ONE-PIECE SILL PAN FLASHING

FIELD OF THE INVENTION

[0001] The invention relates generally to the field of home and office construction and more particularly to a novel and improved sill pan flashing for installation at the bottom of the rough framing of a window or door opening in order to prevent penetration of water underneath a window or door unit and into the underlying framing structure.

BACKGROUND OF THE INVENTION

[0002] In the home construction industry, it is typical for windows and doors to be constructed as independent, prefabricated units and installed in framed openings constructed in the exterior walls of the home. The exterior framing of typical prefabricated window units, for example, overlaps the exterior of the housing wall around the framed openings and initially is sealed to prevent access of moisture. Over time the sealing material may deteriorate and allow some moisture to penetrate. This can result in deterioration of the wood framing and of housing structure below the framed opening.

Accordingly, in many such structures it is the practice to install a sill pan flashing between the bottom of the prefabricated window unit and the underlying sill plate of the framing. The sill pan flashing is formed of a suitable plastic or metal material and serves to direct any collected water outward to the exterior of the siding. Examples of such sill pan flashing devices are shown in U. S. Patents No. 1 ,677, 130, No. 7,222,462, No.

7,673,426, and No. 8,443,554. A typical framed window opening includes a horizontal sill plate and spaced apart vertical elements, joined to opposite ends of the sill plate and extending upward therefrom. The upper ends of the vertical elements are joined to a header member, which extends horizontally between the vertical members and forms a closed opening, usually of rectangular configuration, in which a prefabricated window unit can be received. The elements comprising the framed opening typically may be formed of 2" x 4" lumber. In addition, a rough siding typically is secured to the exterior framing of the structure, and an opening is cut into the rough siding in the size and shape to coincide with the framed opening. The rough siding may be of ½" or ¾" plywood, for example.

[0003] A sill pan flashing of typical construction includes a sill cover arranged to extend over the full width of the sill plate. The sill cover is tilted forwardly to allow water to drain forwardly toward the exterior of the structure. Typically, a front structure extends downward a short distance at the front of the sill cover to guide the flow downward over the outer surface of the finished structure. A front flange or panel of the flashing typically extends laterally a few inches beyond the sides of the opening so as to cover a small front area of the rough siding. Portions of the front panel also extend upwardly a few inches above the level of the sill plate at each side of the opening. Side panels also extend upward a few inches from each end of the sill cover and overlie lower portions of the vertical framing members. The side panels are joined at their front vertical edges with the upwardly extending portions of the front panel to form relatively rigid (i.e., self-supporting) corner structures at opposite sides of the framed opening.

[0004] It is standard construction practice to dimension rough-framed window openings to dimensions somewhat larger than the standard dimensions of the prefabricated window units to be inserted therein. Window manufacturers recommend that the opening defined by the framing be a half to three-quarters inch larger than the nominal size of the prefabricated window unit. In actual practice it is common for the dimensions of the rough framing to vary significantly from the recommended tolerances, anywhere from a half to three-quarters inch smaller to more than an inch larger than recommended. This presents a problem with respect to the installation of the sill pan flashings, because the required width of the flashing, in order to fit snuggly between the vertical elements of the frame, may be different for each of many framed openings that are "nominally" of the same size. Heretofore, this commonly has been dealt with by forming the sill pan flashings in two or three (sometimes more) pieces, which are assembled in the field to fit the individual openings. A two-piece assembly, for example, is made to fit the largest opening expected to be encountered in the field for a given nominal size window unit. Thus, a conventional two-piece sill pan flashing, intended for a window unit of nominal 24" width, is dimensioned so that the pieces have a total width substantially greater than the anticipated maximum opening of 25.5", enabling the two pieces to be assembled in the field in partially overlapping relation to fit a range of opening sizes. Typically, a sealant is applied in the field where the two pieces overlap, to avoid leakage at the interface between the parts.

[0005] The above described procedures, while enabling the flashing to be fit suitably to the framed opening, have important disadvantages. Among others, the individual installation of the two (or more) components, and the sealing of the interface(s) between them consumes extra labor time and thus adds to the cost of construction. Also, a sealant is required to seal the joint where the sill pan has more than one piece, and such sealed joints are often installed without the proper skill and care and are notorious for enabling leakage over time. The ASTM Manual relating to multi-piece flashing contains the statement at Section 5.16.4.2, "Warning— Sealant selection and application are critical to performance***."

[0006] It has been proposed heretofore to fabricate a sill pan flashing in one piece, sized suitably at a width greater than the maximum expected width of the rough opening. Such a proposal is found in the Broad et al. US Patent 7,673,426. Although the proposed one-piece flashing can be shipped to the job site as a single unit, it must be cut into two parts at the job site in order to fit the opening. The then two-piece assembly is overlapped and sealed during installation in the same manner as the above-described multi-piece assemblies, with all the disadvantages thereof, and with the addition of the cutting operation and the requirement of the necessary tools to perform the cutting operation.

[0007] There thus remains a long-felt need for an improved form of sill pan flashing that can be fabricated, shipped and installed in one piece with attendant reduction in labor costs and inventory issues, and with greatly improved performance with respect to leakage over time.

SUMMARY OF THE INVENTION

[0008] Pursuant to the invention, a novel and improved form of sill pan flashing is provided, which is fabricated in one piece, delivered to the job site in one piece, and installed in the window framing in one piece, with resultant savings from various sources, but with particular benefits in labor costs at the job site as well as superior performance derived from the absence of need to seal an interface between individual parts. The device of the invention comprises end structures at each side arranged to be seated against lower portions of the vertical elements of the framing, and a sill plate cover joined with the end structures and forming therewith a continuous sill cover.

