WALL STRUCTURES MADE USING COMPOSITE WALL PANELS
Wall structures include: a wall frame made from a plurality of studs or other structural elements and optionally wall sheathing; first lightweight composite panels fastened to the wall frame to form a first wall substructure; and lightweight composite panels fastened to the wall frame to form a second wall substructure opposite the first. A complete wall can have an interior wall and exterior wall, two interior walls, or two exterior walls. Interior walls may include lightweight composite panels having a polymer, plaster, or paper show surface. Exterior walls may include lightweight composite panels with exterior finish, such as stucco, brick veneers, tiles, or stone. Lightweight composite panels are fastened to the sheathing and/or studs by screws, other mechanical fasteners, and/or adhesive. Lightweight composite panels include a foam core and fiber mesh reinforced cementitious (or other protective) layers formed on the foam core. Joints between adjacent panels are sealed using sealing tape, mesh tape and a seam coat, polyurethane foam, and/or other sealants.
This application claims the benefit of U.S. Provisional Application No. 63/744,115, filed Jan. 10, 2025, U.S. Provisional Application No. 63/729,637, filed Dec. 9, 2024, and U.S. Provisional Application No. 63/720,649, filed Nov. 14, 2024, which are incorporated by reference in their entirety.
BACKGROUND Technical FieldThis disclosure relates to wall structures and wall construction components and systems that include a wall frame made of studs or other structural elements and lightweight composite panels as essentially flat wall elements on opposite sides of the wall frame.
Related TechnologyHouses and other buildings are typically constructed using wood or metal studs to form a three-dimensional wall frame, which can include an interior wall on one side and an exterior wall on the other. Alternatively, both sides can be interior walls, such as interior walls separating rooms or walls dividing attached dwelling units such as apartments, town houses, and condominiums. In some cases, both sides can be exterior walls, such as fences, screen walls, sound barriers, walls that partially enclose carports, dumpster surrounds, and the like.
Interior walls of houses and other buildings are typically formed using drywall (e.g., gypsum board) to form a generally flat underlying wall surface, which can be painted, wallpapered, or treated with other desired finishes. A drywall panel typically consists of a layer of gypsum plaster sandwiched between two layers of paper. Gypsum plaster is made from calcium sulfate hemihydrate (or plaster of Paris) and water and mixed with fiber (typically paper and/or glass fiber), plasticizer, foaming agent, finely ground gypsum crystal as accelerator, EDTA, starch or other chelate as a retarder, and various additives that can increase mildew and fire resistance, lower water absorption (wax emulsion or silanes), and reduce creep (tartaric or boric acid). The board is then formed by sandwiching a core of the wet plaster mixture between two sheets of heavy paper or fiberglass mats. When the core sets, it is dried in a drying chamber, and the sandwich becomes rigid and strong enough for use as a building material.
While suitable for walls which are not exposed to water, ordinary gypsum board is not suitable for applications exposed to water and high humidity environments. Gypsum board is highly vulnerable to moisture due to the inherent properties of the materials that constitute it: gypsum, paper, and organic additives and binders. Gypsum will soften with exposure to moisture and turn into a gooey paste with prolonged immersion, such as during a flood or even in a bathroom when exposed to excessive water. Following water damage, drywall will likely need to be removed and replaced. Furthermore, the paper facings and organic additives mixed with the gypsum can be a breeding ground for mold.
For applications where walls will be exposed to moisture, such as in bathrooms, particularly showers and bathtubs, greenboard drywall and cement board are typically used. Greenboard is modified gypsum board in which the paper facing is treated with a waxy coating and chemicals that resist moisture and mildew. While water-resistant, greenboard is by no means waterproof. If water gets past the water-resistant layer, the gypsum core will absorb water and degrade similar to ordinary gypsum board. Cement board is a combination of cement and reinforcing fibers formed into sheets of varying thickness. Cement board is typically used as backer board for tile and other finishes. Cement board can be nailed or screwed to wood or steel studs to create a substrate for vertical tile and attached horizontally over plywood for tile floors, kitchen counters, and backsplashes. Cement board can also be used on the exterior of buildings as a base for exterior plaster (stucco) systems and sometimes as the finish system itself. Cement board adds impact resistance and strength to the wall surface as compared to gypsum boards. Cement board can be fabricated in thin sheets with polymer modified cements to allow bending for curved surfaces.
As tile backer board, cement board has better long-term performance than paper-faced gypsum core products because it does not physically break down in the continued presence of moisture or leaks and purportedly does not support mold or mildew growth. Cement board does provide a stronger bond and support with tiles than typical gypsum board but is typically made to breath and is not waterproof per se. It can absorb moisture but has excellent drying properties. In areas continually exposed to water (e.g., showers) a waterproofing material (e.g., plastic barrier) is usually placed behind the cement boards, or a trowel-applied waterproofing product (e.g., liquid membrane) can be applied to the face of the cement boards behind the finish system.
A major disadvantage of cement board is its relative high density (e.g., weight per square foot). Cement board weighs approximately twice as much as gypsum board, making handling by one person difficult. Cutting cement board must also be done with carbide-tipped tools and saw blades. Due to its hardness, pre-drilling of fasteners is often recommended. And because cement board contains fibers and many voids, pockets, and capillaries, it does in fact permit water penetration and can even support mold growth.
A major challenge with constructing conventional interior wall systems is the weight of conventional wall panels, including gypsum board, greenboard, and cement board. Another issue is that greenboard is moisture resistant but not waterproof, Therefore, even though it is somewhat lighter than cement board, it does not provide the same level of water protection. Another issue with traditional interior wallboards is their tendency to warp, have surface imperfections, or otherwise have defects that make them non-planar. As a result, it is often necessary to “float” tile and other surface finishes using thin set mortar to yield a planar finish. In the event that a planar wall surface (e.g., “level 5” surface) is required, such as when the surface finish includes paint, wallpaper or other pristine wall finish that may expose non-planar defects, it will typically be necessary to fill in surface defects and warping using plaster, which can be expensive and time consuming.
Exterior walls and wall finishes have their own unique challenges. In general, exterior walls are typically formed by fastening sheathing, typically wooden boards, to form exterior walls, followed by the application of a waterproof membrane, followed by the application of one or more surface finishes, most of which require several steps and layers. The wooden sheathing boards can be any kind of plywood. The currently preferred and most common wooden sheeting used to make exterior walls are oriented strand board (“OSB”) panels because of their favorable cost and combination of materials properties. OSB panels are typically used to form outer walls to which desired finishing elements can be attached, such as stucco, bricks, stone, panels, fixtures, and the like.
OSB is a type of engineered wood panel formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. OSB may have a rough and variegated surface with the individual strips of around 2.5 cm×15 cm (1.0 by 5.9 inches), lying unevenly across each other. OSB may be produced in a variety of types and thicknesses. OSB is sometimes confused with “chipboard”, a synonym for “particle board”, whose “chips” are of a size that a lay person would likely describe as “particles”. However, OSB is much stronger and durable than particle board and is frequently used in light steel frame house construction.
OSB panels are not waterproof but prone to swelling, rotting, and developing mold and mildew if exposed to water over time. They are typically wrapped with a waterproof polymer membrane to keep external water from contacting the OSB panels. The waterproof polymer membrane can also provide an air barrier that prevents unwanted air leakage. In addition, flashing, tape, and sealants can be used around joints to prevent water and air intrusion. Thereafter, one or more layers of other materials are applied over the polymer membrane to form a finished outer wall. At least one of the outer layers must be mechanically attached or connected to OSB panels to provide structure to hold the outer layers in place. Penetration of nails and screws through the waterproof polymer membrane, however, can potentially compromises its integrity and provide a pathway for moisture intrusion. Another issue is that OSB panels are flammable and emit toxic gases when ignited, such as during a house fire. Moreover, burning OSB panels emit embers that can quickly spread and ignite other fires, such as those which devastated entire neighborhoods near Los Angeles, California, in January 2025.
Modified OSB panels, such as those uses in the ZIP Wall Sheathing System (“ZIP System”), include OSB panels to which an integrated water-resistive barrier has been applied. This reportedly eliminates the need to wrap the ZIP System modified OSB panels with a waterproof polymer membrane, saving time and labor costs. ZIP System panels may also include an insulating foam layer positioned between the modified OSB units and underlying structural wall elements. This is known as the ZIP System Insulated R-Sheathing (“ZIP-R System”).
Stucco is a common finish applied to exterior walls of houses, apartments, town houses, condominiums, and other buildings. There are two main stucco systems: traditional stucco systems and exterior insulation and finish systems (EIFS). Both require the application of multiple layers of different materials that are heavy, time consuming, labor intensive, and in some cases bulky, hard to manipulate and apply, and potentially dangerous and when standing on scaffolding.
Accordingly, there remains a need for simplified methods and systems for constructing wall structures, including wall structures that have interior and exterior walls, two interior walls, or two exterior walls, of houses or other building structures that can reduce the number of required layers of materials, reduce time and cost, and improve safety compared to traditional wall structures and wall constructions systems.
SUMMARYDisclosed are methods and systems for constructing wall structures that include a wall frame and lightweight composite panels on (e.g., covering) first and second sides of the wall frame. The wall frame typically includes a plurality of studs, which can be wooden studs and/or metal studs, and optionally sheathing on at least one side of the wall frame. The wall structure may include an interior side and an exterior side opposite the interior side, such as an exterior wall structure of a house or other building. Alternatively, the wall structure may include a first interior side and a second interior side opposite the first interior side, such as an interior wall structure of a house or other building (e.g., within a single house of building or a wall that separates adjacent dwelling units, such as apartments, town houses, and condominiums). The wall structure may alternatively include a first exterior side and a second exterior side opposite the first exterior side, such as an exterior wall structure (e.g., a fence, sound barrier, carport wall, or dumpster enclosure).
In some embodiments, a method of constructing a wall structure comprises: (1) forming or providing a wall frame, the wall frame comprising (a) a plurality of studs or other structural elements and (b) optionally sheathing forming at least one side of the wall frame; (2) fastening a first plurality of lightweight composite panels to a first side of the wall frame to form a first wall substructure; and (3) fastening a second plurality of lightweight composite panels to a second side of the wall frame opposite the first side to form a second wall substructure opposite the first wall substructure, (4) the lightweight composite panels each comprising: (a) a foam core (e.g., polymer- or inorganic-based) having a first surface, a second surface opposite the first surface, a first edge forming a perimeter of the first surface, a second edge forming a perimeter of the second surface, and side surfaces extending between the first and second edges; (b) a first protective layer (e.g., first fiber mesh reinforced cementitious layer, thermoset polymer, or other rigid material) formed over and covering at least a portion of the first surface of the foam core; and (c) a second protective layer (e.g., second fiber mesh reinforced cementitious layer, thermoset polymer, or other rigid material) formed over and covering at least a portion of the second surface of the foam core, (d) wherein the lightweight composite panels are positioned so that one protective layer faces toward, and the other protective layer faces away from, the wall frame.
