Patent Application
20060053721
The present invention relates generally to the field of building construction and more particularly to a coated ceiling structure for the interior of a building and a method of forming the same.
Industrial facilities and other buildings are often exposed to air that is laden with corrosive and otherwise harmful chemicals in the form of liquids, vapors, gases and solid particulate matter. The presence of such airborne contaminants, as well as extreme temperatures and humidity, can lead to the premature wear and eventual failure ofbuilding materials, including interior ceiling structures, made from materials such as steel, wood, concrete and masonry. Many factors contribute to the deterioration of such building materials, including chemical corrosion, water absorption, condensation, mold development, loss of strength, loss of thermal insulation efficiency and the like.
Suspended or “drop” ceiling installations are well known in the building construction field. Suspended ceiling systems typically comprise a rigid grid or frame suspended from or attached to the interior surface of a roofing structure or the bottom side of a floor structure within a building. Rigid panels or tiles are then individually inserted into the openings in the grid. Each panel is supported on a ledge that extends around the perimeter of the respective opening of the grid.
Suspended ceiling panels can be made of a wide variety of materials and serve numerous purposes such as providing thermal insulation and sound absorption and improving aesthetics. Moreover, by lowering the level of the ceiling within a building, suspended ceilings effectively reduce the air volume within the building that must be heated, cooled or filtered, thereby reducing equipment costs and energy consumption. A suspended ceiling may also offer protection to building materials and structures attached to the ceiling, such as air handling and electrical equipment. However, conventional suspended ceiling systems are not capable of withstanding long term exposure to the harsh environments that exist in many commercial and industrial buildings, such as described above, without degradation and eventual failure.
According to the present invention, a method of forming a coated ceiling structure comprises the steps of: providing a base ceiling structure having an outer surface; applying a foam material in a fluid state to the outer surface of the base ceiling structure; and solidifying the foam material to form a rigid reinforcing layer on the base ceiling structure.
According to a further aspect of the present invention, a method of forming a ceiling structure comprises the steps of: providing a base ceiling structure comprising a non-self-supporting material; and spraying a reinforcing material onto an outer surface of the base ceiling structure. The reinforcing material and the non-self-supporting material together form a self-supporting composite structure.
According to a still further aspect of the present invention, A ceiling system comprises: a base ceiling structure for suspending from a structural member of a building; a substrate attached to the base ceiling structure; and a sprayable reinforcing material adhered to the substrate. The sprayable reinforcing material and the substrate together form a self-supporting composite material.
As shown by way of example in
The frame members 14 and connecting members 16 of the grid structure 10 may be made from any suitable material(s), including solid and cellular plastics, other polymers, steel, aluminum, wood, composite materials and the like. The cross-sectional dimensions of the frame members 14 and connecting members 16 are selected in accordance with strength and other requirements of a particular application. The wires 12 that suspend the grid structure 10 from the building structure may be made of any suitable material and are selected to have an appropriate strength, thickness and spacing between wires, depending upon factors such as load, regulatory requirements and other applicable requirements for a particular application.
As best shown in
According to a first example embodiment of the present invention, as shown in
By applying the foam material 26 and/or the outer coating 28, according to the present invention, it may be possible to use materials for constructing a suspended ceiling structure that would not by themselves meet strength and other engineering and/or regulatory requirements. For example, certain geographic areas, such as California, have state-mandated strength requirements for resisting seismic activity. In this example, less expensive materials that do not meet the seismic requirements could be used to construct a suspended ceiling structure, which would then be sufficiently reinforced according to the present invention to meet the seismic requirements. Other examples of regulatory requirements include national standards promulgated by the American Society for Testing Materials (ASTM), such as ASTM C 635, ASTM C 636, ASTM E 580, ASTM E 1264, which are incorporated by reference herein.
In the first example embodiment of
Polyurethane foam is particularly suitable for spraying onto a ceiling structure according to the present invention, since it is capable of being sprayed as a foam. Once set, polyurethane foam produces a layer or membrane having a relatively high strength to weight ratio and a relatively high insulation value. However, other materials, such as intumescent paints or coatings, having suitable properties may be used according to the present invention in place of, or in addition to, polyurethane foam.
Further, the foam material 26 can vary in formulation to produce a variety of achievements. For example, the density of the foam material 26 can be varied to adjust a reaction time of the material. The term “reaction time” as used herein refers to the average amount of time it takes for a sprayed material to form a cellular foam once it is sprayed or otherwise applied to the base ceiling structure 25. By adjusting the amount of certain chemical additives in a polyurethane material, for example, the density of the resulting foam material 26 can be adjusted within a range, typically from 0.5 lb/ft3 to 3 lb/ft3 having a reaction time typically between one second and one minute, more or less. The density and reaction time of a particular material affects certain physical properties of the resulting foam material, including weight and strength.
