Exterior wall
This invention relates to a building exterior wall, and particularly to a rigid, laminated insulating board with an exterior stucco coating adhered thereover. 
     BACKGROUND OF THE INVENTION 
     The exterior walls of buildings have been constructed using a relatively high density rigid sheathing board affixed to the vertical studs, a low density plastic foam insulation board affixed to the outer face of the sheathing board, and an exterior stucco layer formed in place on the outer surface of the foam board. 
     SUMMARY OF THE INVENTION 
     The present invention provides an equivalent wall and, in several respects, a more advantageous wall, constructed using a single board layer and an exterior stucco layer formed in place on the outer surface of the single board layer. The single board layer consists of board which has a plastic foam core and thin rigid facings of fiber reinforced set hydraulic cement. 
     It is an object of the invention to provide an improved exterior building wall construction. 
     It is a further object to provide a more economical exterior building wall construction. 
     It is a still further object to provide an exterior building wall construction having a completely unified, highly weather-resistant, relatively lightweight, thin, but very effective structure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and advantages of the invention will be more readily understood when considered in relation to the preferred embodiments, as set forth in the specification and shown in the drawings in which: 
     FIG. 1 is a front view of a wall in progressive degrees of completion, embodying the present invention. 
     FIG. 2 is a cross-sectional plan view of the wall of FIG. 1 taken on line 2--2. 
     FIG. 3 is an enlarged portion of the cross-sectional plan view of FIG. 2. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1 there is shown the outer side of a vertical exterior building wall 10 in various degrees of completion, the portion to the right being completed wall. The wall 10 includes a plurality of vertical steel studs 12 which have gypsum wallboard 14 affixed thereto on the inner surface. 
     On the outer surface 16, of each stud 12, there is affixed rigidized, laminated, concrete faced plastic foam panels 18. Each panel 18 is attached to the surfaces 16 of studs 12 by a plurality of screws 20. Each panel consists essentially of a 1&#34;×4&#39;×8&#39; polystyrene bead board core 22, of about 1 to 3 lbs/cu. ft. density, to which has been laminated a portland cement facing 24 which contains within it a thin fiberglass mesh 26. The fiberglass mesh 26 is approximately 0.012 inch thick, with about six coated fiberglass strands per inch extending in each of the lateral direction and the longitudinal direction of the mesh 26. The portland cement facing 24 is about 0.016 inch thick, just sufficient to substantially conceal the mesh 26 disposed therewithin. The bead board core could, alternatively, be any thickness from about 178 &#34; to 3&#34; . 
     On the exterior surface of the panels 18, narrow strips 28 of fiberglass mesh, similar to mesh 26, about two inches wide, are adhered over the joints 30 between adjacent panels 18. The mesh strips 28 are adhered over the joints 30 with a thin coat of portland cement taping composition 32, such as the composition used for forming the portland cement facing 24 on panels 18. The taping composition does not need to be any thicker than the 0.012 inch thickness of the mesh strips 28. 
     As soon as the taping composition 32 has taken an initial set, the entire exterior surface of panels 18 is coated with a 1/32 inch thick portland cement exterior coating 34, similar to the composition used to forming the portland cement facing 24 on panels 18. Coating 34 could, alternatively, be applied in thicknesses up to about 1/4&#34;, using a plurality of coating steps. The surface 36 of the exterior coating 34 will preferably have a slight texture, which will form the building exterior surface. 
     The portland cement composition used for the panel facing 24, the taping composition 32 and the exterior coating 34 is of a formula approximately as follows: 
     
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                 Pounds                                                   
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Pre-Mix:                                                                  
Sand               72                                                     
Acrylic Latex Emulsion                                                    
                   15                                                     
(50% solids)                                                              
Thickener          0.5                                                    
Defoamer           0.25                                                   
Ammonia            0.1                                                    
Preservative       0.02                                                   
Water              13                                                     
Portland Cement    100                                                    
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     The portland cement is a standard Type I portland cement, except that in the exterior coating 34, a white portland cement may be substituted for the standard Type I portland cement. The acrylic latex emulsion may be Rohm &amp; Haas latex E-330 or Rhoplex AC-64. 
     Preferably, the ingredients are mixed a day or two in advance of use, with the exception of the portland cement. Just prior to use, the portland cement is combined with the premixed material at about a 1:1 ratio. As the portland cement is added to the pre-mix, or as the two are being thoroughly mixed, additional water may be needed to obtain a consistency suitable for whatever application technique is to be used with the thoroughly mixed material. 
     Various methods may be employed in applying the portland cement facing 24, the taping composition 32 and the portland cement exterior coating 34. In applying the portland cement facing 24 and the taping composition 32 care must be taken to avoid wrinkling or displacing the fiberglass mesh 26 or the fiberglass mesh strips 28, respectively. 
     The facing 24 can be applied by spray application or by a roller application, either being preferably followed by a light screeding to improve the bond of the facing 24 to the bead board core 22. The fiberglass mesh stips 28 can be held by hand for a moment as an initial area is coated with taping composition 32 on a 4&#34; broad knife, followed by continued application of the taping composition 32 with the same 4&#34; broad knife. 
     The exterior coating 34 can be applied by spraying, roller coating or troweling. A substantially uniform coating is obtained by measuring the material prepared so that about 1/2 lb/sq ft is applied uniformly over the entire exterior of the panels 18. 
     Having completed a detailed disclosure of the preferred embodiments of my invention so that those skilled in the art may practice the same, I contemplate that variations may be made without departing from the essence of the invention or the scope of the appended claims.