EXTENDED SHORT SPAN TEE FOR DRYWALL CEILING
A short span flat drywall ceiling construction comprising a pair of spaced parallel wall angles facing one another, the wall angles each having a vertical leg secured to vertical support surfaces and a horizontal leg cantilevered from its respective vertical leg towards the other wall angle, a plurality of substantially identical roll-formed sheet metal tees extending between the wall angles and vertically supported thereby, each tee having a main body formed of a single strip of sheet steel, the tee having a horizontal single layer lower flange, a vertical double layer central web disposed above the flange, and a bulb at the top of the web centered on a plane of symmetry, a sheet metal U-shaped reinforcement channel fitted on a central part of the length of the tee such that it is in contact with at least the sidewalls of the bulb.
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The invention relates to building construction and, in particular, to short span flat drywall ceiling construction.
PRIOR ARTA type of ceiling construction found in commercial buildings involves the use of horizontally spaced inverted metal tees suspended by wires from overlying structure. Sheets of drywall are fastened by screws to these metal tees and then are taped and otherwise finished. Building areas such as corridors, stairwells, landings, and small rooms found in apartments, condominiums, hotels, motels, dormitories, and the like are commonly finished with flat drywall ceilings. These building areas are typically relatively narrow and, therefore, involve a relatively short span from wall-to-wall. In many instances, the space or plenum above the ceiling, especially in corridors and hallways, is occupied by duct work, conduit, and mechanical equipment. The presence of this and like equipment frequently interferes with the installation of suspension wires. As a result, additional layout planning, tradesmen scheduling and, eventually, more labor, is incurred. Frequently, unforeseen physical interference problems add to the cost of construction.
SUMMARY OF THE INVENTIONThe invention involves an improved tee construction that can advantageously be used for supporting flat drywall ceilings in extended “short span” applications. The disclosed tee construction is capable of supporting standard drywall sheets and satisfying applicable building codes while avoiding the need for suspension wires. The tees of the invention are sufficiently rigid to enable them to be supported exclusively at their ends on conventional wall angles. This rigidity avoids the labor of anchoring overhead suspension wires and the problems associated with interference with equipment in the space above the ceiling. The disclosed tees are commercially made with mostly existing technology, tooling, and material stock. Only a limited quantity of extra material is used in the manufacture of the disclosed tee forms of the invention.
More specifically, standard drywall tees are effectively rigidified by increasing their section modulus with a channel sized to closely fit with the standard reinforcing bulb provided at the top of the inverted standard drywall tee form. The resulting tee, in accordance with the invention, is familiar in form and size. The relatively low profile or height of the inventive tee affords full utilization of the space above the ceiling for free placement of utilities, duct work and like equipment without the need to leave clearance for suspension wires or to improvise and fabricate custom anchor points for the suspension wires. The freedom to use the full space of the plenum and not be hindered by suspension wires or supplemental brackets or supports is an important feature. This freedom is in addition to the basic cost savings obtained by eliminating the need for locating, installing, and tying off suspension wires.
The disclosed tee construction of the invention retains the benefit of a relatively light gauge tee body material and a single wall flange thereby affording easy and reliable penetration by self-drilling drywall screws.
The opposed walls 12 can be of any suitable construction. In reference to
The ceiling structure 11 comprises a wall angle 18 on each of the opposed walls 12, support tees 14 extending between the wall angles, and drywall sheets 13 screwed to the lower sides of the tees. The wall angles 18 are conventional elements preferably formed from knurled or dimpled sheet metal strips and are nominally 1″ high by 1½″ wide or metric equivalents, and of, for example, a nominal gauge of 0.020 inch thickness. The wall angles 18, typically, are secured to the walls 12 with self-drilling drywall screws 21 driven through the drywall sheets 17 into the studs 16.
A roll-formed sheet steel inverted channel 41 is closely fitted and assembled in the interior of the bulb 36. The material of the channel 41 can be slightly heavier in gauge than the tee main body 27. For example, the stock forming the channel 41 can be a nominal minimum of 0.024″ thick. Ideally, a bight 42 of the channel 41 abuts the upper wall of the bulb 36. The channel 41 ordinarily will run from end-to-end of the tee main body 27. The channel 41 can be locked in the illustrated position by appropriately punching or piercing the sidewalls, designated 43 of the bulb 36 at spaced locations along the length of the main tee body 27.
While the invention has been shown and described with respect to particular embodiments thereof, this is for the purpose of illustration rather than limitation, and other variations and modifications of the specific embodiments herein shown and described will be apparent to those skilled in the art all within the intended spirit and scope of the invention. Accordingly, the patent is not to be limited in scope and effect to the specific embodiments herein shown and described nor in any other way that is inconsistent with the extent to which the progress in the art has been advanced by the invention.
Claims
1. A short span flat drywall ceiling construction comprising a pair of spaced parallel wall angles facing one another, the wall angles each having a vertical leg secured to vertical support surfaces and a horizontal leg cantilevered from its respective vertical leg towards the other wall angle, a plurality of substantially identical roll-formed sheet metal tees extending between the wall angles and vertically supported thereby, each tee having a main body formed of a single strip of sheet steel, the tee having a horizontal single layer lower flange, a vertical double layer central web disposed above the flange, and a bulb at the top of the web centered on a plane of symmetry, the bulb having a pair of opposed generally vertical walls each spaced from the plane of symmetry, a top bridging a space between the vertical walls and a bottom that merges with the double layer of the web, a sheet of drywall secured against lower faces of the tees with screws driven through the drywall into the flanges of the tees, a sheet metal U-shaped reinforcing channel fitted on a central part of the length of the tee such that it is in contact with at least the sidewalls of the bulb, the nominal height of the main body of the tees being between about 1½″ to about 1⅝″, the length of the tees being between preferably about 7′ to preferably between about 8½′ to about 9′ long.
2. A ceiling construction as set forth in claim 1, wherein the reinforcing channel is on the inside of the bulb and runs the full length of the tee.
3. A ceiling construction as set forth in claim 1, wherein said reinforcing channel is fixed to the outside of the bulb.
4. A ceiling construction as set forth in claim 3, wherein said channel has a central rib extending above the bulb.
5. A ceiling construction as set forth in claim 4, wherein the bulb has a vertical height, the central web of the reinforcing channel extends above the bulb a distance at least half the height of the bulb.
6. A ceiling construction as set forth in claim 1, wherein the tees are spaced from one another a nominal distance of 16″ or 24″ or metric equivalent.
7. An extended short span tee for constructing flat drywall ceilings, the tee being roll-formed from two strips of steel sheet and being symmetrical about a central vertical plane, a first of said strips forming a single layer horizontal lower flange, a double wall central vertical web and a hollow upper reinforcing bulb, the reinforcing bulb being generally rectangular in cross-section with generally vertical sidewalls, the second strip being formed into an inverted U-shaped channel with a pair of vertical sidewalls and a horizontal web, the channel sidewalls being proportioned to abut the sidewalls of the reinforcing bulb, the first strip of the tee having a length of between about 7′ and about 9′ or metric equivalent.
Type: Application
Filed: Apr 9, 2009
Publication Date: Oct 14, 2010
Applicant: USG INTERIORS, INC. (Chicago, IL)
Inventors: Muhammad Raheel (Mundelein, IL), Peder Gulbrandsen (Aurora, IL), James J. Lehane (McHenry, IL)
Application Number: 12/420,902
International Classification: E04B 9/22 (20060101);