Note: Descriptions are shown in the official language in which they were submitted.
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, 1 SHOWER PAN AND METHOD OF CONSTRUCTION
4 SUMMARY OF THE INVENTION
A shower pan which forms a base of a shower stall has a one
6 piece drain surface which is capable of being built in various
7 sloping configurations. The shower pan i8 preferably constructed
8 oi wood as a prefabricated unit and includes 8 top drain panel
9 supported by graduated 3hims and perimeter strips which are in
turn mounted on a planar foundation. Sets of graduated shims are
11 secured to the foundation in space relation Jo each other,
12 surrounding an oversize drain opening. Perimeter strips are
13 positioned along the outside edges of the foundation. The
14 preferred embodiment of the shower pan illustrates a top drain
panel which is supported by two evenly spaces sets of shims
16 concentrically surrounding a centrally located drain opening. The
17 top drain panel is cut to the same contour as the foundation and
18 is preferably made of plywood. A drain opening in the panel is
19 cut concentrically with the opening in the foundation. A rear
member, side members and threshold melnbers are secured to the top
21 drain panel along its outside edges to provide lateral water
22 barriers. The side members and rear member preferably have inward
23 sloping races while the threshold members are vertical, positioned
24 perpendicularly to -thè top drain panel. The top drain panel is
scored with kurfed relief lines to permit the panel to bend to
26 form a basin like drain surface with the section of the drain
27 panel which surrounds the drain at the lowest elevation. The
28 kerfed relief lines, which define sloping panel sections, are in
29 the form of at least two concentric, straight lined, polyp7onal
cuts which are substantially identical in shape and have their
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1 corresponding vertices connected by radial relief lines. The top
2 drain panel is positioned on the perimeter strip and shiTns and
3 pressed down to form the sloping drain basin. Outer wall panels
4 are then secured to the side and back of the shower pan.
Waterproof resin or filler may be applied to the exposed break
6 lines, though the preferred embodiment include3 break lines which
7 are cut on the bottom surface of the top panel. The entire
8 interior suriace oi- the shower pan i8 covered with a waterproof
9 material such as hot mop tar. An adhesive it then applied to all
exposed surfaces and a finished coverlng such a ceramic tile or
11 cultured marble is applied.
12
13 BRIEF DFSCRIPTION OF THE DRAWINGS
14 Figure l is a perspective view of the preferred embodiment of
the shower pan.
16 Figure 2 is a sectional view taken along line 2-2 of figure
17 l.
18 Figure 3 is a sectional vlew taken along line 3-3 of figure
19 1 .
Figure 4 is a top plan view illustrating the shower pan with
21 a portion of the interior surface with a finish covering and with
22 a portion of the drain panel broken away.
23 Figure 5 is a perspective sectional view of the drain panel
24 inverted and in the flay condition, prior to bending, illustrating
the location of the kerfed relief lines.
26 Figure 6 is a perspective sectional view of the top of the
27 drain panel in the for~ned condition.
28 Figure 7 is an enlarged, partlal sectional view taken along
29 the line 7-7 of figure 4.
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1 DETAILED DE5CRIPTION OF THE TNVENTION
2 A shower pan 10 which forms a base of a shower stall has a
3 one-piece drain surface whlch is capable of being built in various
4 sloping configurations. The shower pan is preferably constructed
of wood as a prefabricated unit to be adapted to an existing
6 shower installation or installed in a new shower installation.
7 The shower pan is constructed of a top- drain panel 12 supported by
8 ¦ graduated shims and perimeter trips which are in turn mounted on
9 ¦ a planar foundation 14. The preferred embodiment i5 illustrated
l0 ¦ in figures 1 through 7.
ll ¦ The shower pan 10 has a planar foundation 14 preferably made
12 ¦ of 3/4 inch plywood, although materials such as other fiberous
13 ¦ materials may be used. The foundation i8 cut to the desired size
14 ¦ and shape of the overall shower pan. An oversized hole 16 is cut
15 ¦ through the foundation to receive a drain fixture 18.
