Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FIELD OF THE INVENTIO~
The invention relates to a drainage system
which can be formed over a horizontal surface that
supports certaln structure through which water may
be expected to travel.
BACKGROUND OF THE INVENTION
The present invention has specific (though
not exclusive) application to building structures
in which a generally horizontal concrete slab supports
a deck constructed of panels of marble, concrete or
the like. In such a structure the deck is normally
spaced from the concrete slab by a layer of gravel.
The gravel is intended to provide a generally level
horizontal surface for resting of the deck (the con-
crete slab perhaps being contoured for reasons
described below) and also facilitates drainage of any
water towards a drain or outfall location. A
particular concern in such construction is to prevent
leakage of water into cracks in the concrete.
Conventional practice is to apply a water-
proofing membrane to the concrete slab prior to
depositing the gravel and the panels of the deck. In
typical applications this procedure involves applying
a primer to the surface of the concrete slab followed
by application of a bonding coat which is typically
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hot asphalt. Overlapping layers of felt are laid on
the bonding coat and a flood coat of hot asphalt is
applied to the felt during on-going construction work.
A layer of thick asphalt felt is applied to the resulting
membrane to prevent damage from an overlying layer oE
gravel.
The procedure described is fairly typical
and in most instances the only variation is in the
construction of the water-proofing membrane. Some-
times a primer is applied to the surface of the concreteslab followed by a rubberized asphalt or synthetic
material which provides a more flexible membrane capable
of accomodating some mov~ment of underlying structure.
Concrete slabs have been overlaid with sheets of
modified rubber or synthetic material with approp~
riate joint treatment to prevent passage of water. A
less common practice is to use a sheet me-tal cladding
formed, for example, of copper. In all such variations
horizontal drainage of accumulating water is typically
through the spaces of an overlying gravel layer.
In the past, it had been common practice
to allow accumulating water to rest directly on the
water proofing membrane of the concrete slab. Problems
have been associated with such a practice, in particular
the tendency of water to permeate the water-proofing
membrane at weak points especially if any substantial
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head oE water pressure develops. Consequently, it is
now common practice to attempt to lead water away from
the surface of the concrete slab by sligh~ly inclining
the surface or contouring the surface to direct water
to the edge of the slab or to drains provided in the
concrete slab.
BRIEF SUMMARY OF THE INVENTION
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In a first aspect, the invention provides
drainage panel having a first network of intersecting
grooves formed in one face of the panel to place each
side edge of the panel in fluid communication with
the other side edges. A second network of intersecting
grooves formed in the opposing face of the panel also
places each of the side edges in fluid communication
with the other side edges. The first and second net-
works are in fluid communication at a multiplicity of
points so that water can flow between the opposing
faces of the panel and in particular between the
networks of grooves.
In a second aspect, the invention provides
a drainage system which can conduct water horizontally
atop a generally horizontal surface such as that
defined by concrete slab. The drainage system in-
cludes a cladding formed of a multiplicity of panels
of the type described above in edge-to-edge abutted
relationship with water able to flow between abutted
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side edges. In a preferred embodiment, the panels of
the drainage sys~em are covered with a water-pervious
filter material which prevents entrainment of dirt into
-the drainage system. Additionally, the panels are pre-
ferably constructed of an insulating material so thatsubjacent structure is protected to some degree from
external temperature variations. Various applications
illustrating the benefits and advantages inherent in
such drainage system are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
- The invention will be better understood
with reference to drawings in which
Fig. 1 is a fragmented perspective view of
a drainage panel constructed according to the invention;
Fig. 2 is a bottom plan view of the drainage
panel;
Fig. 3 is a fragmented view along the lines
3-3 of Fig. l;
Fig. 4 is a vertical cross-sectional view
of a building structure incorporating drainage panels
of the type of Fig. l;
FigO 5 is a vertical cross-sectional view of
the building structure of Fig. 4 with the panels used
in an alternative manner;;
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FicJ. 6 is a fragmen-ted perspective view
from above -the building structure of Fig. 3; and
Fig. 7 is a vertical cross-sectional view
of panels constructed according to the inven-tion in
landscaping applicationO
DESCRIPTION OF PREFERRED EMBODIMENTS
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Reference is made to Fig. 1-3 which illustrates
a :Eirst em~odimen-t 10 of a drainage panel constructed
of expanded polystyrene. The drainage panel 10 has a
generally rectangular shape with a pair of opposing
faces 12, 14, a first pair of opposing side edges 16, 18
~ and a second pair of opposing side edges 20,22. The
face 12 is formed of a first criss-cross network of
intersecting grooves. The first network consists of a
first set of parallel grooves 24 (only one typical groove
specifically indicated) and a second set of parallel
grooves 26 (only one typical groove specifically
indicated) which are perpendicular to the first set of
grooves 24. It will be apparent that the first and
second sets 24, 26 of grooves place each side edge of the
panel in fluid communication with the other side edges.