In some embodiments, a wall structure comprises: (1) a wall frame, the wall frame comprising (a) a plurality of studs or other structural elements and (b) optionally wall sheathing; (2) a first plurality of lightweight composite panels fastened to a first side of the wall frame and forming a first wall substructure; and (3) a second plurality of lightweight composite panels fastened to a second side of the wall frame opposite the first side to form a second wall substructure opposite the first wall substructure, (4) the lightweight composite panels each comprising: (a) a foam core (e.g., polymer- or inorganic-based) having a first surface, a second surface opposite the first surface, a first edge forming a perimeter of the first surface, a second edge forming a perimeter of the second surface, and side surfaces extending between the first and second edges; (b) a first protective layer (e.g., first fiber mesh reinforced cementitious layer, thermoset polymer, or other rigid material) formed over and covering at least a portion of the first surface of the foam core; and (c) a second protective layer (e.g., second fiber mesh reinforced cementitious layer, thermoset polymer, or other rigid material) formed over and covering at least a portion of the second surface of the foam core, (d) wherein the lightweight composite panels are positioned so that one protective layer faces toward, and the other protective layer faces away from, the wall frame.
In some embodiments, the wall frame comprises at least one of wooden studs or metal studs. In some cases, the wall frame may omit wall sheathing, in which case the first and second plurality of lightweight composite panels can be directly fastened to the studs (e.g., wooden studs or metal studs) and/or other structural elements of the wall frame. In other cases, the wall frame includes sheathing (e.g., plywood or OSB panels) fastened to the studs to form at least one of the first or second sides of the wall frame. In such cases, at least some of the first or second plurality of lightweight composite panels are fastened to the sheathing.
In some embodiments, the first wall substructure comprises an interior wall of the wall structure. In such case, at least some of the first plurality of lightweight composite panels forming the first wall substructure can have a show layer selected from a plaster finish, polymer finish, or paper facer on or covering the protective layer under the show layer. An interior finish, such as paint, wallpaper, and/or molding may be applied to the show layer or other exposed surface of the lightweight composite panels. In addition, or as an alternative, to lightweight composite panels with show layer, the first wall substructure can provide a substrate for kitchen or bathroom finishes, such as finishes selected from tile, stone, artificial stone, or polymer finish (e.g., cultured marble). In such case, the first plurality of lightweight composite panels may omit the plaster finish, polymer finish, or paper facer in order for the fiber mesh reinforced cementitious (or other protective) layer to provide a bonding surface to which kitchen or bathroom finishes can be attached (e.g., using thin set mortar, mastic, and/or adhesive).
In some embodiments, the second wall substructure may comprise a second interior wall of the wall structure, such as where the wall structure is an interior wall of a single building or dwelling unit or is a dividing wall between adjacent, connected dwelling units, such as apartments, town houses, and condominiums. In such cases, the second plurality of lightweight composite panels forming the second wall substructure may comprise lightweight composite panels having a show layer (e.g., plaster finish, polymer finish, or paper facer) on or covering the protective layer and/or may have an exposed protective layer that provides a substrate for kitchen or bathroom finishes, such as tile, stone, artificial stone, or polymer finish (e.g., cultured marble).
Alternatively, the second wall substructure may comprise an exterior wall of the wall structure, such as where the wall structure is or forms an exterior wall of a house or building. In such case, the wall frame may or may not include sheathing other than the second plurality of lightweight composite panels. In some cases, the wall frame may require conventional sheathing. For example, the wall frame may include plywood or OSB panels fastened to studs or other structure elements to form the second side of the wall frame to which lightweight composite panels are attached. In such case, the second plurality of lightweight composite panels can be fastened to the sheathing. The second plurality of lightweight composite panels may include an exterior finish applied thereto, such as stucco, brick veneers, stone, masonry, tiles, or other exterior finishes. The exterior finish can be factory applied before constructing the exterior wall and/or applied to an exterior surface of the lightweight composite panels after forming the exterior wall substructure.
In yet other embodiments, the first and second wall substructure may comprise first and second exterior walls of the wall structure, such as where the wall structure is an exterior wall structure, such as a fence, sound barrier, carport wall, or dumpster enclosure. In such cases, the first and second plurality of lightweight composite panels may include a finish applied, such as stucco, brick veneers, stone, masonry, tiles, or other exterior finishes.
In the case where the wall structure includes an exterior wall, the exterior-facing fiber mesh reinforced cementitious (or other protective) layer of the lightweight composite panels can provide a bonding substrate to which an exterior stucco finish can be directly applied and adhere without the need for lath and other underlying layers. Other surface finishes, such as brick veneers, stone, masonry, and tiles, can be applied and adhered directly to the exterior-facing fiber mesh reinforced cementitious (or other protective) layer, such as using thin set mortar or adhesives. Because the lightweight composite panels are strong, they can support relatively heavy loads, such as multiple layers of stucco finish, brick veneers, stone, masonry, tiles, light fixtures, and other fixtures using nails, other hangers, construction adhesive, or other wall attachment systems. The composite panels are lightweight yet waterproof and have high structural strength (i.e., high tensile and flexural strength and high toughness).
The first and second lightweight composite panels can be fastened to the wall frame using mechanical fasteners and adhesives known in the art, such as wood screws, self-drilling/tapping metal screws, nails, rivets, and construction adhesive. Mechanical fasteners, particularly in the case of an exterior wall or interior wall exposed to moisture, are advantageously corrosion resistant. Strips of tape can be used as a template to ensure proper placement of screws or other mechanical fasteners when fastening lightweight composite panels to studs or other structural elements of the wall frame. To prevent screws from tearing through the exterior fiber mesh reinforced cementitious (or other protective) layer, screws can be used with enlarged washers or pan head screws or screws with integrated washers having high surface area to distribute the pressure or load over a high surface area of the lightweight composite panel. Specialized washers with penetrating prongs can be used to limit rotation and penetration, preventing damage to the lightweight composite panels. Rectangular washers with multiple prongs on either side of the screw can be used to tie adjacent lightweight composite panels together.
In some embodiments, the fiber mesh reinforced cementitious (or other protective) layers of the lightweight composite panels can have a grid pattern or other discontinuity that provide a bonding substrate that facilitates adhesion of cementitious materials, thin set mortar, seam coats, stuccos (cement- and/or acrylic-based), adhesives, paint, or other coatings to surfaces of lightweight composite panels. For example, one or more stucco layers can directly adhere to the exterior-facing fiber mesh reinforced cementitious (or other protective) layer without the need for wire mesh, scratch coat, and brown coat used in conventional stucco systems. Nevertheless, it may be desirable to apply a layer of an appropriate seam coat (e.g., thin set mortar or fine-sanded stucco) to cover screws, sealants, holes, or other discontinuities prior to applying a finished stucco layer (which can be cement-based or acrylic-based stucco). Both cement-based stucco and acrylic-based stucco can adhere directly to the fiber mesh reinforced cementitious (or other protective) layer of the lightweight composite panels. Thus, a primer coat (e.g., primer paint or other polymer-based primer) is typically not required when using acrylic-based stucco (although this disclosure permits the use of a primer if desired).
The textured surface provided by the interior-facing fiber mesh reinforced cementitious (or other protective) layer provides a bonding substrate that facilitates adhesion of lightweight composite panels to the wall frame. In such cases, an appropriate adhesive, such as construction adhesive, can be used to adhere the lightweight composite panels to the wall frame, either in addition to or instead of screws or other mechanical fasteners. The use of an adhesive provides a much more continuous bond interface between lightweight composite panels and studs or exterior sheathing, thereby distributing the load more evenly and improving shear strength. Screws used by themselves may create discrete attachment points that theoretically may become potential weak points under high shear stresses. The use of adhesive attachment in addition to or instead of screws eliminates these discrete attachment points, creating a more solid and continuous bond that can better resist lateral forces. Screws, nails, rivets, mechanical fasteners, and adhesives are examples of means for fastening lightweight composite panels to studs or sheathing of a wall structure.
Additional features and advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the embodiments disclosed herein. It is to be understood that both the foregoing brief summary and the following detailed description are exemplary and not restrictive of the embodiments disclosed herein or as claimed.
Various objects, features, characteristics, and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification. In the Drawings, like reference numerals may be utilized to designate corresponding or similar parts in the various Figures, and the various elements depicted are not necessarily drawn to scale, wherein:
Disclosed are methods and systems for constructing interior and/or exterior wall structures that include a wall frame and lightweight composite panels on and/or fastened to first and second sides of the wall frame. The wall frame includes studs (e.g., wooden and/or metal studs), and may optionally including sheathing (e.g., OSB panels) on at least one side of the wall frame.
The wall structure may include or provide an interior side and an exterior side opposite the interior side, such as where the wall structure is or forms an exterior wall of a house or other building. Alternatively, the wall structure may include or provide a first interior side and a second interior side opposite the first interior side, such as wherein the wall structure is or forms an interior wall of a house or other building (e.g., within a single house of building or that separates adjacent dwelling units, such as apartments, town houses, and condominiums). The wall structure may alternatively include first and second exterior sides, such as where the wall structure is or forms an exterior wall that is not part of a house or building (e.g., a fence, sound barrier, carport wall, or dumpster enclosure).
Additional information relating to lightweight composite panels generally, modifications thereof, and various uses in making interior walls and exterior walls is disclosed in U.S. Application No. 63/686,489, filed Aug. 21, 2025. Additional information relating to lightweight composite panels that include a plaster show layer (e.g., for interior walls) is disclosed in U.S. application Ser. No. 19/306,817, filed Aug. 21, 2025. Additional information relating to lightweight composite panels that include a paper facer (e.g., for interior walls) is disclosed in U.S. application Ser. No. 19/343,312, filed Sep. 29, 2025. Additional information relating to lightweight composite panels that include a cured polymer show layer (e.g., for interior walls) is disclosed in U.S. application Ser. No. 19/343,601, filed Sep. 29, 2025. Additional information relating to lightweight composite panels and their use as substrates in making exterior walls with various applied finishes is disclosed in U.S. application Ser. No. 19/307,007, filed Aug. 21, 2025. Additional information relating to lightweight composite panels and their use as structural sheathing (e.g., for exterior walls and roofing decks) is disclosed in U.S. application Ser. No. 19/306,800, filed Aug. 21, 2025. Additional information relating to lightweight composite panels with a pre-applied drainage layer and their use in making exterior walls is disclosed in U.S. application Ser. No. 19/306,608, filed Aug. 21, 2025. Additional information relating to lightweight composite panels and their use in making subfloors and ceiling systems is disclosed in U.S. application Ser. No. 19/307,024, filed Aug. 21, 2025. Additional information relating to lightweight composite panels and their use in making vertical shaft liners is disclosed in U.S. Provisional Application No. 63/747,543, filed Jan. 21, 2025. The foregoing applications are incorporated by reference in their entirety.