16 ¦ Perimeter strips 20 are positioned along the outside edges of
17 I the foundation and secured to the foundation preferably with
18 ¦ plasterboard screws. The width of the perimeter strips are such
l9 ¦ that they are wider than the side members 22 and 24, back member
20 I 26, and the combined width of the threshold members 28 and 30
21 ¦ described below.
22 ¦ One or more sets of graduated whims are positloned on the
23 ¦ foundation in spaced relation to each other and the perimeter
24 ¦ strips 20 and surround the drain opening 26. The shims are
25 ¦ preferably attached with glue and plasterboard screws to the
26 ¦ foundation. The shims, combined with the perimeter strips,
27 ¦ provide support for the drain panel 12. The preferred embodiment
28 ¦ illustrated in the drawings has a centrally located drain 18 and
29 ¦ the drain panel 12 is supported, in part, by two sets of shims 32
30 ¦ and 34 spaced evenly between lines 46 and 50 which are described
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1 below. The shims 32 and 34 concentrically surround the drain
2 opening 26. The height of the shims 32 and 34 relative to the
3 perimeter strips 20 and to each other may vary according to the
4 desired slope of the drain panel 12, wlth at least a 1/2'l slope
per foot being preferred
6 Vent holes 36 preferably are cut through the foundation as
7 shown in fig. 4 Jo prevent condensation from developing between
8 the foundation 14 and the drain panel 12.
9 The drain panel 12 is cut to the same contour and size as the
foundation or, preierably slightly larger than the foundation. It
ll is preferably cut from a sheet of 1/2" plywood. Like in the
12 foundation, other materials may also be used. A drain opening is
13 cut through the panel, concentrically positloned with the opening
14 in the foundation, for closely receiving the drain fixture 18.
Side members 22 and 24, rear member 26~ and threshoLd members
16 28 and 30 provide lateral water barriers. The side members 24 and
17 26 and rear member 26 preferably have inward sloping faces 38, 40,
18 and 42 cut to a 17-1/2 degree angle as shown in figs. 2 and 3.
19 The threshold members are preferably formed by a pair of parallel
two by fours. Longitudinal glue receiving grooves 44 are cut into
21 the bottom of the side members, threshold members, and the rear
22 member.
23 The top drain panel 12 is scored with keried relief lines to
24 permit the panel to bend to form a basin-like drain surface with
the section of the drain panel which surrounds the drain at the
26 lowest elevation. The relief llnes are preferably scored on the
27 bottom surface of the panel, but they alternately can be placed on
28 the top surface. The kerfed relief lines are formed by cutting,
29 preferably halE way through, the drain panel from the bot tom. The
kerfed relief lines are in the form of at least two concentric,
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1 straight lined, polygonal cuts which are substantially identical
2 in shape and have their corresponding vertices connected by radial
3 relief lines. A suggested and preferred method ior constructing
4 and forming the kerfed drain panel is illustrated by the preferred
embodiment. An outer rectangular relief cut 46 is made at a
6 position in from and parallel to the outside edges of the drain
panel at a dlstance intermediate to the width of the perimeter
8 strips below and the corresponding side, back or threshold member
9 above. This cut defines what will become an upper elevated
sectlon 48 of the panel along the outside edges. The inner relief
2 cut 50 is an approximately 7x7 square which surrounds the drain
opening. The sides of the inner relief cut are parallel to the
13 sides of the outer relief cut and to the outside edges of the
14 panel. The inner relief cut defines what will become a lowered
section 52 around the drain at the lowest point on the panel.
16 Radial relief cuts 54 are scored between and connecting the
17 corners of the inner and outer rellef cuts in the drain panel,
18 defining what will become the sloping panel sections 56, 58, 60,
19 and 62. Since the outer relief cuts are positioned inside the
edges of the perimeter strlps 20, the perimeter strips will
21 support the loads on the sloping panel sections near the outer
22 relief cuts.
