Patent Publication Number: US-6698144-B1

Title: Stucco casing bead

Description:
The present invention relates to an improved casing bead for the installation of exterior curtain wall or stucco siding and the like and more particularly to such a casing bead that incorporates an attached mesh structure for more secure installation and application of over-applied stucco finishes. 
     BACKGROUND OF THE INVENTION 
     The term curtain wall refers to a type of building construction in which an exterior non-load-bearing wall is supported in front of the structural frame like a curtain. U.S. Pat. No. 5,937,600 describes a casing bead or starter track for the installation of stucco-covered, curtain wall type, foamed siding applied to the exterior of buildings prior to the application of an over-applied coating of a stucco finish or the like. The device described in this patent comprises a generally U-shaped channel and incorporates in its front wall apertures for the infiltration of caulk, stucco or the like during erection and in its rear wall striations that serve to grip an inserted foam panel and any included caulking or the like. 
     While the casing bead as just described offers enhanced resistance to moisture infiltration as well as security of installation, there remains a continuing desire to improve the adhesion of the over-applied stucco finish to the casing or starter bead as described in this U.S. Patent. Thus, while infiltration of the over-applied stucco into the apertures in the front wall of the prior art casing bead channel provides some adhesion of the over-applied stucco finish, it would be highly desirable if some means could be provided to further improve the adhesion of the over-applied stucco finish to the casing or starter bead to improve the overall quality and durability of the installation. 
     OBJECT OF THE INVENTION 
     It is therefore an object of the present invention to provide an improved casing bead for installation on buildings utilizing a stucco-covered, curtain wall-type construction that demonstrates provides a mechanism for improving the adhesion of an over-applied stucco finish or the like. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an improved casing or starter bead structure for the installation of curtain wall structures of the type described above. This improved casing or starter bead incorporates a mesh attached to at least the front wall of the casing or starter bead, which mesh extends beyond the height of the front wall and provides additional area for the infiltration of over-applied stucco finishes or the like. Such additional infiltration, after drying of the over-applied layer provides a more adherent, higher quality and more durable attachment of the stucco finish to the casing bead and the overall wall structure. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partially cutaway perspective view of the improved casing bead of the present invention. 
     FIG. 2 is a cross-sectional view of the stucco casing bead of the present invention showing the relationship between the wall, the inserted foam, the over-applied stucco finish and the casing bead of the present invention. 
    
    
     DETAILED DESCRIPTION 
     As shown in FIG. 1, the casing bead  10  of the present invention comprises a relatively horizontal base  12 , an elongated upright nailing flange  14  extending vertically from upper surface  13  of horizontal base  12  at an angle of b  90 ° or more and preferably about 95°, an upright elongated front flange  16  extending upward generally parallel to nailing flange  14  and a mesh  18 , incorporating openings  28 , that is attached to the front or outer surface  19  of front flange  16 . Upright front flange  16  preferably incorporates apertures  17  that permit infiltration of an over-applied stucco or similar finish as seen most clearly in FIG. 2 described below. According to a preferred embodiment, mesh  18  is wrapped about the outside surfaces  21  and  21 A of horizontal base  12  and upright nailing flange  14  respectively. Other arrangements such as simple attachment solely to outside surface  19  of front flange  16 , or attachment to front flange outside surface  19  and base lower surface  21  are also considered acceptable as long as secure attachment of mesh  18  to the structural member(s) of casing bead  10  is achieved. Nailing flange  14  incorporates apertures  15  for insertion of fasteners such as nails  23  to attach casing bead  10  to a wall  22  (see FIG.  2 ). 
     Mesh  18  may be fabricated from any suitable material such as a polymeric filament, fiberglass etc. or any other suitable material which can be made to adhere or otherwise be attached to the structural surfaces (outside surfaces  19 ,  21  and  21 A) of casing bead  10  to allow secure attachment of stucco or other suitable finish  26  thereto through infiltration of finish  26  through openings  28 . According to a specifically preferred embodiment, mesh  18  is fabricated from fiberglass for reasons of cost, availability and strength relative thereto. 
     The size of openings  28  in mesh  18  is not particularly critical to the successful practice of the present invention, as long as openings  28  are of a size and configuration as to provide adequate improved adhesion of over-applied finish  26  as described herein. A preferred size for openings  28  is about one eighth inch square as this size is easily obtained and provides the required adhesion of finish  26  to curtain wall casing bead  10 . 
     Mesh  18  may be attached to casing bead  10  in any suitable fashion including but not limited to adhesion using an appropriate adhesive, double sided tape, strippable adhesive tape or using more sophisticated techniques such as welding, ultrasonically or otherwise, of mesh  18  to outside surfaces  19 ,  21  and  21 A. Whatever method is used to attach mesh  18  to the structure of casing bead  10 , it should be adequate to provide a relatively strong attachment to provide the enhanced bonding quality and durability desired through the use of this unique and novel structure in a curtain wall installation. 
     Casing bead  10  may be fabricated from any suitable material such as a metal or plastic, however plastic materials such as poly(vinyl)chloride and the like are specifically preferred for reasons of cost and ease of manufacture through extrusion. 
     FIG. 2 shows casing bead  10  applied to a wall  22  using nails or similar fasteners  23  and including mesh  18 , an inserted foamed panel  24  and over-applied stucco or similar finish  26 . Apertures  17  allow infiltration of stucco or similar finish  26  into upright front wall  16 . Similarly, stucco or similar finish  26  infiltrates the openings  28  in mesh  18  allowing stucco or similar finish.  26  to adhere to foam panel  24  through the various apertures  17  and openings  28  to firmly secure stucco finish  26  to foam panel  24  and in turn to casing bead  10  after finish  26  sets or hardens, thereby providing a virtually monolithic or at least unitized curtain wall structure. 
     While it is preferred that mesh  18  be co-extensive, i.e. extend along the entire length of front flange  16 , it is, of course, possible to obtain some of the advantages of the use of the structure described herein by locating segments of mesh  18  intermittently along front flange  16 , at either end of a section front flange  16  or in any other of numerous possible configurations, and all of such alternative configurations are considered to be within the scope of the preferred embodiments of the present invention. 
     In the prior art casing beads of the type described herein, nailing flange  14  has been relatively short, i.e. less than about 2 inches. This made nailing of the casing bead in place relatively difficult and, while providing adequate protection against moisture permeation due to “blow back” of rain at the junction of the casing bead and the over-applied stucco, in some more aggravated cases, moisture could and did pass over the top of the nailing flange. The casing bead  10  of the present invention utilizes a nailing flange  14  that is between about 3 and 4 inches high and preferably at least 3.5 inches high to simplify the nailing task and to provide added protection against moisture penetration in high wind situations. 
     Base  12  may be of any appropriate width, but should be such as to engage the foam panel  24  being installed therein. Such materials generally have a thickness of between about ½ of an inch and 1 inch and the width of base  12  between nailing flange  14  and upright front flange  16  should be such as to accommodate such materials of these dimensions. 
     As will be apparent to the skilled artisan, a number of variations and modifications can be made to the structure described above without departing from the spirit and scope of the present invention. All sucb modifications and variations are clearly contemplated as being within the scope of the appended claims.