In general, lightweight composite panels, whether used to make interior walls or exterior walls, are waterproof, can be made airtight so that little or no air flows through the walls, and can provide a surface to which a variety of different finishes can be directly applied. For example, in the case of interior walls, paint, wallpaper, and/or molding (e.g., wainscot, wood paneling, or crown molding) can be applied or adhered directly to the exposed surfaces of lightweight composite panels (e.g., that include a plaster, paper, or polymer show layer for smoothness). In the case of exterior walls, various exterior finishes can be applied or adhered directly to the exposed surfaces of lightweight composite panels without the need for lath or other underlying layers. Lightweight composite panels can function as structural sheathing in place of OSB panels.
Lightweight composite panels include a strong, yet lightweight, foam core sandwiched between relatively thin fiber mesh reinforced cementitious (or other protective) layers. As a result, the lightweight composite panels are strong and can support relatively heavy loads, such as multiple layers of stucco finish, brick veneers, stone, masonry, interior or exterior molding, tiles, light fixtures, and other fixtures using nails, other hangers, construction adhesive, or other wall attachment systems. The lightweight composite panels are lightweight yet waterproof and have high structural strength (i.e., high tensile and flexural strength and high toughness). In some embodiments lightweight composite panels can function as a shear wall but are much lighter than OSB and plywood panels. The exterior-facing fiber mesh reinforced cementitious (or other protective) layer can have a textured surface or grid pattern, which provides a bonding surface that facilitates application of adhesives, thin sent mortar, stucco, or other materials thereto. The lightweight composite panels can be cut, drilled, and screwed, fastened and/or glued onto structural elements of wall frames of buildings, such as studs and sheathing. The interior-facing fiber mesh reinforced cementitious (or other protective) layer can provide a bonding surface that facilitates adhesion of lightweight composite panels to an exterior wall structure.
By way of example,
As illustrated in
It will be appreciated that the wall structure 400 illustrated in
The first and second lightweight composite panels 604, 606 can be fastened to the wall frame 602, such as to the studs, using any fastening means known in the art, such as wood screws, self-drilling/tapping metal screws, rivets, nails, construction adhesive, and combinations thereof. As illustrated in
In some embodiments, specialized washers with penetrating prongs can be used to fasten lightweight composite panels to wall frames (see discussion of
In some embodiments, the length of penetrating prongs of the washers can be made to correspond to the cross-sectional thickness of the lightweight composite panels used to make a wall structure. Advantageously, the length of the penetrating prongs can be slightly less than, equal, or slightly exceed the cross-sectional thickness of the lightweight composite panels. This allows the penetrating prongs to penetrate all the way through the foam core and the interior fiber mesh reinforced cementitious (or other protective) layer and make abutment with studs, sheathing, or other structural element of the wall frame. This provides a stop that limits further movement of the enlarged washer toward the lightweight composite panel, preventing unwanted crushing of the lightweight composite panel and ensuring that the screw and washer ensemble does not break through and damage the exterior fiber mesh reinforced cementitious (or other protective) layer. However, it may be desirable for the length of the prongs to permit slight compression of the exterior fiber mesh reinforced cementitious (or other protective) layer without damaging it. This ensures that appropriately strong pressure is applied by the washer to the exterior fiber mesh reinforced cementitious (or other protective) layer to securely fasten the lightweight composite panels to a wall frame. Where the underlying studs or other structural element are metal, the length of the penetrating prongs can be approximately equal to or slightly less than the cross-sectional thickness of the lightweight composite (or other protective). Alternatively, where the underlying studs, sheathing, or other structural elements are made of wood, the length of the penetrating prongs can be the same as or slightly greater than the cross-sectional thickness of the lightweight composite (or other protective) in order to for the prongs to partially penetrate into the wood, thereby potentially further increasing the lateral and shear strength provided by the lightweight composite (or other protective) of a wall structure, such as an exterior wall structure to which an exterior finish is applied.
In some embodiments, the fiber mesh reinforced cementitious (or other protective) layers of the lightweight composite panels can have a grid pattern or other discontinuity that facilitates adhesion of cementitious materials, thin set mortar, stucco (cement- and acrylic-based), adhesives, paint, or other coatings to exposed surfaces of the lightweight composite panels. For example, one or more stucco layers can directly adhere to the exterior-facing fiber mesh reinforced cementitious (or other protective) layer without the need for wire mesh, scratch coat, and brown coat used in conventional stucco systems. Nevertheless, it may be desirable to apply patches of an appropriate seam coat (e.g., thin set mortar or fine-sanded stucco) to cover screws, washers, sealants, holes, fiber mesh tape, or other discontinuities prior to applying a finished stucco layer (which can be cementitious or acrylic based).
In some embodiments, where lightweight composite panels form an exterior wall of a wall structure, a drainage layer can be optionally positioned between wall sheathing (e.g., OSB or other wooden sheathing) and lightweight composite panels to which an exterior finish is applied to facilitate removal of water and prevent damage beneath the exterior finish.
II. Lightweight Composite PanelsThe wall structures disclosed herein include lightweight composite panels on or fastened to both sides of the wall frame. Lightweight composite panels can be used to make both interior and exterior wall structures to which one or more interior and/or exterior finishes can be applied. Lightweight composite panels comprise a strong, yet lightweight, foam core and a layer of fiber mesh reinforced cementitious composition (or other protective layer) on opposing sides of the foam core. As a result, the lightweight composite panels are strong and can support relatively heavy loads, such as decorative or structural features attached to wall structure. Examples include, but are not limited to, paint, wallpaper, molding, stucco (underlying and finish layers), brick veneers, stone, masonry, shingles, clay tiles, light fixtures, sheet metal, and fixtures.
A. Core Structure and Manufacture of Lightweight Composite PanelsThe cross-sectional thickness of lightweight composite panels 700a, 700b, 700c can be selected based on a combination of desired properties for their intended use, such as strength, insulation, spacing between wall elements, and the like. As illustrated in
Alternatively, the foam cores 710, 710a, 710b, 710c discussed above can be made from a different polymer foam material, such as, but not limited to, expanded polystyrene foam (EPS), polyisocyanurate foam, polyurethane (PUR) foam, phenolic polymer (e.g., phenol-formaldehyde) foam, melamine polymer (e.g., melamine-formaldehyde) foam, and/or other thermoplastic or thermoset polymer known in the art that can be formed into rigid or semi-rigid foam layers. An advantage of thermoset polymer foam materials is they are generally more fire- and heat-resistant than thermoplastic polymers, with thermoset phenolic polymers in particular providing a high level of fire and heat resistance.
The properties of various polymers that can be used to make foam core layers 110, 210 are set forth in Tables 1-3.
With reference to
The lightweight foam core is typically made from extruded polystyrene foam (XPS), but can alternately comprise expanded polystyrene foam (EPS), polyisocyanurate foam, polyurethane (PUR) foam, phenolic polymer (e.g., phenol-formaldehyde) foam, melamine polymer (e.g., melamine-formaldehyde) foam, and/or other thermoplastic or thermoset polymer known in the art that can be formed into rigid or semi-rigid foam layers. The lightweight foam core can be made of closed cell polystyrene foam to provide a water-resistant barrier (e.g., 100% waterproof).
Alternatively, the foam core may comprise an inorganic foam, such as a refractory foam material, to provide additional fire-resistance. Examples include expanded perlite (e.g., expanded spheres or microspheres), vermiculite, pumice, ceramic microspheres, hollow glass spheres, glass foam, ceramic foam, expanded silica gel, aerogel, other silicate foams, porous wollastonite, metakaolin, urea-silicate foam, SiOC/SiC foam, refractory foams, graphene, and the like. The inorganic foam core may include optional reinforcement fibers (cellulosic, basalt, E-glass, or carbon), and optional additives including hydrophobes, biocides, and phase-change or intumescent materials. The inorganic foam core can resist melting even when exposed to fire or intense heat in order for the lightweight composite panel to maintain its structural integrity.
In some embodiments, lightweight composite panels are manufactured by applying a fiber (e.g., fiberglass) mesh and cementitious or curable resin composition onto at least one surface of the inorganic foam core and causing or allowing the cementitious or curable resin composition to harden. The fiber mesh can be embedded in the cementitious or curable resin composition to enhance strength, increase toughness, and prevent cracking. In some embodiments, a fresh cementitious composition comprises mixture products of hydraulic cement, silicon dioxide powder, calcium oxide, iron oxide, plaster of Paris (gypsum hemihydrate), water-reducing agent, defoamer, styrene, and acrylic acid. The hydraulic cement typically includes Portland cement, but may also include supplementary cementitious materials (SCMs), such as ground granulated blast furnace slag (GGBFS), fly ash, natural pozzolan, silica fume, microsilica, metakaoline, ground glass, calcined clay, finely ground quartz, and the like. The fresh cementitious composition may include other components, such as natural hydraulic lime, calcium silicate, and/or expanded glass, which can increase fire and heat resistance.
The layers of fiber mesh reinforced cementitious composition are generally “thin” (e.g., typically less than about 3 mm, less than about 2.5 mm, less than about 2 mm, or less than about 1.5 mm, such as about 1 mm, or between about 0.5-3 mm, about 0.75-2.5 mm, or about 1-2 mm in cross-sectional thickness). The fiber mesh reinforced cementitious layers can be very lightweight yet waterproof and have high structural strength (i.e., high tensile and flexural strength and high toughness). The fiber mesh component is typically fiberglass fiber or glass filament mesh, but can be made of other strong fibers or filaments, such as carbon fibers or filaments. In some embodiments, fiberglass mesh is formed of an alkali-resistant material and may have nominal mesh size of 4×4 mm with a strand diameter of about 0.5-1.0 mm.
