Patent Application
20080196336
1. Field Of The Invention
This invention relates generally to a wall on the exterior of a habitable building, and more particularly relates to a wall made of a sheet of fiber reinforced concrete combined with a mortar applied directly to the sheet.
2. Description Of The Related Art
Most habitable buildings are made of vertical support members, such as wooden or metal studs or steel beams. The Support members, form a substructure to which sheets of sheathing material is attached. Typical sheathing includes plywood, oriented strand board (OSB) or some type of lightweight, insulating material, such as that sold under the trademark CELOTEX.
The conventional method of applying a cementitious mortar, including stucco, to the exterior surface of a building, such as a house, involves many steps. Once the sheathing is in place on the building, a tar-paper or other moisture-impermeable sheet is stapled or otherwise mounted to the exterior surface of the sheathing. The next step is the attachment of a screen or wire over the paper to the sheathing to which the mortar can attach. The screen is typically stapled or nailed to the sheathing. A common problem with attaching the screen to the sheathing is securely attaching enough fasteners to keep the screen in place. Once the screen is fastened, a mortar is troweled over the screen. If the mortar is stucco, which will form the outer surface of the building, the mortar is troweled smooth, or with a pattern that forms a decorative surface. If the mortar will form the base for a plurality of masonry units, such as stone or brick, the mortar is left rough so that the stones have a subsurface to which to attach.
The process of attaching paper, screen and mortar to the sheathing of a conventional building requires substantial skill. Mistakes by the person forming the underlying structure will permit water to infiltrate the building for many years, thereby causing cracks and large amounts of stucco or stone to fall off.
Therefore, the need exists for a method of forming an exterior of a building that requires less skill than the conventional method, and which is less susceptible to damage from lower skilled artisans.
The invention includes a method of forming an exterior wall of a habitable building having a substructure made of vertical support members. The method comprises mounting at least a first panel made of fiber-reinforced concrete to the substructure and then applying mortar on a first major surface of said first panel. In one embodiment of the invention, a plurality of modular masonry units, such as bricks, stones or tiles, are attached to the mortar and then mortar is injected between each of the masonry units.
The first fiber-reinforced concrete panel is mounted in place, in a preferred embodiment, by a plurality of fasteners driven through the first panel into the substructure. A second panel made of fiber-reinforced concrete is then mounted to the substructure above the first panel by aligning a downwardly sloped lower edge of the second panel with a downwardly sloped upper edge of the first panel. It is contemplated that the joint formed between the panels can be taped or otherwise treated to reduce the appearance or function of a seam.
The invention also contemplates an exterior wall of a habitable building. The building has a substructure made of vertical support members, and the wall comprises a first panel made of fiber-reinforced concrete mounted to the substructure and mortar mounted on a first major surface of said first panel. In a preferred embodiment, the first major surface of the first panel is a cementitious material that has a three dimensional texture.
In another embodiment of the invention, a groove is formed in a second major surface that opposes the first major surface to permit water to drain downward. This eliminates the need for tar paper that is conventionally used with lath and conventional mortar construction.
The invention permits stucco, stone, brick, tile and other masonry surfaces to be formed on buildings without the need to attach tar paper and screen to the sheathing of the building. Additionally, the finished product is mold-resistant due to the acidity inherent in it, much stronger than walls made with conventional sheathing materials, and less costly to form. The invention forms a vapor barrier and/or retardant, as well as a fire block, and can be used in areas where high winds are a problem.
In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or term similar thereto are often used. They are not limited to direct connection, but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
The materials are mixed together, sprayed into a mold and cured to form a sheet. The panel can be solid entirely through the thickness, or it can vary through its thickness. For example, it may be desirable to interpose an alkali-resistant scrim cloth between one face of the panel and the other face. The sheet can be a standard size, such as four feet wide by eight feet long, and between about one-quarter and one inch, and preferably about one-half or seven-sixteenths inches thick.
Of course, other materials can be used to make the panel 10, so long as the panel is fiber-reinforced and has a cementitious surface to which a cementitious mortar can be applied. Additionally, panels of other sizes can be made, as will be recognized by the person having ordinary skill in the art. For example, a panel can be made that is the length and width of the entire side of the building. Panels can be manufactured that have window openings already formed in the appropriate areas. Still further, panels can be made that extend around corners of the building to avoid seams at building corners. Preferably, however, the panels are planar sheets of a size that can be lifted by two average men, with a maximum weight of about 100 to 200 lbs. Although the panels are preferably four feet wide by eight feet long, they can be cut to the desired shape at the construction site, such as by circular or reciprocating saws. Of course, the panels can vary from this preferred size. For example, the sheets can be much larger, and then cut to the desired size at the construction site. The panels can be smaller, such as two feet wide by four feet long.
Once the panel is formed, it is mounted to the substructure of a building, such as a house, office building, outbuilding, commercial building, condominium or any other building that is habitable. The substructure of the typical house is made of wooden or steel Stud walls, such as those referred to as “two-by-fours”, vertically oriented to support the floor above. However, the substructure in some buildings is made of large wooden, steel or other posts or beams at corners only. The present invention can be used with any such substructure.
The panel 10 is attached to a substructure, such as the wall 20 shown in
The panel 10 is rigidly mounted to the studs 22 to provide the same or better sheathing characteristics (strength, rigidity, load-bearing, etc.) as conventional sheathing materials with the added benefit of a mold-resistant and substantially fire proof panel.
Once the panel 10 is mounted in place, a second panel 40 can be mounted above the first panel 10 as shown in
Once the panels are mounted to the substructure, a layer of cementitious mortar 50 is applied to the outwardly facing major surfaces 14 and 44 of the panels 10 and 40, respectively. The major surfaces 14 and 44 have a “three dimensional texture” formed on them that permits the mortar to strongly attach thereto. The term “three dimensional texture” refers to the major surface having multiple surface structures having a length and width in the plane of the panel, and a depth, measured perpendicular to the plane of the panel. A preferred texture is a repeating pattern, often referred to as “knurled”, that includes rows and columns of protruding bumps with grooves formed between each bump and the adjacent bumps. Alternatively, any shape can be used that enhances the strength with which the mortar attaches to the panel, such as the shape shown in
The mortar 50 attaches directly to the major surfaces 14 and 44 without the need for wires or screens to be attached to the panels 10 and 40, because the major surfaces 14 and 44 are made of a cementitious material. This permits the cementitious mortar to mount directly thereto. In one contemplated alternative embodiment, the major surface of a panel is made of a cementitious material, but another layer or other layers of the panel are made of a non-cementitious material. The cementitious mortar can be a stucco material that is shaped to an aesthetically pleasing contour and then painted, or the mortar can form a masonry base to which bricks, cultured stone, tile, marble or any other masonry unit can be attached. A “masonry unit” is defined herein to be any module that is commonly used to form a weather-resistant surface on a building exterior, and is attached by adhesive or mortar with other similar modules, which are then typically grouted in place by injecting mortar into gaps between the modules.
The step of adding the masonry units includes, referring to
In a preferred embodiment, grooves 220 and 230 are formed in a second major surface 216 of the panel 210 shown in
The panel 300 shown in
While certain preferred embodiments of the present invention have been disclosed in detail, it is to be understood that various modifications may be adopted without departing from the spirit of the invention or scope of the following claims.
