Patent Application
20050144865
This invention relates generally to window and door installations and more particularly to sill pans installable beneath window and door units to prevent water migration into underlying framing and sub-flooring.
In modern construction, window and door systems generally are provided as integral pre-hung units that include door or window panels pre-mounted in a frame. The frame typically is formed by vertical jambs, a top header, and a bottom sill or threshold assembly that spans the bottom ends of the jambs. These pre-hung units are fitted and secured within appropriately sized framed-in openings in the walls of a building. In the case of windows, the openings generally are framed by a horizontal bottom sill plate, vertical studs, and a header. Framed-in openings for pre-hung door units also include vertical studs and a header, but the bottom sill plate of the door opening usually is formed by the sub-floor of the building. In either event, the pre-hung unit is positioned with its sill or threshold resting on the bottom sill plate of the framed-in opening, whereupon the unit is leveled, plumed, and secured within the opening with nails or screws.
An age-old problem with window and door units is the tendency, over time, for rain water to leak beneath the sill or threshold of the unit. Such leakage often occurs at the lower corners of the unit where the jambs meet the sill, but also can occur in mid-portions of the unit as a result of cracking or separation of sill components. Eventually, this leakage causes the underlying framing studs and sub-floor components to rot. Since this rot generally is hidden from view, it often is not discovered until it is so severe that major renovation to replace rotted members is required.
To address the problem of rain water leakage around windows and doors, building products suppliers have developed water-proof sill pans. These sill pans generally are designed to be installed in a framed-in window or door opening extending along and covering the bottom sill plate of the opening. Most prior art sill pans are made of plastic and include a central web that rests on and spans the plate, upwardly projecting end walls that extend partially up the vertical studs of a framed-in opening, an up-turned flange extending along the inside edge of the web, and flashing strips that wrap around onto the outside of the framed-in opening. In some cases, flashing pans are integrally molded from a single piece of plastic. In others, end pieces of molded plastic are installed in the bottom corners of a framed-in opening and a separate elongated central web is installed along the bottom plate with its ends partially overlapping the end pieces. The overlapping ends of the web are then secured to the end pieces with, for example, PVC cement or other adhesive. In any event, the purpose of a sill pan is to intercept rain water that may leak beneath a window or door unit and to prevent that water from soaking into wooden framing members and sub-floor components, thereby to prevent the rotting of these structures. Examples of prior art sill pans can be found in U.S. patents including U.S. Pat. No. 6,089,343 of Brown, and U.S. Pat. No. 6,401,402 of Williams. Prior art sill pans of the types discussed above are available from a number of building products suppliers, including Dinesol Building Products Ltd. of Youngstown, Ohio and Jambsil, Inc. of Talent, Oreg.
While prior art sill pans have been somewhat successful, they nevertheless have been plagued with a variety of problems and shortcomings inherent in their respective designs. Single piece molded sill pans, for instance, rarely fit precisely between the vertical jambs of a framed-in opening. This results in gaps between the ends of the sill pan and the jambs or in creases in the plastic of the pan, which can allow rainwater to seep beneath the sill pan and into the framing members below. Multiple piece sill pans result in a good fit between the jambs, but suffer from poor adhesive coverage and thus poor seals between the ends of the center web and the end pieces, which they overlap. Poor seals can result, in part, from the requirement in some systems that the overlapping portions be held together for 5 or more minutes as the adhesive sets. Installers are unlikely to follow these instructions, resulting in poor and leaky adhesive joints and thus poor seals. These poor seals allow water to seep through the adhesive joints and into the framing members below. Further, in both of these sill pan designs, water that is intercepted by the sill pan can collect between the sill pan and the wooden sill of windows, which can result in rotting of the window sill itself.
Another problem with prior art sill pans, especially when installed beneath door units, is that the constant jostling of the threshold of the door unit as it is repeatedly stepped on during use can wear through the material of the pan at locations where the door unit rests on the pan. This is particularly true for metal door units. At least one manufacturer has attempted to address this problem by providing an aluminum cladding bonded to the surfaces of the sill pan in areas of door unit contact. This solution, however, is expensive, not always successful, and can result in an unpleasant clicking sound when stepping upon the threshold.
A continuing need exists for an improved sill pan system that successfully addresses the above and other problems and shortcomings of existing prior art seal pans. It is to the provision of such a sill pan system that the present invention is primarily directed.
Briefly described, the present invention comprises a sill pan system that successfully addresses the problems and shortcomings of the prior art. In one embodiment, the system comprises molded plastic end pieces that are fitted in the bottom corners of a framed-in door or window opening. The end pieces are formed with a flat panel, upstanding end walls that extend partially up the vertical studs of the opening, an upturned inside flange, and flashing that overlaps the outside of the framing members in the corners of the opening. A central web is configured to be installed between a pair of pre-fitted end pieces with the ends of the central web partially overlapping the end pieces. The central web has an upturned inside flange sized to match and form extensions of the inside flanges of the end pieces. The central web also has a downturned flashing strip along its outside edge, which is sized to match and form extensions of the flashing of the end pieces. Thus, when the central web and end pieces are in place in a framed-in opening, they form a sill pan that spans and covers the bottom sill plate of the opening in a somewhat traditional way.
