This invention relates generally to improvements in building construction systems and methods, and more particularly to an improved metal or steel header frame for spanning a mechanical, electrical, plumbing, door or window or opening or the like in a framed building wall. More specifically, this invention relates to an improved metal jamb and header frame and related assembly adapted for use in a metal framed building wall or the like, wherein the invention facilitates rapid and structurally stable installation of a metal header stud spanning a wall opening.
In many commercial buildings, the various stud and header components used for framing a building wall comprise metal structures such as relatively lightweight or light gauge components formed from galvanized steel or the like. In this regard, a typical metal stud used for framing a building wall has an elongated, relatively thin-walled and essentially hollow construction approximating the cross sectional dimension of a conventional wood two-by-four used in traditional wood frame construction. In accordance with conventional metal frame construction techniques, such metal studs are normally connected in a vertically extending and parallel spaced-apart orientation between metal lower sole and upper header plates by means of suitable threaded fasteners such as self-tapping screws or the like, thereby facilitating relatively rapid yet structurally sturdy assembly of the wall frame components. The resultant skeletal wall frame may incorporate suitable utility lines and/or conduits, and/or insulation material prior to sheathing with finishing material such as drywall, plaster, interior/exterior paneling or siding materials and the like. These finishing products, in combination with the metal stud framing, can provide hourly fire resistance or fire retardation rates compatible with local building codes provided, of course, that Underwriter's Laboratory (UL) and local building code requirements are followed.
Modern building construction methods commonly incorporate building walls in the form of a skeletal frame structure defined by a plurality of vertically oriented studs extending in parallel spaced-apart relation between a lower or bottom runner or sole plate, and an upper track or header plate. Framed openings, particularly in heavy grade commercial construction such as hospitals and schools, are typically defined by two welded jamb studs or king studs extending vertically on opposite sides of the opening, in combination with two header studs and multiple header tracks which are field cut to length and overlapped with the adjacent vertical stud flanges at appropriate elevations to insure a positive connection between building components.
As a result of this added build-up, two problems are presented. The first is that the hourly fire code rating of the opening and adjacent wall structure is affected by the inability of the finishing product to rest flush against the metal stud framing. For example, at a rated door opening the drywall is required to nest to the inside of the door frame, but due to the build-up of overlapping components at the inside corner connection points, typically (but in violation of building codes) the door frame is altered by bending tabs on the metal frame components or drywall finishing material is back-cut to accommodate the unforeseen added dimensions. Both of these alteration techniques void the requisite hourly fire code ratings for the opening. The second problem pertains to build-up of material at the connecting corners of the header studs/tracks to the jamb studs, wherein this build-up results in unsightly bulges and cracks in the finishing material thereby decreasing the quality of the finished wall. Significant time, material and labor is required to correct these problems.
In the past, multiple metal header studs and tracks spanning the top and bottom of a framed door, window or other mechanical opening, and a pair of metal jamb or king studs on opposite sides of the opening, have commonly been connected together and to the associated jamb studs by welding. Also, prior to the present invention, a metal framed stud building requiring a “chase” wall or two walls parallel to each other to accommodate mechanical and plumbing lines and the like, and further incorporating a framed opening for a door or window or mechanical duct or the like, could only be framed with the use of added stud gusset plates, straps and brackets due to the inability to weld inside or interior points of attachment. The use of these added parts and the requisite installation labor has been directly due to the inability to make connections to, through and around such adjacent parallel walls.
Unfortunately, such welding steps require the use of specialized and typically certified welding personnel, expensive welding equipment, and associated specialty inspectors to inspect and approve completed welds. Moreover, each weld represents a relatively time-consuming task that must be performed with considerable precision and care. As a result, in a heavy duty commercial metal framed construction project such as a hospital or school having numerous mechanical, electrical, plumbing, medical gas, door and/or window openings each presenting a fire-life-safety concern, the cost associated with jamb and header metal stud framing can be substantial.
Another problem that exists in the conventional or commonly used method of framing such mechanical openings is the inability to a dust or rework an opening due to a variety of occurrences in commercial framing. For example, changes made by the architect or owner, out-of-level concrete floors, and out-of-square framed openings all require adjustment and reworking of the opening. Current assembly methods require complete or substantially complete dismantling of the opening-forming structure, without the ability to level or square framing components.
There exists, therefore, a significant need for improvements in and to metal frame construction systems and methods, wherein metal jamb and header studs spanning building openings can be installed quickly and easily and in a structurally sturdy and stable manner, to provide a finished product of high quality and reduced construction cost, without requiring welding or the time and labor costs associated therewith, and further without jeopardizing or comprising fire code ratings. The present invention fulfills these needs and provides further related advantages.