the channels 24
then
provide vertical conduits for the water vapor flowing through the grooves 22.
As is well known in the EIFS system, the exterior cladding formed by
the rows and columns of panels of insulating foam are covered on the exterior
surface by a first layer 30 which is a flexible mortar layer commonly having
embedded therein a reinforcing fiber layer together with an exterior coating
31 of a
flexible coloured material. These coatings are well known to one skilled in
the art
and commonly used. Different types of coating can be used.
Each of the blocks or panels forming the system therefore comprises
the block as defined above which has an interior surface of the foamed
insulation
material indicated at 32 and an exterior surface 33. These surtaces are
parallel and
defined on the exterior of the insulation material which forms the block and
is located
therebetween. The block further includes horizontal sides 34 and 35 at the top
and
bottom respectively and vertical sides 35 and 36. These sides are at right
angles to
the front and rear surfaces so as to form a rectangular block or panel of the
required
thickness with each of the panels being of the same height and the same width.
The
panels are then arranged in rows with the top and bottom surfaces abutting and
the
sides surfaces also abutting.
The exterior coating surfaces 30 and 31 are applied directly onto the
outside surface and there are no external sheeting elements.
The conduit system defined in the present invention is arranged to
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communicate moisture in the form of water vapour through the system to an
exterior
location. The system is not intended to nor required to communicate any form
of
flowing water since the amount of moisture which can penetrate is very low.
The
required escape of moisture is therefore also very low but, if prevented from
escape,
can collect over time which may be many weeks or many months leading to that
moisture penetrating through the permeable foam to the exterior surfaces 30
and 31
causing damage thereto.
Differential pressures across the foam panels can cause water vapour
to transfer or permeate through the structure. The water vapour tends to
migrate to
paths of least resistance so that, provided the conduit system provides
sufficient
cross sectional area of the conduits, the water vapour will tend to migrate to
these
conduits and pass therethrough in gaseous form in the air contained within the
conduits to any exterior vent.
As best shown in Figures 4 and 5, the vertical conduits 16 are
arranged in a series spaced along the length of the panel. Thus as shown in
Figure
5, each of the conduits 16 is rectangular in cross section and has a width W
with a
spacing between each conduit and the next of S. The conduits are arranged so
that
the distance D1 from the inner surface 32 is less than the distance D2 from
the outer
surface 33. Also the spacing S between each conduit and the next is arranged
so
that moisture tending to migrate from the inside surface 32 toward the outside
surface has a shorter distance to travel to the conduit 16 than to the
exterior surface
33 along the distance D2. Thus moisture at a point P in the panel tends to
migrate
along the distance S/2 to the conduit 16 than over the distance D2 to the
exterior
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surface. Thus any moisture contained between the vapour barrier 26 and the
panel
will tend to migrate to the conduits and travel along the conduits as water
vapour to
an exterior vent.
In order to provide horizontal transfer of the water vapour, there are
provided the grooves 22. These are preferably provided in the top surface 34
of the
panel 10 but could additionally be provided in the bottom surface 35 of the
panel
10A or could be provided only in the bottom surface 35 of the panel 10A.
However
these grooves are provided at the surface so that the groove has an open mouth
22A at which is located a portion 35A of the bottom surface 35 closing the
open
mouth 22A. Further the conduit is defined by portions 22B and 22C of the
groove
converging to an apex 22D. Thus the groove converges inwardly towards the apex
as the groove extends into the body of the panel.
This arrangement allows the grooves to be formed as common action
in molding the vertical conduits 16. Thus a mold which is generally
rectangular in
the form of the shape of the panel also includes insert elements which define
the
groove 22 and the channels or conduits 16. Thus a bar which is triangular in
shape
defines the groove 22 and the bar houses a plurality of projecting rods of
rectangular
cross section which define the channel 16. After the injection of the foam and
the
molding of the foam material into the required shape, the rods forming the
channel
16 and the bar forming the groove 22 are pulled outwardly from the top face of
the
block to complete the molding of the hollows within the block defining the
groove 22
and the channel 16. Preferably similar insert rods are provided at the
opposite end
forming the bottom 35 of the block 10 so that the rods forming the channel 16
extend
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only over one half of the length of the channels allowing them to be pulled in
opposite directions from a junction point half way along the channels.
This shape-forming process in which the panels are molded including
the molding of the channels and grooves provides a high efficiency forming
system
in which the whole structure is formed in one molding action without the
necessity for
cutting elements from the foam. Wire cutting systems require the necessity for
an
inlet and exit slot which are not necessary in the structure of the present
invention.
The channels 16 are arranged in a common plane and directly aligned.
The channels 16 have an inner surface 16A and an outer surface 16B. The groove
22 is arranged so that one end of the side portion 22C terminates at a
position
coincident with the side 16A of the channel 16. The groove 22 has a width
greater
than the width of the channel between the surfaces 16A and 16B. Thus the apex
22D is located at a position generally aligned with the surface 16B. Thus the
portion
22B extends from the apex further outwardly of the surface 16B toward the
outer
surface 33. In this way, the cross sectional area of the groove 22
approximates to
the cross sectional area of the rectangular channel 16 to provide
approximately a
similar cross sectional area for transmission of water vapour therethrough. It
is clear
that the amount of water vapour transmitted is generally proportional to the
cross
sectional area so that sufficient cross sectional area is provided both in the
channel
16 and in the groove 22. Thus the groove 22 has a width at least equal to the
width
of the channel 16 and preferably greater in view of the triangular shape. The
location fo the groove at the surface allows water vapor to migrate from one
vertical
channel in one panel to one in the next without the necessity to align the
channels in
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the panel assembling process.
The groove and the channels are arranged closer to the inner surface
32 than the outer surface 33 in order to ensure that moisture preferentially
enters the
channels rather than reaches the exterior surface 33 where damage can be
caused.
As shown in Figure 6, the top and bottom surfaces indicated at 34A
and 35A include a ship-lap section generally indicated at 40 wherein there is
a
surface 41 which extends parallel to the inside and outside surfaces 32 and
33.
Thus the surface 34A is divided into a first portion 34B and a second portion
34C
and similarly the surface 35A is divided into a first portion 35B and a second
portion
35C. Between these two portions is the surfaces indicated at 41. The groove
indicated at 22X is formed from the portion 34C of the block 10. A further
groove
22Y is formed in the surface 41 between the portions 34C and 34B. The groove
22Y
thus further acts as trap for moisture tending to migrate along the surfaces
34A and
35A. This trap thus acts to collect water vapour and to transmit that water
vapour to
discharge. It will be noted that the groove 22X is the same width as the
channel 16.
An additional groove can be provided in the vertical sides of the block
again to act as a trap for any moisture migrating between the blocks.
While a particular embodiment of the present invention has been
described in the foregoing, it is to be understood that other embodiments are
possible within the scope of the invention and are intended to be included
herein.
Thus, while the embodiment illustrated in Figures 2 and 3 includes fifteen
equally-
spaced channels 24 per building panel 10, but it may be preferable to have
nineteen
or some other number of channels 24 depending on the application.
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While particular substrates have been identified in the foregoing, it is to
be understood that the application of the panel to any substrate is to be
considered
within the scope of the invention. Currently it is considered that the
invention may
not be especially useful with certain types of substrate, including oriented
strand
board and chipboards. It will therefore be clear to those skilled in the art
that
modifications of and adjustments to this invention, not shown, are possible
without
departing from the spirit of the invention as demonstrated through the
exemplary
embodiment. The invention is therefore to be considered limited solely by the
scope
of the appended claims.