In one embodiment of the sill pan system of this invention, the overlapping ends of the central web are bonded to the end pieces with an adhesive sealant such as, for instance, an adhesive caulk. According to one aspect of the invention, the central web of the sill pan system is made of a clear, translucent, or otherwise non-opaque extruded plastic material, at least in regions of overlap with the end pieces. Thus, when the overlapping ends of the central web are pressed onto the end pieces with adhesive sealant sandwiched therebetween, the spreading pool of sealant is clearly visible to the installer through the translucent material of the web. It has been found that any breaks, discontinuities, or regions of poor coverage in the pool of adhesive sealant become starkly apparent as the pool is viewed through the ends of the central web. Thus, a quick visible inspection by the installer after installation of the central web is all that is required to confirm that a complete water-tight seal has been formed between the end pieces and the overlapping ends of the central web. Alternatively, if a poor seal is indicated upon such visible inspection, the installer knows that leaks may occur and can repair the seal or simply remove the pan and replace it with a fresh pan with a visually confirmed seal.
In another aspect of the invention, the end pieces and central web of the pan system may be formed with a multi-ply plastic construction, especially for doorway installations. The upper surfaces of these components may be a cladding of hard abrasion resistant plastic such as, for example, polyurethane or nylon, and with the underlying substrate being made of a far less expensive plastic such as PVC. It has been found that sill pan components with such abrasion resistant upper surfaces can be even more resistant to being worn through by door units resting thereon than prior art aluminum clad sill pans. Further, the co-extrusion or co-molding of multi-ply plastic components is far less expensive and troublesome that fabricating plastic components with metal clad surfaces, as has been attempted in the prior art. The result is a superior abrasion resistant sill pan and lower manufacturing costs.
In yet another aspect of the invention, the upturned inside flange of the central web is formed to define a slot that receives and holds securely the upturned flanges on the end pieces when the ends of the web are overlapped and pressed onto the end pieces. In this way, the overlapping ends of the web are held automatically to the end pieces, eliminating the requirement that the components be held together for long periods of time while the adhesive sets. An installer need only press the ends of the web onto the end pieces, where they are held in place by the slots.
A further aspect of the invention includes longitudinal drainage channels formed along the length of the central web. These channels may be formed, for example, by short upstanding ribs or by longitudinal deformations in the web. In either event, water that may collect between the pan and overlying sill is directed along the channels to the ends of the drain pan, where it is more free to drain away.
In another aspect of the sill pan system of this invention, the central web is extruded as a very long single piece. The upstanding flange along the inside edge of the web and the flashing strip along its outside edge are connected to the central portion of the web by flexible hinge joints. These hinge joints may be a co-extrusion of a flexible plastic material or may be formed by extruded score lines in the web. With such a construction, it has been found that the long single piece of web material can be rolled up into a roll with the flange and flashing strip co-extensive with the central portion of the web. For installation of a sill pan, a length of web material is extracted from the roll and cut to the precise length needed to span and partially overlap the end pieces. The inside flange and flashing strip are then simply bent respectively up and down and the central web is installed as described above. With this unique construction, multiple sill pan installations can be shipped to installers in the form of several end pieces and a roll of web material, which is more efficient, less expensive, and produces less waste than traditional sill pan systems.
Thus, a unique sill pan system is now provided that successfully addresses the problems of prior art sill pans and their installation and that offers new advantages heretofore not available at all. These and other features, objects, and advantages of this invention will become more apparent upon review of the detailed description set forth below taken in conjunction with the accompanying drawing figures, which are briefly described as follows.
Referring now in more detail to the drawing figures, wherein like numerals refer, where appropriate, to like part throughout the several views,
The sill pan system 11 includes a right end piece 16 fitted in the bottom right corner of the framed-in opening and a left end piece 17, which is a mirror image of the right end piece, fitted in the bottom left corner of the framed-in opening. Preferably, each of the end pieces unitarily is fabricated of molded plastic material, as described in more detail below, and is impervious to water. The right end piece 16 is configured with a top panel 18, which overlies and covers a relatively short section of the sill plate 13, and a vertical end wall 19, which extends partially up the inside face of the vertical stud 14. An inside flange 21 projects upwardly along the inside edge of the panel 18 and flashing 22 overlaps the outside surfaces of the vertical stud 14 and the sill plate 13. The right end piece 16 terminates in a free end portion 23 spaced a relatively short distance from the vertical stud 14. It will thus be appreciated that the right end piece covers and protects the right end of the sill plate 13 and the bottom right corner portion of the framed-in opening 12.