In some embodiments, the fresh cementitious composition comprises mixture products of water, hydraulic cement, silicon dioxide powder, calcium oxide, iron oxide, plaster of Paris (gypsum hemihydrate), water-reducing agent, defoamer, styrene, and acrylic acid. The fresh cementitious composition may optionally include supplementary cementitious materials (SCMs), such as ground granulated blast furnace slag (GGBFS), fly ash, natural pozzolan, silica fume, microsilica, metakaoline, ground glass, calcined clay, finely ground quartz, limestone powder, and the like. The cementitious composition may include other components, such as natural hydraulic lime, calcium silicate, and/or expanded glass, which can increase fire and heat resistance.
In the case where it is desired for lightweight composite panels to have beveled edges (e.g., to accommodate mesh tape and wall patch to join adjacent lightweight composite panels together), the fiber mesh reinforced cementitious layer can be applied before or after forming beveled edges in the form core, preferably after forming beveled edges to create a continuous fiber mesh reinforced cementitious layer across the entire surface of the lightweight composite panel.
In a more particular embodiment, the cementitious composition applied to the outer surfaces of the foam core to form fiber mesh reinforced cementitious layers of the lightweight composite panels can be formed by mixing together the following components (expressed in weight percent) to form a fresh flowable cementitious composition, which is applied to the foam core surfaces, together with fiber mesh, and then allowed to harden or cure:
The hydraulic cement typically includes Portland cement clinker interground with gypsum for set control, but may also include other interground minerals, such as limestone filler (e.g., 5-10% by weight of the hydraulic cement), and optionally one or more supplementary cementitious materials (SCMs), such as ground granulated blast furnace slag (GGBFS), fly ash, natural pozzolan, silica fume, microsilica, metakaoline, ground glass, calcined clay, finely ground quartz, and the like. The silicon dioxide can be 150 mesh ground quartz sand. The water reducer can be a low-range water reducer, such as a compound of carboxylic acid grafted multi-polymer and other effective additives. The defoamer can reduce the surface tension of water, solution, suspension, etc., prevent the formation of foam, or reduce or eliminate the original foam. The main component of the defoamer can be polydimethylsiloxane (Me3SiO(Me2SiO)nSiMe3) (Me=methyl). In the case where very fine SCMs (e.g., silica fume, microsilica, or metakaoline), it may be desirable to use a high range water reducer (e.g., polycarboxylate ether) to obtain good flow. The styrene and acrylic acid components, which may be a copolymer, can form a chemical bond to the extruded polystyrene foam core, in addition to the physical bond.
The components of the cementitious composition can be mixed by high-performance mixing equipment through precise batching, and then fed into a mixing barrel in sequence for high-speed dispersion and mixing, thus yielding a fresh cementitious mixture. The fresh cementitious mixture is blended in a tank to make it into liquid or plastic form. The liquid cementitious mixture is then pumped into a machine variously called a “waterfall machine,” commonly known as a “curtain coater” or enrobing “coater/machine”, which has flow control of the liquid cementitious mixture and which will apply the liquid cementitious mixture onto surfaces of an extruded polystyrene foam sheet or other material to be coated. The liquid cementitious mixture is applied like a waterfall or curtain through a blade applicator to evenly apply it to the polymer foam surfaces or other surface to be coated. The product is then cured and left to stand for approximately 7 days as usual practice. However, if ambient conditions are dry and hot, the curing period could be shortened to approximately 3-4 days.
In general, the hardened fiber mesh reinforced cementitious composition can adhere and bond strongly to the polymer or inorganic foam core to form a strong lightweight composite panel structure that does not delaminate. The bond between the cementitious layers and the foam layer is likely a combination of physical and chemical interactions. When applied to the polymer or inorganic foam layer, the liquid cementitious composition can penetrate into surface pores of the foam layer, which upon hardening of the cementitious composition, forms a strong mechanical bond. This bond can be further enhanced through the inclusion of very fine pozzolans, such as silica fume, microsilica, or metakaoline on the cementitious composition, which creates a very high strength cementitious layer and are able to fill very small micropores. The polymer components of the cementitious composition may also interact with components of the foam layer to form a type of chemical bond between the cementitious layers and the foam (e.g., polymer) layer. Regardless of how bonding occurs, it is demonstrably very strong and does not delaminate during specified use. Curable resins also adhere and bond strongly to the foam core.
In some embodiments, when manufacturing the lightweight composite panel structure, the fiberglass mesh is first laid down on a polymer (e.g., extruded polystyrene) or inorganic foam sheet. A transportation belt then transports the foam sheet with the fiberglass mesh through the waterfall machine (commonly known as a “curtain coater” or enrobing “coater/machine”), which causes the liquid cementitious mixture to flow down like a waterfall or curtain, with control of the liquid cementitious mixture flow, onto the foam sheet or other substrate. In this way, the fiberglass mesh becomes embedded in the liquid cementitious mixture and essentially floats in the middle of the cementitious mixture. In other words, a portion of the liquid cementitious mixture will be positioned between the fiberglass mesh and the foam sheet in order to directly adhere to the foam sheet, and another portion of the liquid cementitious mixture will cover and encapsulate the fiber mesh to form the top surface of the lightweight composite panel structure. The result is a layered composite structure, with an interior polymer or inorganic foam sheet, an underlying layer of cementitious composition in direct contact with the foam sheet, a fiberglass mesh in the middle, and a top layer of cementitious composition covering the fiberglass mesh.
In addition to, or instead of, a fiber mesh reinformed cementitious layer, one or both protective layers of the lightweight composite panel may comprise other materials in addition to or instead of the cementitious composition. Examples include one or more of rigid magnesium oxide material, water-resistant polymer, or a composite material comprising a resin or polymer with embedded fibers, fiber mesh, fabric, scrim, felt, or non-woven. The material forming the fibers, fiber mesh, fabric, scrim, felt, or non-woven can be selected from plant fibers, polymer fibers, and inorganic fibers (e.g., basalt, rock wool, and the like). The resin or polymer may comprise a thermoplastic or thermoset material, such as UV-cured resins, polypropylene, polycarbonate, polyethylene terephthalate, polystyrene, acrylate, methacrylate, polyurea, polyaspartic, or epoxy. Protective layers of thermoset polymer can be slightly thicker than fiber mesh reinforced cementitious layers, such as between about 1-5 mm or about 2-3 mm.
Polyurea is a type of elastomer that is derived from the reaction product of an isocyanate component and an amine component. The isocyanate can be aromatic or aliphatic in nature. It can be monomer, polymer, or any variant reaction of isocyanates, quasi-prepolymer or a prepolymer. The prepolymer, or quasi-prepolymer, can be made of an amine-terminated polymer resin, or a hydroxyl-terminated polymer resin. The resin blend can include amine-terminated polymer resins and/or amine-terminated chain extenders. The resin blend may also contain additives or non-primary components, such as pigments pre-dispersed in a polyol carrier. Normally, the resin blend does not contain a catalyst. This is because the reaction between an isocyanate and amine is extremely fast and hence does not need catalysis.
The chemical structure of polyurea is as follows:
In a polyurea, alternating monomer units of isocyanates and amines react with each other to form urea linkages, as shown below.
Polyaspartic resin is a solvent-free, aliphatic amine coating material based on aspartic acid, polyaspartic acid, or polyaspartic ester, which reacts with an isocyanate to create extremely durable protective coatings with rapid cure times, excellent abrasion resistance. An example of a curable polyaspartic resin has the following reactants and final cured polymer structure:
The curable resin can be applied by spray coating while in a flowable state to one or both surfaces of the foam core and allowing it to cure and form a solid protective layer. Multiple parts of the curable resin can be mixed just prior to entering or within the nozzle used to spray coat the foam core. Where it is desired to incorporate a fiberglass mesh sheet in the polymer layer, an initial coating of curable resin can be applied to the foam core, followed by applying the fiberglass mesh sheet over the resin, followed by applying a final coating of the curable resin.
In some embodiments, the outlines of the fiberglass mesh embedded within the hardened cementitious or cured resin layer can be visible and form a grid-like texture that improves adhesion of structural and/or decorative materials thereto, such as cementitious coatings, adhesives, stucco, paint, brick veneers, masonry, stone veneers, shingles, clay tiles, metal cladding, and the like. For example, one or more stucco layers can directly adhere to the fiber mesh reinforced cementitious layer without the need for wire mesh, scratch coat, and brown coat used in conventional stucco systems. Nevertheless, it may be desirable to apply a layer of thin set mortar to cover screws, sealants, holes, or other discontinuities in the lightweight composite panels prior to applying a finished stucco layer (which can be cementitious or acrylic based).
The textured surface provided by the fiber mesh reinforced cementitious layer can facilitate adhesion of lightweight composite panels to a wall frame, such as an exterior side of a wall frame or other wall structure, in order for the lightweight composite panels to provide a substrate for application of one or more finishes. In some embodiments, an appropriate adhesive, such as construction adhesive, can be used to adhere lightweight composite panels to an exterior wall frame or structure, including studs and/or exterior sheathing, either in addition to or instead of screws or other mechanical fasteners. The use of an adhesive provides a much more continuous bond interface between the lightweight composite panels and studs or sheathing, thereby distributing the load more evenly and improving shear strength of the wall structure. The use of adhesive attachment in addition to or instead of screws can eliminate discrete attachment points, creating a more solid and continuous bond that can better resist lateral forces and improve shear strength of the wall structure.
The lightweight composite panels are typically rectangular in shape, with a constant cross sectional thickness. The lightweight composite panels can have multiple uses, including for interior walls that are exposed to moisture, providing a substrate to which tiles, stones, or other surface treatments can be applied, other interior walls (e.g., plaster coated composite panels), exterior sheathing that complements or replaces OSB panels, as a substrate for stucco, brick veneers, masonry, natural or manufactured stone, or other finishes, roofing boards that function as underlayment for shingles, roofing tiles, metal roofing sheets, wood shakes, and the like, floor underlayment, ceiling panels, and shaft liners. The lightweight composite panels can be modified for specialized uses, such as by applying a decoupling layer, drainage plane, rain screen, dimple board, factory applied dimples or dots, or bleed layer to facilitate removal of moisture between the lightweight composite panels and exterior wall or roof structures.
Advantages of the lightweight composite panels include: being lightweight (i.e., approximately ⅓ the weight of gypsum drywall and approximately ⅙ the weight of cement board); 100% waterproof as a result of the core being high density closed cell foam; high strength, high thermal insulation (i.e., proving approximately 4 times greater insulation than gypsum drywall), adequate soundproofing, and textured outer layer ideal for applying cement and glue for additional products. Further, due to the two layers of fiber reinforced cementitious composition, one on each side, a nail or screw entering both external layers can hold significant weight, substantially more weight than gypsum board.
