Patent Application
20060059798
This invention generally relates to a wooden casing, such as a door frame or window frame, that prevents wood rot when installed on a horizontal base, such as a concrete slab, where the base may be comprised of a porous material or subjected to moisture accumulation. The invention prevents the communication of moisture from the base to the casing because the casing is spaced above the base a distance exceeding the meniscus of water. The invention specifically relates to a design for a rot resistant wooden window or door frame. The invention also relates to a method of making a rot resistant casing.
Many wooden door and window frames provide no protection for the wooden surfaces that abut a floor or base. Consequently moisture may be “wicked up” from (or through) the floor or similar horizontal surface and into the associated wooden structure. Doorjamb end grains have proven to be particularly problematic because of their affinity for absorbing moisture. Should the moisture in the wood achieve a sufficiently high level, then the wood may eventually rot. Wood rot typically cannot be repaired in situ, thus necessitating the replacement of the door or window frame.
Several techniques and systems have been used address the problem associated with wood rot in door frames and other similar structures. One such system involves splicing a rot resistant material, such as plastic or plastic composite, with a wooden frame member to create a wooden door frame having a finger-joint connecting the wood and plastic components together. This method is relatively expensive and the spliced portion of the door frame may not accept paint or finish in the same manner as a wooden door frame, and consequently the finished door frame does not have a uniform finish and appearance.
The prior art also includes the use of an insulating strip across the door frame end grain, as shown in U.S. Pat. No. 6,161,343 to Young, entitled Wood Rot Preventing Wood Casing End Grain Moisture Barrier Assembly and Method, the inventor of which is also the inventor hereof. While this method is effective, it requires relatively precise placement of the insulating strip. Additionally, the applicant has found that most wood rot can be prevented by securing the frame to a sill in order to space the door frame or exposed end grain wood surface a distance from the floor or base that is greater than the meniscus of water. Precisely spacing a door frame relative to a sill in a large-scale production process is difficult and cost prohibitive.
The need exists for an effective and efficient assembly that is inexpensive to manufacture and effectively prevents wood rot. The disclosed invention provides an end grain assembly that incorporates at least two button-type components to precisely space a wooden casing such as door frame, window frame, brick mold or the like, above a horizontal surface and thereby prevent moisture from “wicking up” into the associated wooden casing. The “buttons” require less material and a less sophisticated manufacturing process than the prior art rot prevention methods, while still effectively preventing wood rot.
The present invention is an assembly comprising a vertical wooden member with at least two buttons attached to the lower exposed end grain of the vertical member. The vertical member is attached to a sill assembly, which extends perpendicular to the vertical member. The sill assembly has a lower planar surface that defines a horizontal plane. The buttons elevate the vertical member above the horizontal plane defined by the planar lower surface of the sill assembly.
The present invention also comprises a door frame assembly that includes a vertically extending wooden door frame that is spaced above an essentially horizontal floor by two cylindrical buttons. The top of each button is attached to a doorjamb exposed end grain, and the bottom of each button abuts the floor. A doorsill assembly is secured to the doorjamb and extends normal to the doorjamb. The buttons elevate the doorjamb end grain above the floor and thereby prevent wood rot in the doorjamb.
The present invention also comprises a method of making a rot resistant assembly. The method comprises providing a vertical wooden member that has an end grain face. At least two buttons are attached to the end grain face. A frame assembly is created by connecting a sill assembly to the vertical member so that the bottom of the sill assembly is disposed in the same horizontal plane as the bottom of the buttons. The frame assembly is then installed on a horizontal surface so that the vertical member is elevated above the horizontal surface to a height greater than the meniscus of water, thereby preventing water from being drawn up from the horizontal surface and rotting the vertical member.
The present invention comprises a rot resistant casing 10, primarily designed for door and window frames. Specifically, the invention comprises a casing 10 that prevents communication of moisture from a floor or horizontal base upwardly into a wooden window or doorjamb 12. Although the rot-resistant casing shown in the drawings and described in the specification is generally applicable to a door frame, the invention also has application in other types of structures, and the scope of the invention is not limited to doors or windows.
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A method of making a rot-resistant assembly is also within the scope of the invention. The casing 10 is constructed by attaching at least two buttons 14 to the end grain portion 16 of a doorjamb 12. The casing 10 is connected to a doorsill 18 so that the bottom faces 23 of the buttons 14 are disposed on the same horizontal plane as the planar lower surface 19 of the doorsill 18, thereby creating a door frame assembly. The door frame assembly is installed on a horizontal surface so that the doorjamb 12 is elevated above the horizontal surface 19 to a height exceeding the meniscus of water, thereby preventing water from being drawn up from the horizontal surface and subsequently rotting the doorjamb 12. As best shown in
For the foregoing reasons, it is clear that the present invention provides a rot-resistant assembly that addresses the problem of moisture migration from a horizontal base to an adjacent wooden member. The method and apparatus described above is effective as well as relatively inexpensive to construct.
The invention may be modified in multiple ways and applied in various technological applications. For example, the invention may be used with a garage door frame or in applications that do not include a doorsill 18. Although the materials of construction are described, they may include a variety of alternative compositions consistent with the function of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
