The invention relates to wall, roof and floor panels used in buildings.
Description of Prior Art
The building industry has developed what is known as Exterior Insulation and Finish Systems,(EIFS) which are primarily non-loadbearing curtain walls. A descriptive monograph by the Construction Specifications Institute is cited. EIFS panels typically consist of steel or wood studs, exterior and interior gypsum boards with polystyrene boards attached with an adhesive to the exterior face. The polystyrene boards are covered with a lightweitht glass fiber mesh, a polymer-based adhesive and synthetic stucco. The stud cavity is filled with fiberglass insulation. These systems are found to deteriorate due to the formation of moisture inside the stud cavity, which has caused the water-sensitive gypsum to deteriorate. Corrective measures include drainage systems, such as that disclosed by U.S. Pat. No. 5,826,388.
Foam Plastic Concrete Forms.
Many wall systems consist of concrete molds made of polystyrene to hold columns of concrete. In U.S. Pat. No. 4,879,855 Berrenberg discloses fusing polystyrene to steel diamond mesh inside special molds. Other patents have been granted that disclose similar end products and methods, with novel differences in the reinforcing members and their relationship to other members. Each design uses a custom mold in factories with procedures for controlling variables in raw materials and the environment. Building Code acceptance of these products generally requires special factory inspections by approved inspection agencies. The continuing acceptance of the products of the Berrenberg and similar patents teach that steel reinforcing members can be successfully bonded to polystyrene in molds.
TRIANGULAR WIRE TRUSS SYSTEMS similar to those in this invention are used with other foam plastic systems. U.S. Pat. No. 4,297,820 describes one of these systems. The trusses are typically not more than 4 inches deep and vertically spaced 3 to 6 inches apart with strips of polystyrene manually placed between the trusses. The relatively low load resistance of the individual trusses dictates this close spacing of the trusses. After installation of the polystyrene wire mesh is clipped or welded onto the truss wires to cover both faces of the panels. The panels are joined together at the building site with strips of wire mesh, typically using “C” rings crimped onto the mesh covering the panel faces. The mesh is then covered with sprayed concrete to create load-bearing panels. The panels are heavy, strong, lightweight and provide good insulation, but the wire mesh is typically installed at the factory without a weather barrier, and field attachment is not possible because the round wire mesh does not accept required mechanical fasteners. Sprayed concrete has been known to crack, and water has penetrated through these systems. U.S. Pat. No. 6,202,375 criticizes these systems, and references U.S. Pat. No. 4,297,820. The criticism includes the requirement for expensive manufacturing machinery to make the trusses and the special wire mesh.
U.S. Pat. No. 5,085,345, discloses a series of “zigzag shaped reinforcing rods” which are inserted into slits cut or melted into foam plastic panels prior to attachment of wire mesh. The tips of the rods are joined to a wire mesh that is sprayed with a cementitious material in the end use configuration. Use of weather barrier and choice of surface finish materials are both inhibited by the difficulty in attaching screws or other fasteners to round wires.
Steel Bonded to Foam Plastic
U.S. Pat. No. 4,241,555 discloses a panel with steel members bonded onto surfaces of a foam plastic panel. In this invention one panel is molded at time in a special mold. This disclosure demonstrates that thin strips of metal adhere to previously cured polystyrene when both are placed in a special mold.
U.S. Pat. No. 4,409,768 discloses a panel with steel structural members and wire-reinforced paper bonded to foam plastic that is in a liquid state prior to molding. Urethane foam may be the only foam plastic suitable for this process. These panels have vertical and horizontal support members exposed on the exterior faces. One panel is produced from each molding cycle.
U.S. Pat. No. 4,653,718 discloses a special mold that produces a single panel with steel reinforcing members molded inside. The process includes the attachment of metal strips pre-treated with an heat-activated adhesive and a wire mesh extending from the foam plastic core into a cavity formed on 1 panel surface. This patent demonstrates the validity of fusing a variety of metal reinforcing members with polystyrene in a special mold.
U.S. Pat. No. 4,620,569 discloses a method of fusing structural members with polystyrene to make a single panel in a special mold. The use of a supplemental adhesive to ensure effective bonding is described. Part of the panel framing members are utilized as the mold assembly, becoming part of the panel, and remaining exposed in the end use configuration.
U.S. Pat. No. 6,205,728 discloses a building panel utilizing folded metal sheets, wires, wire mesh, steel ribbons and other components assembled and combined either with foam plastic in a special mold or laminated together. The process includes an automated system of spool feeding wires, which may be computerized, pins, adhesives and other complexities. One claim discloses use of a synthetic corrugated structural sheet that is first coated with a heat-activated adhesive and fused inside a special mold that is described as being portable. The disclosure claims use of any generic or custom structural shapes, a wide variety of membranes for use on panel exteriors. This disclosure teaches that a wide variety of rigid shapes can be successfully bonded with foam plastic in a mold, including many of the shapes bonded inside molds in patents cited above. This disclosure does not claim any combination of wire trusses with flanged reinforcing members, the option of using either mechanical or adhesive attachment methods, the use of standard equipment to make and separate multiple panels, and other novel features of the present invention.