Pursuant to the invention the sill plate cover of the sill pan flashing includes one or more accordion sections configured to allow for a predetermined amount of width adjustment of the flashing to fit the framing. The new flashing may be designed to a width that is greater or less than the width of a framed opening that can receive a prefabricated window unit of a given nominal width. However, the one or more accordion sections integrally incorporated into the sill cover of the flashing accommodate sufficient expansion or compression of the width of the flashing to enable it to be fitted properly to the actual width of the framed opening during installation, regardless of the wide variations in such width typically encountered at the job site. In a typical installation procedure according to the invention, assuming the initial width of the flashing to be less than that of the window framing, one of the end structures is secured tightly against an adjacent vertical member of the frame, for example by nailing or stapling. Then the second end structure is urged laterally, expanding the accordion section or sections until the second end structure engages the opposite vertical member of the rough framing. The second end structure is then fastened in place against the opposite vertical member. Where the initial width of the flashing is greater than that of the framing, the flashing is compressed in width enough to be inserted into the framing, after which the end structures are secured in place on the framing.

[0009] In one advantageous embodiment of the invention, the end structures are formed by injection molding of a relatively rigid plastic material. The central portion can be formed with a suitable thermoplastic material, as by thermoforming or injection molding. The opposite end edges of the central portion are configured to join with the inside end edges of the end structures enabling the end structures and central portion to be permanently bonded as one piece and properly and permanently sealed at the factory. Between its opposite end edges the central portion is formed with one or more accordion sections, with a series of suitably shaped grooves (e.g., V-shaped, U-shaped, sinusoidal, etc.) to allow the central portion to be extended or compressed in the width direction as necessary to accommodate a full range of frame openings that would be encountered in the field.

[0010] In another preferred embodiment of our invention the

construction of the flashing enables it to be either expanded or compressed in width by substantial amounts. A benefit of this characteristic is that the new sill pan flashings can be designed to a particular initial flashing width, with the capability of being either enlarged or compressed in length to fit a range of opening sizes. The improved flashing thus can be installed in rough framing of a range of nominal framing widths, both substantially larger and

substantially smaller than the initial width of the flashing itself. This characteristic enables manufacturers and sellers (typically large "home improvement" stores) to stock a smaller inventory of flashing widths in relation to the more numerous nominal sizes of window and door framing in which the flashings are to be installed. This can be an important advantage inasmuch as a one-piece flashing can be relatively large and bulky and occupy a significant amount of storage space. Since one flashing size according to our invention can be applied to a plurality of window sizes, the required inventory of sizes may be reduced in comparison to what otherwise would be required.

[0011] The preferred sill pan flashing of our invention makes novel use of accordion features sometimes found in the bellows of professional cameras but having special advantages and uniqueness in the particular environment of our new sill pan flashing. For use in a sill flashing, an accordion section must be constructed to have forwardly and downwardly inclined portions, to cover the top of the sill plate, and vertical portions to lead collected water downward over the front of the sill plate and over the exterior of the structure. The accordion section comprises a series of narrow panels, foldably connected along lateral edges thereof forming, when partially folded, a series of ridges and valleys. At the juncture of the horizontal and vertical portions of the accordion sections, the accordion folds are aligned such that the ridges of the inclined portions are aligned with the valleys of the vertical portions (and vice versa). This automatically forms the accordion section with a beveled front corner which is easily received in the limited space between rough framing and the prefabricated window unit. This construction also greatly reduces material stress at the front upper corners of the accordion sections and correspondingly minimizes the risk of weakening the material and compromising the weather integrity of the product.

[0012] In one embodiment of our invention, the accordion section or sections are thermoformed from a single sheet of plastic, and in appropriate cases the entire flashing might be a one-piece, thermoformed unit, preferably formed of a thermoplastic polyolefin material. [0013] In yet another embodiment of our invention, the flashing may be constructed in two parts, for typical window sizes, and in three or more parts for extremely wide window structures, with the flashing parts in all cases being permanently joined and sealed as one piece at the factory. The resulting one- piece flashing includes one or preferably two or more accordion sections to accommodate expansion or compression in width during installation at the job site. Preferably, all sections of the flashing are formed by injection molding of a thermoplastic material.

[0014] The new flashing, in its various forms, is cost effective and functional throughout the manufacturing and sales phases and is uniquely advantageous during installation and for long term protection of the structure in which it is installed.

[0015] For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of the invention together

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Fig. 1 is an orthographic view of a portion of a rough-framed window opening with an embodiment of a one-piece sill pan flashing according to the invention mounted therein.

[0017] Fig. 2 is an exploded view of three components which, when joined as one, make up the one-piece sill pan flashing of Fig. 1 .

[0018] Fig. 3 is an inverted exploded view of the three components shown in Fig. 2

[0019] Fig. 4 is a front elevational view of the sill pan flashing of Fig. 1 . [0020] Fig. 5 is a top plan view of the sill pan flashing of Fig. 1 . [0021] Fig. 6 is a bottom plan view of the sill pan flashing of Fig. 1 . [0022] Fig. 7 is a front elevational view of an end structure forming a part of the flashing of Fig. 1 .

[0023] Fig. 8 is an inside end elevational view of the end structure of Fig. 7, illustrating the end structure as mounted in a rough-framed opening.

[0024] Figs. 9, 10 and 1 1 are outside end elevational, bottom plan and top plan views respectively of the end structure of Fig. 7

[0025] Fig. 12 is an orthographic view from above of an accordion section forming a part of the sill pan flashing of Fig. 1 .

[0026] Fig. 13 is an orthographic view of the accordion section of Fig. 12, inverted to show bottom features.

[0027] Figs. 14 - 17 are top plan, front elevational, bottom plan and end elevational views, respectively, of the accordion section of Fig. 12.

[0028] Fig. 18 is a cross sectional view as taken along line 18-18 of Fig.

15.

[0029] Figs. 19 and 20 are fragmentary cross sectional views as taken generally along lines 19-19 and 20-20, respectively, of Fig. 5.

[0030] FIG. 21 is an orthographic view of a second embodiment of a sill pan flashing according to the invention.

[0031] FIG. 22 is a front elevational view of the flashing of Fig. 21 .

[0032] FIG. 23 is a top plan view of the flashing of Fig. 21 .