B. Composite Wall Panels With Polymer LayerIn order for lightweight composite panels to function as an interior drywall replacement, such as where it may be desired to apply an interior finish, such as paint, wallpaper, or molding (e.g., wainscot, wood paneling, or crown molding), the lightweight composite panel functions as a core composite panel structure that is modified by forming a polymer finish layer over at least one of the fiber mesh reinforced cementitious (or other protective) layers of the core composite panel structure. The polymer finish layer can be generally white in color, although other colors are possible if desired. Additional information relating to the manufacture and use of composite wall panels with a polymer finish is disclosed in U.S. application Ser. No. 19/343,601, filed Sep. 29, 2025, which is incorporated by reference.
Composite wall panels can include a light colored (e.g., white or off white) polymer finish layer formed over at least the exterior surface of the exterior fiber mesh reinforced cementitious (or other protective) layer, and optionally the side edges, giving the composite wall panels the appearance of wallboard without paper. Because composite wall panels can include fiber mesh reinforced cementitious (or other protective) layers, along with a waterproof interior polymer or inorganic foam core, they are both waterproof and substantially stronger than conventional gypsum drywall. The composite wall panels can be used, for example, in embodiments where it is desired to construct a complete wall structure that includes two interior walls or, alternatively, an interior wall and an exterior wall made with composite wall panels to which an exterior finish is applied.
The composite wall panels include a lightweight foam core sandwiched between two fiber mesh reinforced cementitious (or other protective) layers, but with an additional polymer finish layer applied on at least one protective layer to provide a polymer finish to yield wall panels that can substitute for gypsum drywall. The polymer finish layer can be textured, sanded, painted, wallpapered, and the like, similar to the surface of conventional gypsum wallboard. However, the polymer finish layer can have a desired surface finish that eliminates the requirement to apply a finish to the paper surface of conventional gypsum drywall. The composite wall panels can be attached to wood or metal studs or other wall or ceiling structural elements using screws, nails, adhesives, or other known attachment means. The composite wall panels can also include bevels (e.g., 2 or 4) to permit placement of multiple adjacent composite wall panels, followed by application of drywall patch (taping and mudding) to hide the joints. Specialized connectors, such as washers with enlarged surfaces and penetrating prongs can be used to join adjacent composite wall panels together.
The composite wall panels include a finish layer that comprises a curable resin applied to one or both sides of the core composite panel structure and that is caused or allowed to cure. The curable resin coating layer can serve as the final surface layer for the composite wall panels. In some embodiments, the finish layer can be formed from a light-curable, UV-curable, and/or chemical-curable resin, examples of which include, but are not limited to, acrylic or methacrylic resins, aliphatic urethane acrylates, epoxy acrylates, polyester acrylates, and hybrids. An appropriate resin can be selected based on target hardness, flexibility, and adhesion properties. UV-curable resins include a photoinitiator to trigger polymerization upon UV exposure. Examples include, but are not limited to, benzoin ethers, acylphosphine oxides (e.g., diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, or TPO), and benzophenones depending on desired cure rate and depth. Alternatively, chemical cure resins known in the art can be used, such as the UV-curable resins mentioned above but which are modified to include a chemical initiator instead of, or in addition to, the photoinitiator. Examples of chemical initiators include peroxides (e.g., benzoyl peroxide), which are sometimes paired with an amine in a 2-part system, and cross-linkers.
In some embodiments, it may be desirable to apply and process the polymer finish layer in a manner that provides what is known in the industry as “level 5” finish, or “drywall finish level 5”. A level 5 finish is defined by the Gypsum Association, the trade association for drywall professionals, and is a premium finish that typically commands a much higher cost than lower level finishes. Providing a composite wall panel having a level 5 finish can eliminate the many steps and time required to prepare ordinary drywall to have a level 5 finish. This saves labor costs and time, including the time required for each coat of joint compound to dry and then be sanded.
Reference is made to
The fiber mesh reinforced cementitious layers 820, 830 provide several advantages. The textured surface of the second fiber mesh reinforced cementitious layer 830 can enhance the bond strength of the finish layer 840 and prevent delamination. Because the first fiber mesh reinforced cementitious layer 820 does not include a finish layer it can have a textured surface that facilitates adhesion of the composite wall panel 800 to wall frame studs, ceiling joints, or other underlying structure using an adhesive or glue. In addition, the first and second fiber mesh reinforced cementitious (or other protective) layers 820, 830 provide high strength, which permits the composite wall panel 800 to support relatively heavy loads, such as pictures, television sets, or other appliances using nails or screws, particularly if they can penetrate through both the first and second fiber mesh reinforced cementitious (or other protective) layers 820, 830.
The textured surface of the second fiber mesh reinforced cementitious (or other protective) layer 830 can enhance the bond strength of the finish layer 840, which prevents delamination. The first fiber mesh reinforced cementitious (or other protective) layer 820 can have a textured surface that facilitates adhesion of the composite wall panel 800 to wall frame studs, ceiling joists, or other underlying structure. The first and second fiber mesh reinforced cementitious (or other protective) layers 820, 830 provide high strength, which permits the composite wall panel 800 to support relatively heavy loads, such as pictures, television sets, or other appliances using nails or screws, particularly if they can penetrate through both the first and second fiber mesh reinforced cementitious (or other protective) layers 820, 830.
Instead of the polymer layer discussed in the previous section, lightweight composite panels can be modified by forming a polymer finish layer over at least one of the fiber mesh reinforced cementitious (or other protective) layers of the core composite panel structure. The plaster finish layer can be generally white in color, although other colors are possible if desired. Additional information relating to the manufacture and use of composite wall panels with plaster finish (“composite plaster panels”) is disclosed in U.S. patent application Ser. No. 19/306,817, filed Aug. 21, 2025, which is incorporated by reference.
The composite plaster panels are made in essentially the same way as composite wall panels with polymer layer discussed in the previous section and will have the same general structure, except that the plaster layer replaces the polymer layer. As such,
Reference is again made to
The textured surface of the second fiber mesh reinforced cementitious (or other protective) layer 830 can enhance the bond strength of the plaster layer 840, which prevents delamination. The first fiber mesh reinforced cementitious (or other protective) layer 820 can have a textured surface that facilitates adhesion of the composite plaster panel 800 to wall frame studs, ceiling joists, or other underlying structure. The first and second fiber mesh reinforced cementitious (or other protective) layers 820, 830 provide high strength, which permits the composite plaster panel 800 to support relatively heavy loads, such as pictures, television sets, or other appliances using nails or screws, particularly if they can penetrate through both the first and second fiber mesh reinforced cementitious (or other protective) layers 820, 830.
In some embodiments, a fresh plaster composition used to form the plaster layer comprises mixture products of water, hydraulic cement, preferably white cement, calcium carbonate, aluminum oxide, silicon dioxide, cellulose ether, and latex. The fresh plaster composition may optionally include supplementary cementitious materials (SCMs), such as ground granulated blast furnace slag (GGBFS), fly ash, natural pozzolan, silica fume, microsilica, metakaoline, ground glass, calcined clay, finely ground quartz, limestone powder, and the like. The cementitious composition may include other components, such as natural hydraulic lime, calcium silicate, and/or expanded glass, which can increase fire and heat resistance.
In a more particular embodiment, the fresh plaster composition used to form one or more plaster layers can be formed by mixing together the following components (expressed in weight percent) to form a fresh, flowable plaster composition, which is applied to one or both sides of the core composite panel structure, and then allowed to harden or cure:
The hydraulic cement typically includes Portland cement, preferably white cement for aesthetic reasons, but may also include supplementary cementitious materials (SCMs), such as ground granulated blast furnace slag (GGBFS), fly ash, natural pozzolan, silica fume, microsilica, metakaoline, ground glass, calcined clay, finely ground quartz, and the like. The Portland cement comprises ground cement clinker interground with gypsum for set control and limestone as a filler. For aesthetic reasons, SCMs, when included, are preferably white or light colored. The silicon dioxide can be 150 mesh ground quartz sand. The latex powder can be redispersible 558 latex, which can be an ethylene/vinyl acetate copolymer, vinyl acetate/versatate copolymer, acrylic copolymer, etc. The latex powder can improve adhesion of the plaster layer to a cementitious layer.
The dry components of the plaster composition, known euphemistically as “putty powder”, can be dry mixed in a mixer to form an evenly mixed dry blend. Then the water is added to the mixture to form a fresh flowable plaster composition that can be sprayed. A spray gun is used to apply the fresh plaster composition to the fiber mesh reinforced cementitious layer of a basic lightweight composite panel (e.g., with or without beveled edges). The amount of plaster composition applied should be sufficient to cover the fiber mesh reinforced cementitious layer so that the grid-like texture is no longer visible, forming a smooth surface (or surface having a desired texture). The plaster composition is then allowed to cure for 7 days to form a hardened surface, which can be polished if desired to yield a smooth surface.
In some embodiments it may be desirable to cut the beveled edges to a width of about 1.5 inches (e.g., 1-2 inches, or 1.25-1.75 inches). If any portion of the composite plaster panels includes exposed expanded polystyrene foam, a primer can be used to cover the exposed polystyrene foam to enhance strength and improved the bond of drywall patch to the composite plaster panels.
D. Laminated Composite Wall PanelsAnother version of lightweight composite panel that can be used to form an interior wall of a complete wall system includes a fiber-based sheet laminated over one or both sides of the core composite panel structure to yield a laminated composite wall panel. An intermediate polymer layer can optionally be formed over one or both sides of the core composite panel structure to form a smooth surface to which the fiber-based sheet layer can be applied. In some embodiments, the intermediate polymer layer can be the same polymer materials used above to form composite wall panels with polymer finish layer. The fiber-based sheet layer can be generally white or off white in color, although other colors are possible if desired. Additional information relating to the manufacture and use of laminated composite wall panels is disclosed in U.S. patent application Ser. No. 19/343,312, filed Sep. 29, 2025, which is incorporated by reference.
Laminated composite wall panels include a light colored (e.g., white or off white) fiber-based sheet layer formed over at least the exterior surface of the exterior fiber mesh reinforced cementitious (or other protective) layer, and optionally the side edges, giving the laminated composite wall panels the appearance of traditional wallboard but without a water-sensitive gypsum core. Because laminated composite wall panels can include fiber mesh reinforced cementitious (or other protective) layers, along with a waterproof interior polymer foam core, they are both waterproof and substantially stronger than conventional gypsum drywall. Moreover, the core composite panel structure is waterproof, providing extra safety if the laminated composite wall panels are inadvertently exposed to water. Even if the fiber-based sheet is damaged, the structural integrity of the composite wall panel structure is maintained and not compromised like traditional gypsum wallboard. Moreover, the fiber-based sheet layer can include a waterproofing material on or in the fiber-based sheet to protect it from moisture damage and absorption of deleterious substances and contaminants.