OBJECTS AND ADVANTAGES OF THE INVENTION
It is the object of this invention to provide novel solutions to a variety of problems that have been recognized in the following described systems since the building industry began extensive use of foam plastics.
The problem of moisture in EIFS panels is overcome by this invention because the stud cavity, with its condensation, is replaced with reinforced foam plastic.
This invention provides adequate structural strength, acceptance of a wide variety of wall, floor and roofing finish materials without the need for heavy concrete required by the concrete forms systems.
Structural Members Bonded to Foam Plastic
Problems inherent in these systems include quality control of the bonding process, which, if done in molds, requires highly specialized equipment and careful quality control by highly experienced personnel. The typical process used to bond structural members involves use of adhesives on foam plastic panel exteriors. An adhesive coating is placed on one or both surfaces being joined, pressure is applied, and curing time is allowed before the panels are moved. The materials and the processes require skilled workers capable of making adjustments to problems which inevitably arise. Some systems require complex cutting and shaping of the foam plastic in order to properly insert the steel members. These systems are typically have limited applications due to rigidity of the designs. In this invention building panels with adequate strength to resist a variety of axial, transverse and racking load requirements are produced without detailed fitting and bonding of each structural member. The load resistance and insulation values of the panels in this invention are altered according to the materials selected. The steel industry produces many sizes of wire trusses and flanged structural members that fit into the design of this invention. In this invention larger trusses, with larger flanged members fitted into them provide increased load-carrying capacity and greater resistance to heat transfer without adversely effecting the versatile attachment advantages or limiting choices of finish materials.
Wire Truss Triangle Systems
This invention overcomes multiple problems inherent in systems using wire trusses and round wire mesh on panel exteriors, such systems being generally limited to one finish material, which is concrete. The need for custom-cutting foam plastic segments and hand-fitting them between closely spaced trusses is overcome in this invention by fusing the foam plastic around the structural members and producing a monolithic panel. The use of reinforcing members provide support in the spaces between the trusses, allowing wider spacing.
In the typical wire truss systems the vertical joints that occur at each truss provide a path for water leakage, which problem is aggravated by the omission of a weather barrier. The outer surface of these systems is typically wire mesh, which does not allow screw attachment of weather barriers or conventional siding using mechanical fasteners.
Such systems depend on specialized wire-bending and fabricating machinery at each factory. This invention uses wire trusses and common steel framing members that are mass-produced for other uses and available at building material outlets all over the world.
This invention provides flat surfaces ideal for the installation of a weather barrier. In this invention the foam plastic is quickly molded around the steel structural members, eliminating joints inside each panel to invite water penetration.
The construction of special molds is eliminated by using the same molds that regularly make large foam plastic blocks. The same cutting equipment used to segment the blocks is used to separate the panels in this invention.
This invention provides convenient use of screws or other mechanical fasteners at proper spacing for the installation of gypsum boards, expanded metal lath, stucco, vinyl siding, hardboard siding and many other common mechanically fastened finish materials.
In this invention the insulation is not hand-placed but is properly located and firmly retained in place by total encapsulation in foam plastic. This invention also invites the use of adhesive finishes that serve as a weather barrier. Adhesive attachment is obtained because the flat steel screw bases (flanges) are concealed under a thin layer of foam plastic, and do not interrupt the smooth panel surfaces. The present invention comprises only 3 parts: 1. Off-the-shelf wire triangular trusses, 2: off -the-shelf steel flanged members, and 3: foam plastic. The machinery required to produce the panel in the present invention is the same foam plastic molding equipment used to produce and cut large foam plastic blocks, which are primarily polystyrene and urethane. Because expanded foam plastic is relatively inexpensive and bulky it is not economically feasible to ship it over long distances. The unexpanded styrene monomer and liquid urethane components are twenty 5 to 40 times more dense than the expanded end-use product. Consequently, foam plastic concentrates are shipped in the dense form to local plants where they are expanded and molded into large blocks. The blocks are then cut into marketable board sizes. The standardized foam plastic molding and cutting equipment used to produce the panels in this invention are located in permanent factories with effective quality control programs. The equipment used in this invention is widely distributed and in daily use. It is highly developed and efficiently operated with trained crews who overcome numerous quality-control problems caused by variables in raw materials, temperature, humidity, and other unpredictable circumstances.