[0033] FIG. 24 is an orthographic view showing one end portion of the flashing of Fig. 21 , from behind and underneath.

[0034] FIGS. 25 and 26 are cross sectional views as taken generally on lines 25-25 and 26-26 respectively of Fig. 22, with Fig. 25 illustrating positioning of the flashing with respect to members of a rough-framed window opening.

[0035] FIG. 27 is a greatly enlarged partial front elevational view of the flashing showing details of a small portion of an accordion section thereof, and

[0036] FIG. 28 is an enlarged, cross sectional view as taken generally on line 28-28 of Fig. 27.

[0037] Fig. 29 is an orthographic view of a third embodiment of a sill pan flashing according to the invention formed in two parts and suitable for a 36" window opening.

[0038] Fig. 30 is an orthographic view of one part of a two-part sill pan flashing similar to that of Fig. 29 but suitable for a 24" window opening.

[0039] Fig. 31 is an orthographic view of one part of a two-part sill pan flashing similar to that of Fig. 29 but suitable for an 18" window opening.

[0040] Fig. 32 is an orthographic view of the second part of the two-part sill pan flashing of Fig. 31 , shown in an upside-down orientation.

[0041] Fig. 33 is an end elevational view of the flashing part of Fig. 32.

[0042] Fig. 34 is an end elevational view of a flashing part similar to that of Fig. 34 but configured for a wider (e.g., 6" rather than 4") sill plate member.

[0043] Fig. 35 is a back elevational view of the flashing of Fig. 29 with end parts broken away, showing details the center joint between the two parts of the flashing.

[0044] Fig. 36 is a fragmentary cross sectional view as taken along line 36-36 of Fig. 30. [0045] Fig. 37 is a fragmentary top plan view of one part of a two-part flashing for an 18" window unit.

[0046] Fig. 38 is a cross sectional view as taken generally on line 38-38 of Fig. 37.

[0047] Fig. 39 is an enlarged, fragmentary view of a portion of Fig. 38, showing details of elevated portions of the accordion structure.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0048] Referring to the drawings, and initially to Fig. 1 thereof, the reference numerals 20, 21 designate vertical framing members, frequently 2" x 4" lumber, which form opposite sides of a rough-framed window opening 22 as provided in a typical home under construction. A horizontal sill plate member 23, visible in Fig. 8, extends between the vertical framing members 20, 21 and forms the bottom of the framed opening 22. An upper horizontal member (not shown) extends between upper portions of the vertical framing members 20, 21 and forms the top of the framed opening 22. An outer sheathing 24, typically of plywood, is applied to the outer framing, and an opening 25 is formed in the sheathing to correspond with the framed opening 22.

[0049] Prefabricated window units (not shown) typically are

manufactured to standardized dimensions, to be received in framed openings, which are themselves designed to standardized dimensions. Typically, for a normal sized window unit, the framing is intended to be about ½ to ¾ inch larger than the dimensions of the prefabricated window unit intended to be received in the opening. The prefabricated window unit typically is provided with an external flange surrounding the body of the window. The external flange, when the window unit is inserted into the framed opening 22, extends beyond the edges of the opening 22 and overlies the front face of the sheathing 24. Typically, a protective layer of Tyvek® or the like (not shown) is applied over the sheathing 24 for improved weatherproofing.

[0050] Although the prefabricated window units typically are

manufactured accurately to relatively close tolerances, the same cannot be said for the construction of the framed window openings 22. The window openings are considered rough framing and acceptable tolerances may be up to ½ to ¾" inch smaller than a nominal rough frame width and considerably greater (perhaps an inch or inch and one half wider than the nominal width of a frame intended to receive a typical double-hung window unit), and potentially even more for wider windows, such as picture windows. Thus, for a window unit of nominal 24 inch width, the nominal rough frame width to accommodate the window unit would be 24.5", and the actual frame width encountered in the field likely would range from 24", as a minimum, to 25.5" or more as a maximum.

[0051] Pursuant to one aspect of the invention, a one-piece, variable width sill pan flashing is provided which has sufficient adjustability in the width direction to accommodate a full range of width variations in the rough framing without requiring cutting and fitting on the job site. The designed, at-rest width of the one-piece flashing can be more or less than, a width "W" of the intended prefabricated window unit. At the same time, the one-piece flashing is sufficiently expandable or compressible to enable the width to be adjusted to any frame width that would be acceptable for receiving the prefabricated window unit.

[0052] With reference initially to Figs. 1 - 1 1 , one embodiment of the sill pan flashing of the invention includes left and right end structures 26, 27 joined by a connecting section 28. The two end structures are of the same construction, but of opposite hand, and the description of the left end structure 26 will for the most part apply to the right end structure 27, with corresponding primed reference numerals being frequently used with respect to the right end structure. Referring in particular to Figs. 7-1 1 , the left end structure 26 preferably is an injection molding of a relatively rigid material, such as rigid polyvinyl chloride (pvc) and comprises a front panel 29 of generally L-shaped configuration arranged to be seated against the front face of the sheathing 24. An upper portion 30 of the front panel extends above the level of the sill plate member 23 and a lower portion 31 of the front panel extends laterally across the front a predetermined distance, with its upper edge substantially level with the top of the sill plate 23. A side panel 33 is disposed at right angles to the front panel 29, and the forward vertical edge 34 of the side panel 33 is joined integrally with an inside vertical edge 35 of the upper front panel portion 30 to form a relatively rigid, right angle configuration. The side panel 33 is arranged to be seated against the vertical framing member 20, with the front panel 29 seated against the sheathing 24, as shown in Fig. 1 . The bottom edge 33a of the side panel extends downward to rest upon the sill plate 23.