The fiber-based sheet layer may include any fiber-based sheet material, including but not limited to, paper, fabrics, wovens, non-wovens, and the like. The fibers in the fiber-based sheet layer may include organic and/or inorganic fibers or filaments. Thus, the term “fiber” may include fibers and/or filaments. Examples of organic fibers include natural fibers and synthetic fibers or filaments that are used to make paper, fabrics, wovens, non-wovens, and the like. Examples of inorganic fibers include glass fibers or filaments, carbon fibers or filaments, and the like.
The laminated composite wall panels include a lightweight foam core sandwiched between two fiber mesh reinforced cementitious (or other protective) layers, but with an additional fiber-based sheet applied on at least one protective layer to provide a fiber-based sheet finish to yield wall panels that can substitute for gypsum drywall. The fiber-based sheet layer can be skim-coated with plaster (e.g., drywall patch), painted, wallpapered, and the like, similar to the surface of conventional gypsum wallboard. The laminated composite wall panels can be attached to wood or metal studs or other wall or ceiling structural elements using screws, nails, adhesives, or other known attachment means. The laminated composite wall panels can also include bevels (e.g., 2 or 4) to permit placement of multiple adjacent laminated composite wall panels, followed by application of drywall patch (taping and mudding) to hide the joints. Specialized connectors, such as washers with enlarged surfaces and penetrating prongs can be used to join adjacent laminated composite wall panels together.
When included, the intermediate polymer layer beneath the fiber-based sheet layer can be formed from a light-curable, UV-curable, and/or chemical-curable resin, examples of which include, but are not limited to, acrylic or methacrylic resins, aliphatic urethane acrylates, epoxy acrylates, polyester acrylates, and hybrids. An appropriate resin can be selected based on target hardness, flexibility, and adhesion properties. UV-curable resins include a photoinitiator to trigger polymerization upon UV exposure. Examples include, but are not limited to, benzoin ethers, acylphosphine oxides (e.g., diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, or TPO), and benzophenones depending on desired cure rate and depth. Alternatively, chemical cure resins known in the art can be used, such as the UV-curable resins mentioned above but which are modified to include a chemical initiator instead of, or in addition to, the photoinitiator. Examples of chemical initiators include peroxides (e.g., benzoyl peroxide), which are sometimes paired with an amine in a 2-part system, and cross-linkers.
As discussed herein, lightweight composite panels can be used to form one or two exterior walls of a wall structure. In some cases, particularly where lightweight composite panels used to make an exterior wall are fastened over OSB panels or other wooden sheathing, it may be desirable to incorporate a drainage layer between the lightweight composite panels and wooden sheathing. The drainage layer facilitates the removal of liquid water and water vapor from between the sheathing and lightweight composite panels to prevent damage to the sheathing and possible mold growth. Additional information relating to the manufacture and use of composite wall panels with drainage layer is disclosed in U.S. application Ser. No. 19/306,826, filed Aug. 21, 2025, which is incorporated by reference.
The core composite panel structure is modified by attaching a drainage layer (e.g., polymer uncoupling membrane, embossment, drainage plane, rain screen, dimple board, factory applied raised dimples or dots, or bleed layer (collectively “drainage layer”) to an interior-facing surface that is designed to face a wall or roofing frame. The drainage layer provides a built-in drainage plane by providing spaced contact points that create a capillary break, enabling vertical drainage of incidental moisture. The drainage layer provides gaps and channels between the core composite panel structure and the underlying wall or roof structure (e.g., studs, trusses, and/or OSB sheathing) to permit moisture to collect and drain and/or evaporate, thereby protecting outer surface finishes and preventing or minimizing formation of mold, mildew, and structural damage of the underlying wall or roof structure and/or exterior finish, such as by freeze-thaw cycles, delamination, or other water-related issues.
The drainage layer can be applied to the core composite panel structure using waterproof adhesive or directly adhered to the cementitious composition or thermoset polymer used to make the protective layer on the interior side of the core composite panel structure. In some embodiments, the protective layer on the side of the core composite structure that is configured to be placed against sheathing or other structural elements may comprise a waterproof (e.g., polymer) material that is pre-formed or molded to include gaps and channels that can function as a drainage layer to facilitate moisture removal. In other embodiments, a built-in drainage plane can be formed by applying a field of raised adhesive dimples to the back surfaces of the lightweight composite building panel.
The drainage layers 1404a, 1404b can be attached to a surface of the core composite panel structures 1402a, 1402b using adhesives known in the art. In some embodiments, the drainage layers 1404a, 1404b can be adhered to the core composite panel structures 1402a, 1402b using a standard polymer modified mortar, such as the cementitious composition used to form the outer surface layers of the core composite panel structures 1402a, 1402b. In some embodiments, the protective layer on the side of the core composite panel structure 1402 that is configured to be placed against sheathing or other structural elements may comprise a waterproof (e.g., polymer) material that is pre-formed or molded to include gaps and channels that can function as a drainage layer to facilitate moisture removal.
The surface of the lightweight composite building panels 1400a, 1400b opposite the drainage layers 1404a, 1404b can be a fiber mesh reinforced cementitious layer that can be used to apply a desired exterior surface finish, such as stucco, brick veneers, masonry, tiles, stone veneers, shingles, and the like. The lightweight composite building panels 1400a, 1400b provide a waterproof exterior surface that also provides for moisture removal, such as to prevent growth of mold and mildew or structural damage to the underlying wall or roof structure.
The drainage layer can alternatively comprise factory-applied dimples to the back side of a lightweight composite building panel. A built-in drainage plane can be made by applying a field of raised adhesive dimples to the back surface of each lightweight composite building panel. These spaced contact points create a capillary break, enabling vertical drainage of incidental moisture. This method eliminates the need for separately installed rainscreen mats or drainage layers (either in the field or in the factory) while maintaining full panel-sheathing contact.
In a controlled factory setting, automated metered dispensers are configured to apply a substantially uniform grid of polymer-based dots or beads to the panel back. Each bead can be cured to a consistent height of about 1/16 inch to ¼ inch, maintaining an air gap between the panel and substrate.
The complete wall structure 1600 further includes a pair of second lightweight composite panels 1612a, 1612b fastened to the OSB sheathing 1606 on the side opposite the first lightweight composition panel 1608 using a plurality of exterior corrosion-resistant screws 1616 and enlarged washers 1618 to form an exterior wall of the complete wall structure 1600. Third and fourth lightweight composite panels 1612c, 1612d are fastened to the left and right ends of the wall frame 1602 using screws and enlarged washers (not shown) so that the wall frame 1602 is enclosed by lightweight composite panels on all four sides. The enlarged washers 1618 have penetrating prongs (not shown) embedded in the lightweight composite panels 1608, 1612 to prevent rotation of the washers 1618, increase gripping force, and limit how far the enlarged washers 1618 can be driven into the lightweight composite panels. The enlarged washers 1618 and penetrating prongs prevent the screws 1616 from breaking through, while allowing slight compression of, the exterior fiber mesh reinforced cementitious (or other protective) layer of the first, second, third, and fourth lightweight composite panels 1608, 1612 to prevent damage thereto while ensuring good fixation of the panels to the wall frame 1602.
With reference to the exterior wall portion of the wall structure 1600, a layer of water-proofing black paper 1610 is positioned between the OSB sheathing 1606 and the second lightweight composite panels 1612a, 1612b to protect the OSB sheathing 1606 from moisture ingress (i.e., in the unlikely event moisture would somehow collect beneath the otherwise waterproof lightweight composite panels 1612a, 1612b). Protecting the OSB sheathing 1606 from moisture prevents mold growth in and structural damage to the OSB sheathing 1606. A stucco finish 1626 is applied to the exterior fiber mesh reinforced cementitious (or other protective) layers of the second, third, and fourth lightweight composite panels 1612a, 1612b, 1612c, 1612d to form an exterior surface finish.
A vertical concourse of screws 1616 and enlarged washers 1618 are used to interconnect the adjacent second lightweight composite panels 1612a, 1612b fastened to the OSB sheathing 1606. A vertical strip of fiber mesh tape 1620 is placed over the screws 1616 and enlarged washers 1618 and a portion of the exterior fiber reinforced cementitious (or other protective) layers of the second lightweight composite panels 1312a, 1312b, followed by application of a vertical strip of an appropriate seam coat (e.g., thin set mortar or fine-sanded stucco) 1624 over the fiber mesh tape 1620, screws 1616 and enlarged washers 1618, and a portion of the exterior fiber reinforced cementitious (or other protective) layers to further tie the second lightweight composite panels 1612a, 1612b together. The seam coat provides a smooth surface and further helps prevent separation and potential formation of cracks in the stucco finish 1626 placed over the joint between the adjacent lightweight composite panels 1612a, 1612b. The same or different material used for the seam coat 1624 can be applied as a patch 1622 over screws 1616 and enlarged washers 1618 in other regions to form a smooth surface over which the stucco finish 1626 can be applied.
The complete wall structure 1600 includes first and second corners at the interfaces between the first lightweight composite panel 1608 and third and fourth lightweight composite panels 1612c, 1612d positioned at 90° angles. The first corner is illustrated as being tied together and protected by a strip of fiber mesh 1614a and a corner layer of an appropriate seam coat (not shown, e.g., thin set mortar or fine-sanded stucco) in which the fiber mesh fiber mesh 1614a is embedded. The second corner is illustrated as being tied together and protected by a rigid or semi-rigid corner bend 1614b, which can be made of metal or polymer, such as polyvinyl chloride (PVC), and a second corner layer of seam coat 1625 in which the corner bend 1614b is embedded. It will be understood that the fiber mesh 1614a and corner bend 1614b are alternative embodiments and need not be included in the same wall structure. Rather, some embodiments may use the fiber mesh 1614a for simplicity and cost and other embodiments may use the corner bend corner bend 1614b (e.g., to provide greater protection against mechanical damage caused by blunt force to the corners). The stucco finish 1626 (cement- or acrylic-based) is applied over the exterior-facing fiber mesh reinforced cementitious layer and the patch of seam coat 1625. A primer is typically not required when using acrylic-based stucco, although one can be used if desired.