In Fig. 2, the face 14 of the panel 10 is seen
to have a second network of grooves of similar con-
figuration. The second network consists of a first set
28 of parallel grooves and a second set 30 of parallel
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grooves which are perpendicular to the first set of
grooves 28 (only one groove of each se-t specifically
indicated). It will be apparent that the second network
of grooves also places each side edge of the drainage
panel 10 in fluid communication with the other side
edges.
Each side edge of the panel 10 has a longitud-
inal recess, such as the recess 32 indicated in Fig. 1.
Each recess is in fluid communication with the recesses
of the second network of grooves. The object in pro-
viding such recesses is to ensure that the second net-
work of grooves of any panel can be readily placed in
fluid communication with that of a second, identical
panel abutted at one side edge without concern for
perfect alignment of grooves. This is not a critical
consideration with the first network of grooves which
are intended to reside in the upper surface of a
cladding layer formed of abutted panels and which
will probably not be required to transfer large
quantities of water horizontally. I~owever, the second net-
work of grooves ~ay be required to convey large quantities of water
as will be more apparent with the description below of particular
applications for panels such as the drainage panel 10.
The depth of the grooves in the drainage
panel 10 is of some significance. The first network
of grooves has a substantially uniform depth "a" which
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is lndicated in the view of Fig. 3. The second net-
work of grooves has a substantially uniform depth "b"
also indicated in the view of Fig. 3. The sum of the
depths a and b is greater than the spacing between the
opposing faces 12, 14 so that the first and second
networks of grooves intersect at a multiplicity of
points, such as the point 34 indicated in Fig. 2. In
the drainage panel 10, parallel grooves of each of the
first and second networks are spaced apart by about
three inches cen-tre-to-centre. As between the first
and second networks, parallel grooves are spaced apart
by one and one-half inches. This relative horizontal
displacement of the grooves of the first and second
networks ensures the integrity of the panel 10.
A cover 36 ~fragmented in Fig. 1) of
spun-bonded polyproplyene ~or any other suitable water-
pervious filter material) is secured to the face 12
of the drainage panel 10, over the first network of
grooves. The cover 36 can be attached by any suitable
method depending on the materials involved, including
adhesive bonding, heat bonding or mechanical attachment.
A preferred method (~hown on the panels of Fig. 7) is to form
slits in the side edges of the panel and to wedge edge portions
of the cover in-to the slits. The general object of
providing the cover 36 is to ensure that dirt entrained
with water travelling from the face 12 to the Eace 14
does not ultimately clog the drainage panel 10 or par-
ticularly a drain to which the drainage panel 10 or
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similar panels are coupled. As an alternative, when a
cladding layer is formed of pan~ls such as the drainage
panel 10, a cover of suitable filter material may be laid
over the upper sur~ace of the layer and secured in any
convenient manner.