23 The side members 22 and 24, rear member 26, and threshbld
2~ members 28 and 30 are secured to the perimeter of the draln panel,
using an adhesive ln the grooves 44, such as epoxy or glue, and
26 plasterboard screws.
27 To form the sloped drain basin from the drain panel an
28 adhesive, such as glue is applied to the top surfaces of the
29 graduated perimeter strips and shims. Additional support for the
drain panel may be provided by applying viscous material 64 such
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blobs of portland cement the surface of the foandacion
2 ¦ beneath the positions of the radial relies cuts 54. The top drain
3 panel 12 is then set onto the perimeter strips t centrally alligned
4 with the outer edges of the foundation and pressed down onto the
shims, perimeter strips, and viscous material and so that the
6 lowest section of the panel 52 i8 in communication with and
7 supported by the top surface of the planar foundation as shown in
8 ¦ figs. 2 and 3. The outside edges ox the foundation 14 and the top
9 l panel 12 are no,w vertically alligned due to` the slightly overslzed`
lO 1 dimensions of the previously flat drain panel,
ll ¦ Where the side members and rear members are made of more
12 ¦ rigid materials, such as heavier lumber or multiple members, the
13 ¦ drain basin should be formed before the side members, rear member
14 ¦ and threshold members are attached. If these members are too
15 ¦ rigid such that their centers cannot Alex somewhat and they are
l6 ¦ attached before formation of the basin shape the drain panel tends
17 ¦ to ail structurally along the relies lines. The failures tend to
18 ¦ occur particularly in the center of the outer relief cut along the
19 ¦ outer sides of the sloping panel sections if these lateral water
20 ¦ barriers are to rigid. The same type ox structural failure will
21 ¦ occur if the upper elevated section 48 is too wide or thick and
22 ¦ therefore not flexible enough.
23 1 While a centrally located drain opening with concentrically
2~ l positioned shims is lllustrated in the drawing, the openings and
may be placed anywhere in the panel. Such placement will vary the
26 angle of the panel sections of the drain panel and positioning and
27 sizing of the shims under each panel section. however, the drain
2~ opening cannot be placed too close to an edge ox the drain panel.
29 Normally there should be at least ten inches or more space between
the inner break line 50 and the outer break line 46.
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I Outer wall panels 66, 68 and 70 are ehen secured wlth an
2 ¦ adhesive, such as glue, and plasterboard screw to the sides and
3 ¦ back of the shower base. They extend from the bottom of the
4 ¦ foundation to above the top of the side walls. The outer walls
5 ¦ may be made of a fiberous material, such a plywood or hardboard.
6 ¦ Waterproofing is achieved firs by filling the exposed break
7 1 lines 48, 50, and 54 with a waterproof resin or other filler if
8 ¦ the relief lines were cut in the top surface of the drain panel
9 12. If the relief lines were cut in the bottom surface they need
not be filled. The entire interior surface of the top drain panel
ll is then covered with a water proofing materlal such as hot mop
12 tar.
13 The structure resulting from the above described methods of
14 constructlon results in a shower pan which has sharply angled
corners. Such a structure is most desirable when ceramic tile or
16 cultered marble is applled to the interior surfaces and the
17 threshold of the shower pan. By way of contrast, shower pans
which are molded of plastic, Fiberglass resin or similar materials
l9 or made of formed metals generally have rounded corners which are
unsuitable for use with such lining materials.
21 An adhesive is then applied to all exposed surfaces and a
22 finish covering such as ceramic tile 72 or cultured marble is
23 applied to the interior surfaces of the shower pan and the
24 threshold. To ensure proper fitting of the sections of tile or
marble, the side members, rear wall, or threshold members may be
26 shimed to accommodate the width of tile segments.
27 tr~c~n~rk
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