Additionally, the contact pressure of the foam material 26 as it is sprayed onto the base ceiling structure 25 may be varied as necessary to produce a sufficiently strong and lightweight layer or membrane of foam material that solidifies or sets quickly enough. For example, the contact pressure of the foam material must be properly set to prevent the weight of the material to cause it to deform too greatly or even fall off of the base ceiling structure 25 before it can set. Contact pressure can be adjusted, as is known in the art, by varying such factors as the formula of the material, the particular equipment used to spray the material, and pressure and other settings of the spraying equipment.
The seamless nature of the spray-applied layers of the present invention, such as the foam material 26 and/or outer coating 28, provides a monolithic, aesthetically pleasing and protective membrane that protects the underlying base ceiling structure 25 from moisture, chemicals, heat, fire and/or other environmental conditions detrimental to their long term performance and use in many applications. Moreover, the spray-applied materials can add substantial strength and rigidity to the base ceiling structure 25 enabling thinner, less strong and less costly grids, panels and non self-supporting materials to be used.
In the following example embodiments of the present invention shown in
According to a second example embodiment of the present invention,
The non-self-supporting material 32 can be attached to the underside of the grid structure 10 by mechanical fasteners 34, such as nails, screws, bolts, brads, staples, rivets or other suitable fasteners. A continuous sheet of the non-self-supporting material 32 can be used to cover the underside of an entire grid structure 10. In this embodiment, the grid 10 and the non-self-supporting material 32 forms a base ceiling structure 25′ onto which the foam material 26 and/or other layers is applied in accordance with the present invention. Alternatively, panel-like sections (not shown) of the non-self-supporting material 32 can be used, each section covering one or more of the openings 18 in the grid structure 10. Seams between the sections of non-self-supporting material 32 are not apparent since, once the foam material 26 is applied, a seamless composite ceiling structure 33 is formed. Suitable non-self-supporting materials 32 include, for example, single or multiple layers of various materials such as heat shrinkable or non-heat shrinkable plastic films and sheets, open mesh and tightly knit fabrics, felt, wire mesh, and the like. Alternatively, the self-supporting materials described with reference to the first example embodiment and shown in
A third example embodiment of the present invention, as shown in
Although the specific example embodiments of the present invention that are described herein are directed to materials that are sprayed onto a base ceiling structure 25, other suitable techniques can be used to apply the foam material 26 or other materials used to coat the underside of the base ceiling structure 25. For example, the foam material 26 or other suitable coating material could be applied on the underside of the base ceiling structure 25 by pumping or otherwise extruding the foam material 26 from a suitable nozzle or applicator so that it flows directly onto the base ceiling structure 25. Other possible methods of applying the coating material include rolling, brushing, troweling, sponging, hand rubbing/packing, air spraying, airless spraying, and other known techniques for applying coating materials.
Further, although the specific example embodiments of the present invention that are described herein are directed to applying coating materials to a suspended base ceiling structure 25 comprising a grid structure 10, the present invention contemplates the application of coating materials to other ceiling structures, including grid-less and/or non-suspended ceiling structures. As used herein, the term “non-suspended” refers to ceiling structures that are directly and/or rigidly attached to a building structure or underlying ceiling structure of a building, such that there is little or no space or gap therebetween. Further, as also used herein, the term “grid-less” refers to ceiling structures that do not include a separate supporting grid or frame to support the material to which the inventive coating(s) is/are applied. One example of a grid-less ceiling structure, not illustrated herein, comprises a plurality of interlocking tiles being suspended from or attached directly to a building structure. Another example of a grid-less ceiling structure, not illustrated herein, is a web of non-self-supporting material that is suspended under tension from surrounding wall structures. Other suitable materials and structures may be used according to the present invention.
The suspended base ceiling structure 25 described in the disclosed example embodiments are shown and described as being suspended from a building structure by a plurality of wires 12. However, other structures for suspending a base ceiling structure 25, in place of the plurality of wires 12, are contemplated to be within the scope of the present invention. Examples of alternatives to the plurality of wires 12 including metallic and nonmetallic ropes and cables, flexible or rigid strips or rods, blocks, joists, trusses, and the like.
It should be evident that this disclosure is by way of example and that various changes maybe made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
The present application claims the benefit of U.S. Provisional Application No. 60/600,597 filed on Aug. 11, 2004, currently pending, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60600597 | Aug 2004 | US |
