Exterior walls with stucco or other exterior wall finishes applied to lightweight composite panels

Abstract

Exterior wall structures include exterior walls and lightweight composite panels to which an exterior finish is applied. Exterior wall structures may include wooden or metal studs to which sheathing (e.g., OSB panels or composite sheathing panels) are fastened. A drainage layer can be positioned between sheathing and lightweight composite panels to which an exterior finish is applied. Lightweight composite panels are fastened to sheathing and/or studs by screws, nails, rivets, other mechanical fasteners, and/or adhesive. Lightweight composite panels can include a polymer foam core with interior and exterior surfaces and fiber mesh reinforced cementitious layers formed over and covering the foam core surfaces. Joints between adjacent lightweight composite panels can be sealed using sealing tape, mesh tape and a seam coat, polyurethane foam, and/or other sealants. The exterior wall structure is waterproof, fire-resistant, and facilitates application of different finishes, such as stucco, tiles, or stone, masonry, or brick veneers.

1 . A method of constructing an exterior wall finish, comprising:
 forming or providing an exterior wall structure of a building or enclosure;   fastening a plurality of lightweight composite panels to an exterior side of the exterior wall structure, 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 exterior wall structure of the building or enclosure; and 
   applying an exterior finish to the lightweight composite panels.   
     
     
         2 . The method of  claim 1 , wherein the exterior wall structure comprises at least one of wooden studs or metal studs and sheathing fastened to the wooden studs or metal studs. 
     
     
         3 . The method of  claim 2 , wherein the sheathing comprises the plurality of lightweight composite panels to which the exterior finish is applied. 
     
     
         4 . The method of  claim 2 , wherein the sheathing comprises a plurality of oriented strand boards and/or an underlying layer of lightweight composite panels different than the plurality of lightweight composite panels to which the exterior finish is applied. 
     
     
         5 . The method of claim  5 , further comprising at least one of a waterproofing membrane or a drainage layer positioned between the sheathing and the plurality of lightweight composite panels to which the exterior finish is applied. 
     
     
         6 . The method of  claim 1 , further comprising applying a seam coat over exposed fasteners and joints or seams between adjacent lightweight composite panels to which the exterior finish is applied, and wherein the exterior finish is applied over the seam coat. 
     
     
         7 . The method of  claim 1 , wherein the plurality of lightweight composite panels to which the exterior finish is applied are fastened to studs or sheathing of the exterior wall structure by a plurality of screws, other mechanical fasteners, and/or an adhesive. 
     
     
         8 . The method of  claim 7 , wherein the screws or other mechanical fasteners include corresponding washers, enlarged heads, pan head screws, or screws with integrated washers 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 an exterior protective layer of the lightweight composite panels. 
     
     
         9 . The method of  claim 8 , wherein the washers further include a plurality of penetrating prongs configured to penetrate at least partially through the corresponding lightweight composite panel, including through the exterior protective layer and at least partially through the foam core, such as where the penetrating prongs penetrate all the way through the lightweight composite panel and make abutment with studs or sheathing of the exterior wall structure. 
     
     
         10 . The method of  claim 1 , wherein the exterior finish comprises a stucco finish. 
     
     
         11 . The method of  claim 1 , wherein the exterior finish comprises brick veneers, stone and masonry, or tiles. 
     
     
         12 . The method of  claim 1 , wherein the foam core comprises a polymer selected from the group consisting of extruded polystyrene (XPS), expanded polystyrene (EPS), polyisocyanurate, polyurethane (PUR), phenolic polymers (e.g., phenol-formaldehyde), melamine polymers (e.g., melamine-formaldehyde), and other thermoplastic and thermoset polymers that can be formed into a rigid or semi-rigid polymer foam structure. 
     
     
         13 . The method of  claim 1 , wherein the foam core comprises an inorganic foam material selected from the group consisting of silica gel, aerogel, silicate foams, urea-silicate foams, SiOC/SiC, ceramic foams, and refractory foams. 
     
     
         14 . The method of  claim 1 , wherein at least one of the first or second fiber reinforced cementitious layers is included and comprises fiber reinforcement embedded within a hardened cementitious composition. 
     
     
         15 . The method of  claim 14 , wherein the fiber reinforcement is selected from fiber mesh, alkali-resistant fiberglass mesh, embedded fibers, fabric, woven, scrim, felt, and non-woven, wherein the fiber reinforcement comprise at least one of plant fibers, polymer fibers, and inorganic fibers, which are selected from fibers or filaments formed from glass, basalt, rock wool, or carbon. 
     
     
         16 . The method of  claim 14 , wherein the at least one of the first or second fiber reinforced cementitious layers has a cross-sectional thickness in a range of about 0.5 mm to about 3 mm, or about 0.75 mm to about 2.5 mm, or about 1 mm to about 2 mm, or about 1.25 mm to about 1.75 mm. 
     
     
         17 . The method of  claim 1 , wherein at least one of the first or second thermoset polymer layers is included and comprises polyurea or polyaspartic and is optionally fiber-reinforced. 
     
     
         18 . The method of  claim 17 , wherein the at least one of the first or second thermoset polymer layers has a cross-sectional thickness in a range of about 1 mm to about 5 mm, or about 2 mm to about 4 mm. 
     
     
         19 . An exterior wall finish of a building or enclosure constructed according to the method of  claim 1 . 
     
     
         20 . An exterior wall finish, comprising:
 an exterior wall structure of a building or enclosure;   a plurality of lightweight composite panels fastened to an exterior side of the exterior wall structure, wherein the lightweight composite panels each comprise:
 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 exterior wall structure of the building or enclosure; and 
   an exterior finish applied to the lightweight composite applies.