[0053] A sill cover portion 36 of the end structure is joined integrally at the front with an upper edge 32 of the front panel portion 31 and extends rearwardly and slightly upward therefrom, with its back edge 37 generally aligned with a back edge 38 of the side panel 33. The sill cover portion 36 is joined integrally with lower portions of the side panel 33 such that the entire end structure 26 forms a water-tight structure. As shown in Fig. 2, the sill cover includes an upwardly inclined panel 39, which extends rearwardly from the upper edge 32 of the front panel portion 31 at an angle. Adjacent to the back of the end structure 26, the inclined panel 39 joins integrally with a back support 40 of inverted U-shaped configuration. A forward face 41 of the support 40 extends upward from the back edge of the inclined panel 39 and forms a dam to inhibit he back flow of water resulting from extreme winds. The forward face 41 also can serve as a positioning stop for engagement with a window unit (not shown) when inserted into the framed opening 22.

[0054] The sill cover portion 36 of the end structure also serves to provide structural support for a window unit installed in the framed opening. To this end the inclined panel is formed with a plurality of laterally spaced apart triangular support ribs 42 that extend from the front face 41 of the back support 40 to a position closely adjacent to the front panel 29. The upper surfaces 43 of the ribs 42 lie in a common horizontal plane and are positioned to engage and support the underside of a window unit installed in the framed opening. As shown in Figs. 3 and 10, the underside of the inclined panel 39 is formed with a plurality of reversely oriented triangular ribs 44 which are vertically aligned with the support ribs 42 on the opposite side of the panel 39 such that support of the window unit is transferred through the ribs 42 and 44 and onto the sill plate 23. In the illustrated end structure, a cross rib 45 extends at right angles to and intersects with the ribs 44 to provide additional support. Additionally, the back support 40 has front and back support flanges 46, 47 that extend downward to the sill plate 23 as shown in Fig. 3.

[0055] Although the invention is not limited to specific end structure dimensions, in a representative preferred embodiment of the invention, for a typical standard (e.g., 24") window unit, the front panel 29 may have an overall height and width of about 8 inches and may extend about 4 inches above and below the sill plate 23 and about 4 inches to either side of the inner faces of the vertical framing members 20, 21 . The sill cover portions 36, 36' extend inward for about 4 inches and provide support for opposite sides of a window unit installed in the framed opening 22. For window units of relatively large width, the horizontal portions of the end structures may be extended to provide additional support for the window unit and/or support elements similar in construction to the sill cover portions 36, 36' may be incorporated into the connecting section 28 to provide support for central portions of a window unit.

[0056] As is evident in Figs. 1 and 2, the right side end structure 27 corresponds in all respects to the left side end structure 26 except for being configured on the opposite hand, to extend inward from the right side of the framed opening. In all other aspects the design and function of the right side end structure 27 are identical in all respects to those of the left side end structure 26.

[0057] In accordance with an aspect of the invention, the end structures 26, 27 are permanently joined by the connecting section 28 forming the central portion of the flashing. The connecting section 28 is shown

independently in Figs. 12-18. In the embodiment of the invention shown in Figs. 1 -20, there is one connecting section 28. However, as will be

understood, for horizontally elongated window units, such as for wide picture windows, there can be more than one variable width connecting section and, where appropriate, connecting sections may be joined with one or more sections of fixed length (not shown), some or all of which may be provided with ribs corresponding to the ribs 42, to provide support of an elongated window unit in one or more regions between the end structures 26, 27.

[0058] In the form of the invention illustrated in Figs. 1 -20, the inwardly projecting end of the end structure 26 is formed with a connecting flange 48 comprised of a vertical front section 49 extending parallel to the front panel 29 but offset slightly forwardly thereof, such that the back surface of the front section is substantially on a plane with the front surface of the front panel 29 (see Fig. 8), in which the connecting flange 48' is shown in cross section. An inclined section 50 of the connecting flange extends rearward and upward, at a somewhat lower angle than the inclined panel 39, so as to be generally at the same level as the panel 39 at the rear but offset slightly upward from the inclined panel at the front corner. At the back, the connecting flange has a generally inverted U-shaped section 51 , the outer surfaces of which are offset slightly downward and inward from the corresponding surfaces of the back support 40. An abutment flange 52, 52a extends along the front face 29 and along the inclined panel 39 of the end structure 26 to define the inner edges of the connecting flange 48. The portion 52a of the abutment flange tapers from front to back as the inclined portion 50 of the connecting flange merges with the inclined panel 39 at the back portion 51 . [0059] Referring now to Figs. 12-20, the connecting section 28 is comprised of connecting sockets 60, 61 at opposite ends, transition sections 62, 63 extending inward from the sockets, and an accordion section 64 joined at its opposite ends with the respective transition sections 62, 63. The connecting sockets are configured to closely receive the connecting flanges 48, 48' such that the end extremities of the sockets abut the flanges 52, 52' and the back supports 40, 40' as shown in Figs. 1 and 4-6. Pursuant to the invention, the sockets 60 61 are permanently joined and sealed with the respective connecting flanges 48, 48' at the factory, by adhesives or other suitable bonding procedures, with permanently water-tight seams, such that the resulting one-piece flashing provides a fully effective barrier to water leakage from above, with the water being diverted forwardly to the exterior of the dwelling structure. The flashings are shipped in one piece and installed without the cutting and/or assembling operations required of conventional sill pan flashing devices.

[0060] While the socket portions 60, 61 of the connecting section 28 preferably are sized to closely fit with the connecting flanges 48, 48' of the end structures, the lengths of the respective transition sections 62, 63 and of the accordion section 64 can be varied to suit the sizing and other

requirements of the installation.

[0061] In the form of the invention illustrated in Figs. 1 -20, the accordion section 64 extends between the transition sections 62, 63 and is comprised of a series of connected accordion elements 65 of generally semi- cylindrical cross sectional configuration joined at their outer edges 66 (see Figs. 19, 20). In one exemplary but non-limiting embodiment of the invention, the accordion elements may have an inside radius of about 0.155 inch and an outside radius of about 0.225 inch, with a wall thickness of about 0.070 inch. The total thickness of the accordion section 64 preferably is less than 0.250 inch. The principal requirements are that the configuration of the accordion elements enable a width adjustment of the assembled flashing unit during installation to meet the entire range of expected width variations of the rough framing and that the accordion elements form inclined and vertical flow passages for diverting any accumulated liquid forwardly to the exterior of the structure.