A first lightweight composition panel 1610a is attached to the wooden studs 1404 on a second side of the wall frame 1602 opposite the first side by screws 1616 and enlarged washers 1618. Second and third lightweight composite panels 1610b, 1610c are fastened to the ends of the wall frame 1602 using screws and enlarged washers (not shown) so that the wall frame 1602 is enclosed by lightweight composite panels and the OSB sheathing 1606 on all four sides. The enlarged washers 1618 have penetrating prongs (not shown) embedded in the lightweight composite panels 1610 to prevent rotation of the washers 1618, increase gripping force, and limit how far the enlarged washers 1618 can be driven into the lightweight composite panels. The enlarged washers 1618 and penetrating prongs prevent the screws 1616 from breaking through, while allowing slight compression of, the exterior fiber mesh reinforced cementitious (or other protective) layer of the lightweight composite panels 1610 to prevent damage thereto while ensuring good fixation of the panels 1610 to the wall frame 1602.
The complete wall structure 1600 includes first and second corners at the interfaces between the first lightweight composite panel 1610a and the second and third lightweight composite panels 1610b, 1610c positioned at 90° angles. The first corner is illustrated as being tied together and protected by a rigid or semi-rigid corner bend 1614a, which can be made of metal or polymer, such as polyvinyl chloride (PVC), and a first corner layer of seam coat 1625a (e.g., thin set mortar or fine-sanded stucco) in which the corner bend 1614a is embedded. The second corner is illustrated as being tied together and protected by a strip of fiber mesh 1614b and a second corner layer of seam coat 1625b in which the fiber mesh fiber mesh 1614b is embedded. It will be understood that the corner bend 1614a and fiber mesh 1614b are alternative embodiments and need not be included in the same wall structure. Rather, some embodiments may use the fiber mesh 1614b (e.g., for simplicity and cost) and other embodiments may use the corner bend corner bend 1614a (e.g., to provide greater protection against mechanical damage caused by blunt force to the corners). The same or different material used for the seam coat 1625 can be applied over the screws 1616 and enlarged washers 1618 to form a smooth surface over which a stucco finish 1626 can be applied. The stucco finish 1626 (cement- or acrylic-based) is applied over exterior-facing fiber mesh reinforced cementitious (or other protective) layers of the first, second, and third lightweight composite panels 1610a, 1610b, 1610c and the seam coats 1625. A primer is typically not required when using acrylic-based stucco, although one can be used if desired.
A lightweight composite panel 1610 is attached to the wooden studs 1604 on a second side of the wall frame 1602 opposite the first side by screws (not shown) and enlarged washers (not shown). The enlarged washers can have penetrating prongs (not shown) embedded in the lightweight composite panel 1610 to prevent rotation of the washers, increase gripping force, and limit how far the enlarged washers can be driven into the lightweight composite panel 1610. The enlarged washers and penetrating prongs prevent the screws from breaking through, while allowing slight compression of, the exterior fiber mesh reinforced cementitious layer of the lightweight composite panel 1610 to prevent damage thereto while ensuring good fixation of the panel 1610 to the wall frame 1602.
A pair of lightweight composite panels 1610a, 1610b having first and second polymer or plaster show layers 1612a, 1612b are attached to the wooden studs 1604 on a second side of the wall frame 1602 opposite the first side by screws 1616. The lightweight composite panels 1610a, 1610b are connected together by a strip of fiber mesh tape 1620, which is thereafter covered with a seam coat 1622, which can be a skim coat of joint compound or plaster to form a smooth surface over which one or more layers of paint 1626 are applied. The joint compound or plaster can also cover any other exposed screws 1616 and screw holes in the lightweight composite drywall boards 1610a, 1610b to form a smooth surface over which the one or more layers of paint 1626 are applied.
The example stucco system 1700 of the disclosure includes a lightweight composite panel 1720, which includes an exterior-facing fiber mesh reinforced cementitious (or other protective) layer 1722 as a bonding substrate. The lightweight composite panel 1720 is fastened to the OSB panel 1710 by screws 1724. Two of the screws 1724 are shown covered by patches of a seam coat (e.g., thin set mortar or fine-sanded stucco) 1726 to create a smooth surface (although it is understood that all screws or other fasteners can be covered with the seam coat 1726). A stucco finish 1728 is applied over the fiber mesh reinforced cementitious (or other protective) layer 1722 and patches of seam coat 1726. Both cement-based stucco and acrylic stucco can readily adhere directly to the fiber mesh reinforced cementitious (or other protective) layer 1722 and seam coat 1726.
The traditional stucco system 1750, by comparison, includes a layer of black backing paper 1752 for additional moisture protection applied over the waterproof polymer membrane 1712. The black backing paper 1752 can be attached to the OSB panel 1710 by means of staples or nails (not shown). Wire lath 1754 is applied over the black backing paper 1752 and fastened to the OSB panel 1710 by nails or screws 1756. A scratch coat 1758 made from sand, cement, water, and optional components is applied over the wire lath 1754 using a trowel or sprayer. The wire lath 1754 is embedded within the scratch coat 1758 to mechanically retain the scratch coat 1758 against the black backing paper 1752 (as there is no bond-physical or chemical-between the scratch coat 1758 and black backing paper 1752. A scarifier tool is used to form horizontal ridges and troughs in the scratch coat 1758 while the scratch coat 1758 is in a plastic state. After the scratch coat 1758 has hardened, typically after at least one day, a brown coat 1760 made from sand, cement, water, and optional components is applied over the scratch coat 1758 using a trowel or sprayer to form a smooth surface. The horizontal ridges and troughs in the scratch coat 1758 create a good mechanical bond between the brown coat 1760 and the scratch coat 1758. Finally, after the brown coat 1760 has hardened, typically after at least one day, a stucco finish 1762 is applied over the brown coat 1760. Cement-based stucco can adhere directly to the brown coat 1760. In the case where the stucco layer 1728 is acrylic-based stucco, a primer (not shown) is typically applied over the brown coat 1760 to improve adhesion. Ultimately, the only thing holding the entirety of the traditional stucco system 1750 to the OSB panels 1710 are the nails or screws 1756.
In some embodiments, the OSB panel 1810 can be covered with a lightweight composite panel with factory applied drainage layer, such as what is described relative to
The second and third lightweight composite panels 1908b, 1908c are positioned at 90° angles relative to the first lightweight composite panel 1908a to form first and second corners. The first corner is protected by fiber mesh 1912 shown partially embedded in a first corner layer of seam coat 1918 (e.g., thin set mortar or fine-sanded stucco). The second corner is protected by a rigid or semi-rigid corner bend 1914 attached by screws (FIG. 19B), which can be made of metal or polymer, such as polyvinyl chloride (PVC), and shown partially embedded in a second corner layer of seam coat 1918. It will be understood that the fiber mesh 1912 and corner bend 1914 are alternative embodiments and need not be included in the same embodiment. Rather, some embodiments may use the fiber mesh 1912 (e.g., for simplicity and cost) and other embodiments may use the corner bend 1914 for both corners (e.g., to provide greater protection against mechanical damage caused by blunt force to the wall corners). One or more layers of stucco finish 1920 (cement- or acrylic-based) is applied over the exterior-facing fiber mesh reinforced cementitious (or other protective) layer 1916, patches of seam coat 1918, and first and second corner layers of seam coat 1918. A primer is typically not required when using acrylic-based stucco, although one can be used if desired.
The example stucco system 1900 also includes third and fourth lightweight composite panels 1908c, 1908d fastened to the wall frame 1902 and positioned at 90° angles relative to the first and second lightweight composite panels 1908a, 1908b to form first and second corners. The first corner is protected by fiber mesh 1916 and a first corner layer of seam coat 1918 (e.g., thin set mortar or fine-sanded stucco) in which the fiber mesh 1916 is embedded. The second corner is protected by a rigid metal corner bend 1914, which can be made of galvanized steel, and a second corner layer of seam coat 1918 covering the metal corner bend 1914. It will be understood that the fiber mesh 1916 and metal corner bend 1914 are alternative embodiments and need not be included in the same embodiment. Rather, some embodiments may use the fiber mesh 1916 (e.g., for simplicity and cost) and other embodiments may use the metal corner bend 1914 (e.g., to provide greater protection against mechanical damage caused by blunt force to wall corners). One or more layers of stucco finish 1920 (cement- or acrylic-based) is applied over the exterior-facing fiber mesh reinforced cementitious (or other protective) layers of the lightweight composite panels 1908 and patches of seam coat 1918.
In some embodiments, the screws or other fasteners used to attach lightweight composite panels to a wall frame include corresponding washers or enlarged heads that are at least about 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, or 80 mm, in diameter. This ensures sufficiently large surface contact between the screws or other fasteners and the fiber mesh reinforced cementitious (or other protective) layer so that the screws or other fasteners have a much lower tendency to tear through the lightweight composite panels or otherwise compromise the structural integrity of the wall structure formed by the lightweight composite panels.
To illustrate this point,
Reference is made to
The penetrating prongs 2410 are designed to penetrate through and become embedded within a lightweight composite panel 2420, including though the exterior fiber mesh reinforced cementitious (or other protective) layer 2422, at least partially through the foam core 2424, and optionally through the interior fiber mesh reinforced cementitious (or other protective) layer 2426 and optional drainage layer (not shown) to make abutment with a stud 2450 or other structural element of a wall frame. The penetrating prongs 2410 help retain the specialized washer 2404 in a desired position relative to the lightweight composite panel 2420 and prevent rotation while the screw 2402 is being driven through the lightweight composite panel 2420 and into the underlying stud 2450 or other structural element of a wall frame. The penetrating prongs 2410 can also provide a load spreading/pressure spreading effect to distribute normal and lateral pressure from the screw 2402 and washer body 2406 to the prongs 2410. The specialized washer 2404 and penetrating prongs 2410 provide greater lateral tension of the screw and washer assembly 2400 relative to the lightweight composite building panel 2420, thereby increasing the overall strength, including shear strength, of the wall structure.
The length of the penetrating prongs 2410 can be selected to determine and limit how far the concave interior portion 2408 of the washer body 2406 is able to advance into and compress the lightweight composite panel 2420, forming a depression therein. The penetrating prongs 2410 can advantageously have a length in order to penetrate all the way through the lightweight composite panel 2420 and make contact with the stud 2450 or other structural element. In this way the penetrating prongs 2410 can act as a stop that limits how far the specialized washer 2404 can be driven toward and into the lightweight composite panel 2420. Providing a stop prevents the specialized washer 2404 from being driven too far into the lightweight composite panel 2420, thereby preserving the structural integrity and strength of the exterior fiber mesh reinforced cementitious (or other protective) layer 2422 adjacent to the specialized washer 2404. This preserves and maximizes the overall strength, including shear strength, of the wall structure.