Fig. 4 illustrates a particular application
for drainage panels similar to the panel 10, involving
a structural slab 38 which supports a deck 40 constructed
of rectangular panels 42 of concrete or any other desired
material. Such a structure might typically be a terrace
provided above a parking garage, the concrete slab forming
the ceiling of the garage. The concrete slab 38 has a
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generally horizontal surface 44 which is contoured or
inclined (exaggerated in Fig. 4) to cause water to
flow towards a drain 46. A water-impermeable membrane
48 of any suitable matexial is formed over the surface
46 to prevent penetration of the concrete by water,
and extends partially into the drain 46 where it is
held by a conventional compression ring 50 bolted to the
drain 46. A protective layer 52 of any suitable conven-
tional material is laid over the membrane 48 to prevent
abrasion or puncturing. A layer of gravel 54 is laid
over the protective layer 52 to provide a more horizontal
surface for laying of the deck 40. Immediately atop
the gravel layer 54 is laid a drainage cladding 56 of
panels such as the drainage panel 10 in edge-to-edge
abut-ted relationship. The nature of the cladding 56
will be more apparent f.rom the view of FigO 6 in which
the deck 40 has been partially broken away to show two
panels 58, 60 of the cladding 56. A cover 62 of water-
impervlous filter material covering the drainage cladding56 has been Eragmented at 64 to better illustrate the
panels. A layer oE mortar 65 is applied to the cover
62 and the deck panels 42 are set and levelled in the
mortar.
The drainage cladding 56 provides two functions
or advantages. First, it replaces a conventional layer
of insulation which is commonly required by structural
engineers to protect an underlying concrete slab from
exposure to extreme temperature variations. Second,
in applications where such an insulating layer immediately
below a deck is required, the cladding 56 reduces the
thickness of gravel required. At a peak in the concrete
slab 38, conventional practice dictates that a thickness
of gravel not less than about one and one-half inches
be provided to ensure proper horizontal drainage of
water. Because the panels of the cladding 56 permit
horizontal drainage of water, the cladding 56 may be
made to rest directly atop the peak in the concrete
slab 38, thereby reducing the requirement for a thicker
gravel layer. This reduction in height required can
contribute to a reduction of the amount of excavat.ion
required in a particular construction site and in some
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applications can significantly assis-t in meeting height
restrictions imposed on particular construction. The
grooves of the panels may cause some reduction in the
insula-ting value of the cladding 56, but spaces between
more conventional insulating sheets would also reduce
their effectiveness, and the cover 62 of filter material
can to a certain extent compensate.
Fig. 5 illustrates another application for
drainage panels similar to the panel 10, which makes better
use of the drainage and filtering functions of the panels. Much of the
structure illustrated in Fig. 5 is identical to that of
Fig. 4, and consequently like components have been
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labelled with like reference numerals. In this particular
applieation, the rela-tive positions of the gravel layer
54 and drainage cladding 56 have been interchanged. The
eladding 56 is now located direetly atop the membrane
48 eovering the eonerete slab 38. The proteetive layer
52 has been eliminated as the drainage cladding 56
proteets the membrane 48 from eontact with the gravel
layer 54. Beeause of the seeond network of drainage
grooves in each panel, water aecumulating at the membrane
4& ean in typieal applieations flow substantially freely
towards the drain 46. In this applieation, the eover
62 removes not only dirt entering from above the deek 40
but also any dirt entrained from the gravel layer 54. It
will be appreeiated from Fig. 5 that the term "generally
horizontal" as used in the speeifieation and in the
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appended claims contemplates surfaces which are not
perfectly horizontal, and contemplates surfaces which
may be inclined or contoured to assist in drainage.
The drainage panel 10 is preferably constructed
oE a material wi-th insula-ting qualities, semi-rigid, and
suitable Eor underground service, such as a synthetic
resln material. The dimensions of the drainage panel 10
may typically be 32 inches by 48 inches by 3 inches, with
roughly 3 inches spacing between parallel grooves, but
these dimensions are exemplary only, and the dimensions
may be appropriately selected for any particular
application.