[0062] As shown in Fig. 8, the configuration of the connecting sockets 60, 61 is such that the front portions 67, 68 thereof extend downward along the front face of the sheathing 24, while inclined portions 69, 70 are supported on the front portion of the sill opening in the sheathing. The back portions 71 , 72 of the connecting sockets are configured to conform substantially with the configuration of the supports 40, 40' of the end structures, when the sockets are joined with respective end structures 26, 27. At the front corner of the opening in the sheathing 24, the accordion elements 65 rest directly on the sheathing. Likewise, extending downward along the front of the sheathing, the inner surfaces of the accordion elements 65 lie closely against the front surface of the sheathing

[0063] As reflected in Figs 12, 13 and 16, the semi-circular or other configuration of the accordion elements 65 is maintained throughout the vertically extending front portions 73, the inclined portions 74 and inverted U- shaped back portions 75. This assures that any width extensions or contractions of the accordion section 64 will be substantially uniform and will not result in unwanted distortions.

[0064] The illustrated accordion section 64 may be formed of a flexible plastic material, such as a flexible pvc, and advantageously is formed by thermoforming or other similar procedure. In the illustrated embodiment, the thickness of the material forming the accordion section is approximately 0.70 inch. However, neither the materials nor the method of forming nor the specific dimensions are deemed critical to the invention. All that is required is the ability of the accordion section 64 to be adjusted in width during installation in a rough framed opening, preferably by a single person, without requiring special tools.

[0065] It is not expected that the accordion section 64 or sections will serve in a load-bearing capacity. For window units of smaller sizes, the entire load of the window unit can be borne by the two sill cover portions 36, 36' of the end structures 26, 27. For windows of greater width, such as picture windows, for example, additional sill cover portions (not shown) similar to the sill cover portions 36, 36' (i.e., provided with support ribs to receive the local window load) can be interposed between spaced apart connecting sections 28 or between accordion elements 65 of one or more connecting sections. Regardless of the overall width of the sill flashing unit, all of its components will be bonded together as a one-piece, variable width unit at the factory, and shipped and installed in the window frame as a one-piece unit.

[0066] Referring now to the embodiment of the invention shown in Figs. 21 -28 of the drawings, the numeral 120 designates a sill pan flashing according to the invention which, may be formed in one piece by

thermoforming or injection molding procedures of a suitable plastic material, preferably a thermoplastic polyolefin. For a typical flashing, it is contemplated to utilize plastic material of, for example, about 0.080in in thickness. The flashing 120 is comprised of end structures 121 , 122 at opposite sides and a sill plate cover 123 extending between and joining the spaced apart end structures. The two end structures have front-facing vertical panels 124, 125 joined along vertical edges with laterally inwardly facing vertical panels 126, 127. These panels form rigid corners that are intended to engage and be secured to outer sheathing 1 17 and spaced-apart upright members 1 18 (Fig. 25) of a rough-framed opening of a suitable size and shape (typically rectangular) for the reception of a prefabricated window unit (not shown). The sill plate cover 123 includes a forwardly and downwardly inclined top structure 128 and a vertical front structure 129. When the unit is installed, the top structure 128 will rest upon and cover the sill plate 1 19 of the rough-framed opening while the vertical front portion 129 extends downward over the front of the sill plate.

[0067] In the embodiment of Figs. 21 -28, the sill plate cover 123 includes a pair of accordion sections 130, 131 , to be described further. A central window-support section 132 is located between the accordion sections, and laterally spaced window-support sections 133, 134 are positioned between the accordion sections and the respective adjacent end structures 121 , 122. It will be understood, that a sill pan flashing according to the invention may incorporate more than two accordion sections or only one accordion section, depending upon the size of the rough framed opening and the window unit to be installed therein, and the number and positioning of window support sections may vary correspondingly. Normally, however, there should be window-support sections at each side of the flashing, for the smaller window sizes, with additional support sections provided for larger sizes.

[0068] Substantially the entire upper surface areas of the sill plate cover 123, including the upper surfaces of the accordion sections 130, 131 , are inclined downward and forward at an angle, in order to direct any water to the front of the flashing and downward over the front surfaces thereof. In the window-support sections 132-134 there are also provided pairs of window support ribs 135, the tops of which extend horizontally front-to-back forming a horizontal support on which the sill of a prefabricated window unit may be supported. As indicated in the drawings, and particularly Fig. 26, the tops of the support ribs 135 lie at least a short distance (e.g., 0.17in) above the tops of the accordion sections 130, 131 , at their highest points at the rear of the flashing unit, such that the accordion sections, even if compressed during installation, will not bear any of the weight of the window unit. Preferably, the support ribs 135 are of an inverted U-shaped cross section, open at the bottom, as shown in Figs. 24 and 25, and closed at the front and back to maintain weather integrity. Desirably, the front and back faces 141 , 142 of the ribs 135 are disposed at an inclined angle to better accommodate a thermoforming procedure.

[0069] Extending along the back edge of the flashing in the areas thereof not formed by the accordion sections 130, 131 , are laterally extending elevated ridges 137-139. The elevated ridges, together with elevated back portions of the respective accordion sections 130, 131 (described hereinafter), form an effective dam to prevent the upward and inward flow of water under the pressure of extreme winds. Extending along each lateral side of each of the support ribs 135 is a groove 136 which extends from the front edge of the flashing rearwardly to the ridges 137, 138, 139. The grooves 136 are horizontally disposed (unlike the remaining portions of the top structure 23 which are forwardly inclined). The bottom surfaces 140 of the grooves (see Figs. 25 and 26) are arranged to be seated on the upper surface of the sill plate 1 19 of a rough framed opening in order to properly position and orient the flashing thereon at the desired elevation and forwardly tilted angle.