Similarly, the bottom left corner of the framed-in opening is covered and protected by the left end piece 17, which, like the right end piece, has a top panel 26, a vertical end wall 27, an upwardly projecting inside flange 28, flashing 29, and a free end portion 31. Like the right end piece, the left end piece 17 covers and protects the left end of the sill plate 13 and the bottom left corner portion of the framed-in opening.
An elongated central web 36, which preferably is fabricated of extruded plastic material, is fitted on the sill plate 13 extending between the right and left end pieces 16 and 17. The length of the central web 36 is selected so that the ends of the central web overlap the free end portions 23 and 31 of the right and left end pieces respectively. The central web 36 is formed with a panel 37, an upstanding interior flange 38 extending along the inside edge of the panel 37, and a downturned flashing strip 39 extending along the outside edge of the panel. It will be seen from
According to one important aspect of the present invention, the central web 36 is made of extruded plastic material such as, for instance, PVC. Further, the plastic material of the central web is formulated to be transparent, translucent, or otherwise non-opaque. This provides a unique advantage over prior art sill pan systems. Specifically, since the central web is non-opaque, the adhesive sealant 46 and 47 is visible to an installer through the central web as the central web is installed in the opening. As the ends of the central web are pressed down onto the overlapped free ends 23 and 31 of the end pieces with adhesive sealant between them, the spreading pool of sealant can be observed through the central web. If a void develops or is present in the pool of sealant during this process, the void is clearly visible to the installer and the installer is instantly aware that the void could result in water leakage. The installer can then take remedial action, such as applying additional sealant or simply removing the sill pan and installing a new pan. More typically, the installer will observe that the pool of sealant is smooth, continuous, and voidless, which confirms that a good seal has been formed and that water leakage between the overlapping portions of the central web and end pieces will not occur.
The abrasion resistant cladding provides a durable surface upon which portions of a door or window unit may rest. This aspect of the invention is particularly suitable for use beneath door units, which tend to move slightly and grind around on the sill pan as the threshold is stepped upon during use. Such action can, over time, wear through a sill pan made only of softer base material such as PVC, resulting in water leakage to the subfloor. However, the abrasion resistant cladding of the present invention provides a surface that is as highly resistant to wear, and, in fact, even more resistant than sill pans with metal clad exposed surfaces, which have been offered in the past. Advantageously, the process of forming sill pan components in a single co-molding or co-extrusion process is far less expensive and time consuming that the fabrication techniques required to provide metal clad sill pan components.
The central web 36, which preferably is formed of extruded plastic, has an elongated top panel 37, an inside flange 38 extending along the inside edge of the panel, and a flashing strip 39 extending along the outside edge of the panel. The central web may or may not be formed with an abrasion resistant cladding as desired. The inside flange 38 in this embodiment is formed with an additional feature according to the invention. Specifically, a downturned leg 51 is formed with and spaced from the inside flange 28 to define a downwardly facing slot 52. The slot 52 is sized and configured to receive and capture a length of the inside flange 21 of the end piece when the central web is moved down into position as indicated by arrows 57. In this way, when an installer presses the ends of the central web down into the pool of adhesive sealant 46, the inside flange 21 of the end piece is securely captured and held in the slot 51 until the adhesive cures. This eliminates the requirement of prior art systems that the overlapping ends be held manually together by an installer for several minutes until the adhesive sealant cures, which installers, in reality, are not apt to do.
The central web 36 in
In the embodiment illustrated in
While the central web stock 61 in
Finally, the central web stock is the preferred embodiment is formed with a flange and flashing strip made of a hard plastic that are attached to the panel 63 with flexible hinges, the invention also contemplates that the flange and or flashing strip may be formed completely of a softer flexible plastic extending laterally from the edges of the panel 63. With such a configuration, the web stock is also rollable and the flexible flange and flashing strips can be bent into the proper configuration during the installation process.
The invention has been described herein in terms of preferred embodiments and methodologies. It will be understood by those of skill in the art, however, that a wide variety of additions, deletions, and modifications may well be made to the preferred embodiments illustrated herein without departing from the spirit and scope of the invention. For instance, in the preferred embodiments, the central web is installed after the end pieces are fitted and the ends of the central web partially overlap the end pieces. Thus, it is the central web that is non-opaque in the preferred embodiments to permit visual inspection of the pool of adhesive sealant between the overlapping sections. An equivalent construction, however, could entail the installation first of a central web and then the fitting of end pieces that partially overlie the ends of the central web. In such an equivalent system, it would, of course, be the end pieces that are transparent, translucent, or otherwise non-opaque to allow visual inspection of the pool of adhesive sealant between the overlapping portions of the web and end pieces. Accordingly, the preferred embodiments presented herein are intended only as that, and as illustrating the best mode known to the inventors of carrying out the various aspects of the inventions disclosed herein. The scope of the invention embodied in the illustrated embodiments is limited only by the claims presented below.