A preferred embodiment of a drainage panel
and certain applications having been described, it will
be appreciated that certain advantages can be attained
over prior art practices. In many instances, construction
height requirements can be reduced because a layer of
panels can simultaneously provide a measure of insulation
(which must otherwise be provided by an insulating cladding)
and the drainage functions of a corresponding thickness
of gravel. With a cover of fil.ter material the panels
can reduce the entrainment of dirt particles into drains
thereby obviating costly potential blockages. In some
applications the panels can replace a protective layer
normally placed over the water-impermeable membrane commonly
applied to a concrete slab thereby eliminating construction
materials and permitting an additional reduction of height
requirements.
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Another application contemplated for the drain-
age system is in landscaping over a structure such as a
parking garage or indoors. A typical application of
this nature is illustrated in Fig. 7 in which a garden
70 is shown supported above a concrete slab 72 (inclina-
tion exagqerated) which might constitute the ceiling of
an underground parking garage. A waterproofing membrane
74 is applied to the top surface of the concrete slab
72, and a drainage cladding 76 is rested on the water-
proofing membrane 74. The cladding 76 is similar to thosedescribed above, constructed of a multiplicity of in-
dividual drainage panels in edge-to-edge abutted relation-
ship. The panels of the cladding 76 are similar to the
panel 10 except in the manner in which filter material
lS is applied to the panels. In a panel 78 (which is
typical), longitudinal slits have been formed along the
side edges of the panel, intermediate of the opposing
faces of the panel, and edge portions of a rectangular
sheet 80 of spun-bonded polyproplyene have been
wedged into the slits to secure the sheet 80 to
panel 78. A typical longitudinal slit 82 is illustrated
at a side edge 84 of the panel 78 where the sheet 80
has been removed for purposes of illustration. The
wedging of edge portions of the sheet 80 into the slits
of adjoining side edges is apparent at 86, 88. A
significant difference between the panel 78 and the panel
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10 is that the side edges of the panel 78 are not under-
cut to assist drainage between adjacent abutted panels~
Instead, the thickness of the sheets of filter material
overlapping side edges of the panels ensures that grooves
are provided between adjacent panels, such as the groove
90. ~ soil bed consisting of a layer of topsoil 92
supported by a layer of subsoil 94 is deposited directly
on the cladding 76. Those familiar with the landscaping
arts will appreciate that a gravel layer normally
supporting the subsoil layer 94 has been eliminated.
The drainage function normally performed by such a
gravel layer is provided by -the cladding 76. The cladd-
ing 76 also replaces layers of insulation and protection
board which might normally be located on the water-
proofing membrane 74. The drainage system can belocated over a horizontal surface where a garden is to
be provided and dirt then deposited on the covering
material of the drainage system to serve as a bed for
plants. In such instances, entrainment of dirt with
water that flows into any drains provided is particularly
critical. The drainage system ensures that water can
be conveniently drained from the bed without risk o~
blockages.
It will be appreciated that particular embodi-
ments of a drainage panel and drainage system have been
illustrated, and that modifications may be made therein
without departing from the spirit of the invention or
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the scope of the appended claims. For example, the
grooves of the drainage panel 10 may be more closely
positioned (for example at a spacing of one and one-
half inches centre-to-centre~ to render the panel 10
more flexible. The panel can then be made to conform
more readily to a curved surface immediately atop a
concrete subway tunnel. A cladding formed of such
panels contoured to the surface of the subway tunnel
during construction would facilitate drainage of
water to sidewalls of the subway tunnel where a
vertical drainage system could then be used to remove
the water. This is one particular application contem-
plated by the inventor for the present invention.
It will also be appreciated that the term
"generally horizontal" as used in this disclosure and
in the appended claims contemplates the general plane
of a structure or surface being inclined from a
perfectly horizontally orientation, and the term should
be understood primarily in contradistinction to vertical.