[0070] In the illustrated embodiment of the invention the accordion sections 130, 131 are integrally formed with the remainder of the flashing, as part of a thermoforming process, although it is contemplated, as with the embodiment of Figs. 1 -20 that the accordion sections may be separately formed, as by molding or thermoforming, and bonded at the factory with the end structures 121 , 122. With reference particularly to Figs. 21 , 24, 27 and 28, the vertical front portions 141 of the accordion sections are comprised of a series of foldably connected narrow panels 142, 143 joined along outwardly and inwardly projected fold lines 144, 145 respectively. The outwardly projected fold lines 44 form "ridges" of the folded accordion structure while the inwardly projected fold lines 145 form "valleys" of the structure. In a representative but non-limiting example, the vertical front portions 141 of the accordion and the adjacent portions of the front structure 129 may extend downward about 4 inches. [0071] As shown particularly in Fig. 28, the molding or thermoforming process is carried out in such manner as to cause the fold lines 144, 145 to be of considerably less thickness than that of the adjacent panels 142, 143 connected thereby. In an exemplary but non-limiting embodiment of the invention, the fold lines may have a thickness of about 0.025in, while the connected narrow panels 142, 143 have a thickness of about 0.085in. This assures that the folding action of the accordion structure is substantially confined to flexing along the fold lines 144, 145 of the ridges and valleys. With the accordion sections in a relaxed configuration, neither extended nor compressed from the as-manufactured configuration, the wave height of the front folds, with the panels 142, 143 disposed at an approximately 90° angle, advantageously can be approximately 0.17in. This allows the bellows sections to be compressed significantly while easily being contained within a desired 0.25in space.

[0072] As reflected in the drawings, and particularly Fig. 26, the upper, portions 146 of the accordion sections 130, 131 are inclined slightly downward from back to front, desirably at an angle consistent with other upwardly facing surfaces of the flashing. As in the case of the vertical front portions 141 , the inclined portions 146 are comprised of foldably connected narrow panels 147, 148 extending from front to back and connected along upwardly and downwardly projected (i.e., ridge and valley) fold lines 149, 150 respectively. The cross sectional configuration of the upper accordion portions 146 corresponds closely to that of the vertical front portions 141 , with the fold lines 149, 150 having a thickness of about 0.025in compared to a thickness of about 0.085in for the panels 147, 148. Significantly, the fold lines 144 of the vertical portions 141 , forming the ridges of the front folds, are aligned with the fold lines 150 of the inclined upper portions 146, forming the valleys of the upper portions. Likewise, the ridge fold lines 149 of the inclined portions 146 are aligned with the valley fold lines 145 of the vertical portions 141 . The injection or thermoforming manufacturing process results in the junction between the upper and front portions 146, 141 forming a bevel angle of around 45°, as best indicated in Fig. 26.

[0073] Preferably, the positioning of the accordion sections 130, 131 is such that the valley fold lines 145, 150 of the vertical and inclined portions 141 , 146 are substantially in a common plane with the adjacent flat panels of the sill plate cover 123. As a result, the foldably connected panels 147, 148 of the inclined portion of the accordion always project upwardly from the plane of the adjacent inclined panels, and the foldably connected panels 142, 143 of the vertical portion of the accordion always project forwardly from the plane of the adjacent vertical panels. This allows the accordion sections to be compressed if necessary during installation without displacing the adjacent panels of the flashing, which remain properly supported by the sill plate member of the rough framing. The presence of the accordion folds

guarantees that a space will exist between the installed window unit and the underlying flashing for the drainage of water. With conventional flashings, the window unit sometimes can be mounted so tightly to the framing as to impede free outward flow of water and cause damage over time.

[0074] In the embodiment of the invention illustrated in Figs. 21 -28, the inclined upper portions 146 of the accordion sections 130, 131 are configured at the back with elevated portions 151 , best shown in Fig. 21 and Fig. 26, which are connected to the main (inclined) portions of the accordion sections by transition portions 152. The elevated back portions 151 function in combination with the elevated ridges 137-139 to provide a continuous dam or barrier to the back flow of water under the effects of high winds. The transition portions 152 are disposed at an upward angle which is greater (i.e., steeper) than that of the forward main portions, while the elevated portions 151 preferably are horizontally disposed, preferably at a slightly lower elevation than the tops of the support ribs 135, it being understood that the actual height of the elevated portions 151 will vary with the extended or compressed condition of the flashing after it has been installed in the framed opening. Inasmuch as the angles between the inclined front portions, the elevated portions 151 , and the transition portions 152 of the upper accordion portion 146 are relatively small, the ridges and valleys of the accordion fold can remain aligned. The ridge fold lines at the front remain aligned with the ridge fold lines at the back, and also the valley fold lines remain similarly aligned. This is evident in Figs. 21 and 27.

[0075] In an exemplary embodiment illustrated in Figs. 21 -28, in which the sill plate cover 123 has an as-manufactured width of about 36 inches, the front to back depth of the flashing may be about 4.7 inches, and the vertical depth of the front structure may be about 4 inches. In the 36 inch example, the two accordion sections 130, 131 each may have a length of about 10 inches. During installation of the flashing in the rough framing of a window, each of the 10 inch accordion sections can easily be expanded or

compressed by up to about 3 inches from their nominal 10 inch length.

Accordingly, a nominal 36 inch flashing according to the invention can be expanded to about 42 inches or compressed to about 30 inches, enabling a single nominal size of flashing to be installed in a wide variety of nominal sizes of rough openings.

[0076] For installation of a flashing in a rough frame opening having a width greater than the nominal width of the flashing, one end portion 121 , 122 of the flashing is first secured to an upright frame member at one side. The flashing is then extended laterally until the second end portion is engaged with the opposite side upright frame member, and the second end portion is then secured thereto. When the nominal width of the flashing is greater than the width of the rough framed opening, it is merely necessary to first compress the flashing to fit between the framing uprights and then secure each of the end portions to the upright framing members. Preferably, the flashing is secured to the framed opening by fastening the panels 126, 127 and/or 124, 125 to the vertical members 1 18 of the framed opening. Whether the flashing must be lengthened or shortened during installation, the entire installation process is highly efficient and expeditious; and since the flashing has no cuts or overlaps the weatherproof integrity of the flashing is maximized.