In some embodiments, it may be desirable for the length of the penetrating prongs 2410 to be slightly less than the cross-sectional thickness of the lightweight composite panel 2420 in order to superficially compress, but not damage, the exterior fiber mesh reinforced cementitious (or other protective) layer 2422 toward the foam core 2424 to thereby increase the compressive force of the washer 2404 bearing against the lightweight composite panel 2420. This can increase the overall fixation strength of the fastening assembly 2400.
In the case where studs or other structural elements are wood so as to permit some degree of penetration by the penetrating prongs 2410, the length of the penetrating prongs 2410 can equal or slightly exceed the cross-sectional thickness of the lightweight composite panel 2400. In such case, the penetrating prongs 2410 can be allowed to penetrate and bite slightly into the wooden studs or other structural elements while still acting as a stop that prevents excessive penetration into the lightweight composite panels 2400 and avoiding damage to the exterior fiber mesh reinforced cementitious (or other protective) layer 2405. Penetration of the penetrating prongs 2410 into wooden studs or other structural elements of a wall frame can provide additional lateral fixation between the lightweight composite panels 2400 and the wall frame. This can further help tie adjacent lightweight composite panels 2400 together and increase the shear strength of the wall structure.
In some embodiments, sealing one or more joints or seams between adjacent lightweight composite panels includes applying waterproof tape, metal flashing, polyurethane foam, fiber mesh tape and an appropriate seam coat (e.g., thin set mortar or fine sanded stucco), or other sealing means known in the over the joints or seams, including joints or seams in the wall face and corners. In addition, joints, seams, openings, or gaps between lightweight composite panels and other structural elements, such as wooden or metal beams or posts, vent pipes in roofs, fixtures, and the like, can be filled using sealing means known in the art, such as polyurethane foam, metal flashing, or tar.
In some embodiments, an appropriate seam coat can be applied over at least a portion of the exterior facing fiber mesh reinforced cementitious (or other protective) layer, including over any exposed screws, washers, or other mechanical fasteners used to attach the lightweight composite panels to the exterior wall structure, and over any joints or seams, fiber mesh tape, polyurethane, or other exposed sealants on or in the exterior wall structure.
Additional Terms & DefinitionsWhile certain embodiments of the present disclosure have been described in detail, with reference to specific configurations, parameters, components, elements, etcetera, the descriptions are illustrative and are not to be construed as limiting the scope of the claimed invention.
Furthermore, it should be understood that for any given element of component of a described embodiment, any of the possible alternatives listed for that element or component may generally be used individually or in combination with one another, unless implicitly or explicitly stated otherwise.
In addition, unless otherwise indicated, numbers expressing quantities, constituents, distances, or other measurements used in the specification and claims are to be understood as optionally being modified by the term “about” or its synonyms. When the terms “about,” “approximately,” “substantially,” or the like are used in conjunction with a stated amount, value, or condition, it may be taken to mean an amount, value or condition that deviates by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01% of the stated amount, value, or condition. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Any headings and subheadings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims.
It will also be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” do not exclude plural referents unless the context clearly dictates otherwise. Thus, for example, an embodiment referencing a singular referent (e.g., “widget”) may also include two or more such referents.
It will also be appreciated that embodiments described herein may also include properties and/or features (e.g., ingredients, components, members, elements, parts, and/or portions) described in one or more separate embodiments and are not necessarily limited strictly to the features expressly described for that particular embodiment. Accordingly, the various features of a given embodiment can be combined with and/or incorporated into other embodiments of the present disclosure. Thus, disclosure of certain features relative to a specific embodiment of the present disclosure should not be construed as limiting application or inclusion of said features to the specific embodiment. Rather, it will be appreciated that other embodiments can also include such features.
Claims
1. A method of constructing a wall structure, comprising:
- forming or providing a wall frame, the wall frame comprising a plurality of studs or other structural elements and optional sheathing forming at least one side of the wall frame;
- fastening a first plurality of lightweight composite panels to a first side of the wall frame to form a first wall substructure; and
- fastening a second plurality of lightweight composite panels to a second side of the wall frame opposite the first side to form a second wall substructure opposite the first wall substructure,
- the lightweight composite panels each comprising: a foam core having a first surface and a second surface opposite the first surface; a first protective layer selected from a first fiber reinforced cementitious layer, thermoset polymer layer, or magnesium oxide layer formed over and covering at least a portion of the first surface of the foam core; and a second protective layer selected from a second fiber reinforced cementitious layer, thermoset polymer layer, or magnesium oxide layer formed over and covering at least a portion of the second surface of the foam core, wherein the lightweight composite panels are positioned so that one protective layer faces toward and another protective layer faces away from the wall frame.
2. The method of claim 1, wherein the wall frame comprises at least one of wooden studs or metal studs.
3. The method of claim 2, wherein the wall frame omits the sheathing, the method comprising fastening the first and second plurality of lightweight composite panels to the wooden studs or metal studs forming the wall frame.
4. The method of claim 1, wherein the wall frame comprises the sheathing fastened to the studs and forming at least one of the first or second sides of the wall frame, and wherein at least some of the first or second plurality of lightweight composite panels are fastened to the sheathing.
5. The method of claim 4, wherein the sheathing comprises at least one of plywood panels or oriented strand board (OSB) panels, the method further comprising positioning at least one of a waterproofing membrane or a drainage layer between the sheathing and the lightweight composite panels fastened to the sheathing.
6. The method of claim 1, wherein the first wall substructure comprises an interior wall of the wall structure, wherein the first plurality of lightweight composite panels forming the first wall substructure include at least one of (i) a show surface selected from a polymer, plaster, or paper layer on the protective layer facing away from the wall frame or (ii) a textured surface that provides a substrate for direct application of a kitchen or bathroom finish.
7. The method of claim 1, wherein the second wall substructure comprises a second interior wall of the wall structure, and wherein the second plurality of lightweight composite panels forming the second wall substructure include at least one of (i) a show surface selected from a polymer, plaster, or paper layer on the protective layer facing away from the wall frame or (ii) a textured surface that provides a substrate for direct application of a kitchen or bathroom finish.
8. The method of claim 1, wherein the second wall substructure comprises an exterior wall of the wall structure, the method comprising fastening the second plurality of lightweight composite panels to at least one of the studs or other structural elements or sheathing forming the second side of the wall frame.
9. The method of claim 8, wherein the sheathing is included and comprises at least one of OSB panels or an underlying layer of lightweight composite panels, the method comprising applying a waterproof membrane over OSB panels when included or applying sealing tape to seal joints or seams between adjacent lightweight composite panels of the underlying layer when included.
10. The method of claim 8, wherein the second plurality of lightweight composite panels include a finish applied thereto selected from stucco, brick veneers, stone veneers, masonry, tiles, and other exterior finishes.
11. The method of claim 8, wherein the first and second wall substructure comprise first and second exterior walls of the wall structure, and wherein the first and second plurality of lightweight composite panels include a finish applied thereto selected from stucco, brick veneers, stone veneers, masonry, tiles, and other exterior finishes.
12. The method of claim 11, wherein the wall structure is selected from a fence, sound barrier, carport wall, or dumpster enclosure.
13. The method of claim 1, wherein the first and second lightweight composite panels are fastened to studs and/or optional sheathing of the wall frame by at least one of screws, other mechanical fasteners, or an adhesive.
14. The method of claim 13, wherein the screws or other mechanical fasteners include corresponding washers or enlarged heads that are at least about 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 m, 65 cm, 70 cm, 75 mm, or 80 mm, in diameter to prevent penetration of and damage to the exterior fiber mesh reinforced cementitious (or other protective) layer of the lightweight composited panels.
15. The method of claim 14, wherein the washers further include a plurality of penetrating prongs configured to penetrate at least partially through the corresponding lightweight composited panel, including through the exterior fiber mesh reinforced cementitious or other protective layer and at least partially through the foam core, optionally where the penetrating prongs penetrate all the way through the lightweight composite panel and make abutment with studs or sheathing of the wall frame.
16. The method of claim 1, further comprising applying a seam coat over exposed screws or other mechanical fasteners and over joints or seams between adjacent lightweight composite panels, followed by applying a finish over the seam coat.
17. A wall structure formed according to the method of claim 1.
18. A method of constructing a wall structure, comprising:
- forming or providing a wall frame, the wall frame comprising a plurality of studs or other structural elements and optionally sheathing forming at least one side of the wall frame;
- fastening a plurality of interior lightweight composite panels to a first side of the wall frame to form an interior wall substructure; and
- fastening a plurality of exterior lightweight composite panels to a second side of the wall frame opposite the first side to form an exterior wall substructure opposite the interior wall substructure,
- the lightweight composite panels each comprising: a foam core having a first surface and a second surface opposite the first surface; a first protective layer selected from a first fiber reinforced cementitious layer, thermoset polymer layer, or magnesium oxide layer formed over and covering at least a portion of the first surface of the foam core; and a second protective layer selected from a second fiber reinforced cementitious layer, thermoset polymer layer, or magnesium oxide layer formed over and covering at least a portion of the second surface of the foam core, wherein the interior and exterior lightweight composite panels are each positioned so that one protective layer faces toward and another protective layer faces away from the wall frame.
19. The method of claim 18, wherein the wall frame comprises at least one of wooden studs or metal studs and sheathing forming an exterior side of the wall frame, and wherein the plurality of interior lightweight composite panels are fastened to the wooden and/or metal studs and the plurality of exterior lightweight composite panels are fastened to the sheathing.
20. A method of constructing an interior wall structure, comprising:
- forming or providing a wall frame, the wall frame comprising a plurality of studs or other structural elements and optionally sheathing forming at least one side of the wall frame;
- fastening a first plurality of lightweight composite panels to a first side of the wall frame to form a first interior wall substructure; and
- fastening a second plurality of lightweight composite panels to a second side of the wall frame opposite the first side to form a second interior wall substructure opposite the first interior wall substructure,
- the lightweight composite panels each comprising: a foam core having a first surface and a second surface opposite the first surface; a first protective layer selected from a first fiber reinforced cementitious layer, thermoset polymer layer, or magnesium oxide layer formed over and covering at least a portion of the first surface of the foam core; and a second protective layer selected from a second fiber reinforced cementitious layer, thermoset polymer layer, or magnesium oxide layer formed over and covering at least a portion of the second surface of the foam core, wherein the lightweight composite panels are positioned so that one protective layer faces toward and another protective layer faces away from the wall frame.
Type: Application
Filed: Nov 13, 2025
Publication Date: Jun 4, 2026
Inventors: Zhongsheng CHEN (Draper, UT), Brian DUNN (Draper, UT), Alex GILLESPIE (Draper, UT)
Application Number: 19/388,771