[0077] The flashing of Figs. 21 -28 is of significant practical benefit in that, in addition to enabling the flashing to be manufactured and installed in one piece, it further enables the manufacturers and sellers to make and inventory a smaller number of flashing sizes than the number of window sizes that can be serviced thereby. Moreover, a smaller variety of flashing sizes is required for workmen to deal with at the job site during installation, with corresponding savings in both time and money. An extra advantage resides in the fact that the ability of the accordion sections to be compressed or extended during installation also allows them to be expanded at one edge while remaining the same or being compressed at the opposite edge. For example, a vertical portion of an accordion section may be expanded fan-like in lower portions while being compressed in upper portions. The accordion sections thus have the ability to be disposed in an arcuate configuration which can be useful in connection with the flashing of curved window configurations.

[0078] Figs. 29-39 of the drawings illustrate a further embodiment of the invention which is similar in many ways to the embodiment of Figs. 20-28 but is designed to be manufactured in two or more parts, preferably injection molded. These parts are permanently joined and sealed at the factory, and delivered and installed as one piece at the job site. With reference initially to Fig. 29, there is shown a one-piece flashing 200 suitable for a window opening of about 36 inches in width. The illustrated flashing is comprised of left and right end parts, 201 , 202 which are permanently connected at a center joint 203, to be discussed further. Each end part 201 , 202 includes an end structure 204, 205 comprising a vertical front panel 206 and an inwardly facing vertical side wall panel 207 joined along its front edge with a vertical edge of the associated front panel 206, forming a right angle corner structure for mounting at the opposite lower corners of a rough-framed window opening (not shown in Figs. 29-36, but represented in Fig. 1 ). [0079] Each of the end parts 201 202 shown in Fig. 29 includes a sill plate cover portion 208, which comprises a vertical front structure 209 and a forwardly extending, downwardly inclined top structure 210. The angle of incline of the top structure 210 advantageously is about 7°

[0080] In the embodiment shown in Fig. 29, each of the parts 201 , 202 includes three accordion sections 21 1 , 212 and 213, each separated from the other by accordion connecting panels 214, 215. Outer sill cover panels 216, 217 connect the outer accordion sections 21 1 to the side wall panels 207 of the end structures 204, 205, and inner sill cover panels 218, 219 extend inward from the inner accordion sections 213, where they are permanently joined and sealed, as will be described. The accordion sections, as well as the accordion connecting panels and sill cover panels form part of the front structure 209 and top structure 210 and thus have vertical front portions and correspondingly inclined upper portions.

[0081] Referring to Figs. 30 and 31 , and comparing to Fig. 29, and assuming that the flashing of Fig. 29 has a nominal width of 36", it will be understood that a flashing of nominal width of 24" can be obtained by modifying the molds for producing the left and right flashing parts 201 , 202 to eliminate the innermost accordion section 213, and a flashing of nominal width of 18" can be obtained by modifying the molds to eliminate the accordion section 212 as well as the accordion section 213. For all three flashing sizes, the outer sill cover panels 216 are formed with a pair of upwardly projecting, wedge-shaped window support ribs 220, 221 upper surfaces of which are horizontally disposed and elevated slightly above the tops of the accordion sections 21 1 -213. In the 36" embodiment of Fig. 29, an additional window support rib 222 is provided on each of the inner sill cover panels 218, 219 to provide support under the center portion of a prefabricated window installed over the flashing. [0082] Underneath each of the window supporting ribs 220-222 is a reversely oriented wedge shaped rib 223 formed with a horizontal bottom surface (See Fig. 32). When the flashing is installed, the bottom surfaces are seated upon and supported by the sill plate of the rough framing such that the weight of the installed window is supported by the sill plate via the upper ribs 220-222 and the underlying reversely oriented ribs 223. The underlying ribs 223 also serve to support the inclined top structure 210 at the desired angle. To advantage, additional reversely oriented wedge shaped ribs 224 are provided underneath the accordion connecting panels 214, 215, and also underneath the inner sill cover panels 218', 219' of the 24" and 18"

embodiments, on which window supporting ribs 222 have been omitted. The additional reversely oriented ribs 224 serve to maintain the top structure 210 at the desired angle of incline across its full width.

[0083] As shown in Figs. 29-33, the inclined sill cover panels 216-219 and the inclined accordion connecting panels 214, 215 are provided, at a distance of approximately 4 inches from the front, with an upward step 225 of about 1 /8 ^th inch. This step functions as a dam to inhibit the rearward flow of water under extreme wind pressures. The back portions 226 (Fig. 33) of the above mentioned sill cover panels extend rearward from the step 225 for an additional approximately ¾ inch at a slight upward angle to provide an additional approximately 3/32" of elevation at the back edge of the flashing. In addition, the back portions 226 are configured to extend into contact with the sheet rock of the building. This enables caulking to be easily and effectively applied in the space between the tops of the back portions 226 and bottom surfaces of the installed window, providing a superior seal. The accordion sections 21 1 -213 are also more elevated at the back to generally follow the contours of the step 225 and the inclined back portions 226. As shown in Figs. 38 and 39, the accordion sections (represented by section 213 in Fig 39) follow the approximately 7° incline of the top structure until shortly in front of the step 225, where there is a transition section in which the accordion elements are directed at a greater upward incline through two curved portions 227, 228 followed by further upwardly inclined portions 229 which are generally parallel to the inclined back portions 226 of adjacent panels.

[0084] Details of the accordion construction are shown in the cross sectional view of Fig. 36. In the embodiment of Figs. 29-39, the accordion sections 21 1 -213 are an integral part of the injection molded sill cover end parts 201 , 202. Preferably the molded material is a thermoplastic olefin alloy, such as TPO-3985 UVP GLM Black, available from Washington Penn Plastic Co., Inc. of Washington PA, US. This material is very tough and weather resistant and is extensively used in demanding automotive applications such as bumpers. The accordion sections are comprised of a series of foldably connected narrow panels 230, which are joined along upper/outer edges by relatively thin connecting webs 231 forming ridge fold lines and along their lower/inner edges by similar connecting webs 232 forming valley fold lines. In a typical embodiment, the accordion panels 230 may have a thickness of about 0.080 inch and a width of about 0.130 inch. The ridge and valley connecting webs 231 , 231 (sometimes referred to as ridge and valley folds) may have a thickness of 0.015 inch to perhaps as much as 0.025 inch but in any case are significantly thinner than the accordion panels 230, so that flexing of the accordion elements is substantially confined to fold lines at the ridges and valleys. The ridge and valley connections may have an outside radius of about 0.037inch. In the at-rest configuration, the angle of the "V" between adjacent accordion panels 230 is about 42° and the at-rest thickness (wave height) of the accordion section is about 0.250 inch. The at-rest wave length between adjacent ridge folds 231 is about 0.354 inch. A fully compressed accordion section may have a thickness of about 0.280 inch.

[0085] As is evident if Fig. 30, for example, the vertical and inclined portions of the accordion sections 21 1 -213 are constructed so that the ridge folds 231 of the vertical portions are aligned with the valley folds 232 of the inclined portions. In the region of the intersection between the vertical and inclined portions the accordion forms a beveled face 233, seen best in Fig. 38, providing a clearance space with a window installed over the flashing. As with the embodiment of Figs. 21 -28, the accordion sections are constructed so that their valley folds 232 are substantially aligned in a plane defined by the associated sill cover panels. Accordingly the accordion panels 230 will project forwardly from the front-facing sill cover panels and upwardly from the inclined sill cover panels.

[0086] A preferred method of permanently bonding and sealing the two (or more) parts of the flashing is by a known process of linear vibration welding. In this procedure one of the parts (see right hand end part 202 in Figs. 32 and 35) is provided with a weld bead 234, which extends

continuously from a point adjacent to the back edge, along the underside of the inclined portion of the innermost panel 214, 215 or 219 (depending on the size of the assembly), and downward along the inside of the vertical portion of that panel. In the illustrated device, two parallel weld beads 234 are utilized to assure permanence of the structure and the seal. The end panel 218 of the left hand part 201 is positioned in underlapping contact with the weld beads (See Fig. 35) and the two parts 201 , 202, while the contacting surfaces are being held under pressure, are vibrated laterally until the heat of friction causes melting of the weld beads 234. The vibration is then terminated and the parts are held under pressure for a short time while the melted weld beads bond with the parts and cool. A small slot 235 is provided between the abutting edges of the two flashing parts 201 , 202 to receive lateral flash from the adjacent weld bead 234. The weld beads can be integrally molded with the end part, and in any event are of the same material as the two end parts being joined, in order to insure the integrity of the bonded joint and seal.

[0087] As will be understood by those skilled in the art, elongated flashings for particularly wide windows may be constructed by inserting one or more extension pieces (not shown) between the two end parts 201 , 202. The extension pieces, which may or may not include accordion sections, would be bonded to the end parts 201 , 202 in the same manner as is illustrated in Fig. 35 for bonding of the end parts to each other.

[0088] In Fig. 34, there is shown a modified form of the flashing for use where the rough framing is formed with 2 x 6 lumber instead of 2 x 4. For the Six inch framing, the side wall panels 207a of the end structures are extended to the rear, and the back portions 226a of the upper panels and the back portions 229a of the accordion sections are extended horizontally to the rear. Supports 223a, 224a also extend rearward from the reversely oriented ribs 223 and 224 to support the overlying extended panel portions 226a. In other respects the flashing, modified for 6 inch framing, is the same as and functions the same as the flashing designed for 4 inch framing.

[0089] To facilitate and expedite mounting of the flashing in a framing, the end structure side wall panels 207 may be provided with a V-shaped inset or recess 236, preferably extending from an upper edge of the panel 207. The V-shaped inset will help a carpenter to guide the point of a nail to the apex of the "V", where is it properly positioned for attachment of the flashing. A preformed hole may be provided to help start the nail, but preferentially the hole is omitted to provide for a better seal of the plastic material around the nail. The inset 236 may be textured so as to be readily visible to the installing carpenter.

[0090] The new variable width flashing can be used in connection with new construction and also in connection with the installation of replacement windows. For use in connection with replacement windows, the vertical portions of the sill cover, including accordion sections, are made substantially shorter, to extend downward about an inch rather than a more typical 4 inches, and the other front panels are similarly made at a width of about one- half inch. The narrower front margins are provided to accommodate previous construction features found when replacing existing windows. The functional features of the modified flashing remain the same as described above. [0091] In any of its forms illustrated and described herein, the invention represents a significant advance in the field of sill pan flashings by enabling the flashing to be shipped and installed in one piece, without requiring cutting and fitting at the job site and entirely avoiding the otherwise necessary (but only partly effective) step of performing on-site sealing of a joint between two (or more) individual parts. By providing one or more accordion sections across the width of the flashing, a one-piece flashing, as received from the factory, can be quickly installed - frequently in less than a minute - with complete assurance against leakage from improperly sealed joints and/or deterioration of the sealing materials. The flashing can be made to almost any length by combining a pair of end parts 201 , 202 with additional extension parts, with or without additional accordion sections, all fully and permanently bonded and sealed at the factory. Nothing is left to be done at the job site except to fasten the flashing in place with a couple of nails or staples.

[0092] . It should also be understood that the specific forms of the invention herein illustrated and described are intended to be representative of preferred embodiments of the invention and not in limitation thereof.

Accordingly, reference should be made to the following claims in determining the full scope of the invention.