US 20060005489 A1
A drywall finishing system for finishing 1) normal inside and outside corners of any angle, 2) stub wall or closet corners, 3) window wrap corners, and 4) L-metal for window sills and areas where drywall ends against some other surface like brick. The finishing system comprises a preformed trim piece comprising a semi-rigid member that is relatively thick in the center and tapers laterally to a thin edge. A layer of paper is bonded to the inside surface of the semi-rigid member for receiving joint compound to continuously bond the trim piece to the dry wall; this paper layer can optionally have a layer of adhesive material on its outer surface. A layer of finishing material is bonded to the exterior surface of the semi-rigid member.
1. A flexible trim piece comprising, in combination:
an elongated, semi-rigid member with first and second surfaces, said first surface divided into a left part and a right part by a longitudinal groove running end-to-end, said groove forming a hinge whereby said member can be flexed about said hinge to produce a selected angle between said left part and said right part;
thin strips of covering material bonded to each of said left and right parts respectively of the first surface of said semi-rigid member, said strips running the length of said semi-rigid member, each of said strips having a layer of adhesive material on an outer surface; and
a thin layer of finishing material on the second surface of said semi-rigid member, said layer running the length of said semi-rigid member, substantially the entire second surface of said semi-rigid member being continuously bonded to said finishing material layer, said finishing material layer adapted to directly receive paint or texture.
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This application is a continuation of co-pending application Ser. No. 10/200,478 filed Jul. 20, 2002, which was a continuation of application Ser. No. 09/715,614 filed Nov. 17, 2002, now abandoned, which was a continuation of application Ser. No. 09/191,861 filed Nov. 12, 1998, now U.S. Pat. No. 6,148,573. Application Ser. No. 09,191,861 was a continuation-in-part of application Ser. No. 08/832,470 filed Apr. 2, 1997, now abandoned, and was also a continuation-in-part of application Ser. No. 08/718,137 filed Sep. 18, 1996, now abandoned. Both application Ser. Nos. 08/832,470 and 08/718,137 were continuations-in-part of a single parent application Ser. No. 08/544,339 filed Oct. 17, 1995, now abandoned.
1. Field of the Invention
This invention relates generally to the field drywall construction and more particularly to a system of exterior and interior drywall seams and corners that greatly reduces the amount of time, labor and material required to finish a modern structure.
2. Description of Related Art
The use of gypsum drywall board in modern construction is well known. Manufactured drywall sheets are nailed to studs to form interior walls and ceilings. Before these sheets can be painted or textured, the joints must be taped and sealed with joint sealing compound (drywall mud). Drywall tape is a porous fibrous material, usually paper, which is designed to permanently bond with drywall mud.
Taping also (known as stringing) is a tedious process. First, mud and tape must be applied by hand or dispensed with a tool known as a bazooka. The worker rolls and glazes the tape while the mud is wet. As the tape strings out, it has a tendency to pull in the direction of motion. After the tape is applied, it is coated with additional mud and the edges are feathered with a wide blade drywall knife to form a smooth transition between the seam and the wall. The mud is then allowed to dry, typically overnight. Next, the seam is sanded, recoated with mud, dried and sanded again. The process is repeated if necessary until a smooth seam is produced.
Corners present a special problem. Inside corners are finished using drywall tape in much the same manner as flat joints. Outside corners are typically finished with corner beads.
Corner beads are either sharp edged or rounded nose, also known as “bullnose.” These are used on exterior corners at windows and other openings. To use a standard corner bead, it first must be cut from a standard length of 8 feet or 10 feet. The bead is nailed into position using short nails approximately every foot. The worker must: 1) keep the bead plumb or level, and 2) keep the bead at the proper angle to prevent slipping too far to one side or the other. If this latter condition occurs, a “shiner”, as it is called in the trade, results. This is where the bead is too far toward one side of the corner making the other side flange hard to coat.
Once the bead is installed, the worker must “first coat” the bead. This means to coat it with mud for the first time. This is very labor intensive, and it uses a large amount of mud. The bead projects outwardly from the corner. Accordingly, when first coat is applied a wedge of mud is formed which is thickest at the bead and tapers out to meet the wall. After the first coat, the mud is allowed to dry. Drying takes about a day.
After the “first coat” is dry throughout the building, the worker has to sand this first coat of mud and clean all the metal edges. This is especially difficult with bullnose bead. After the “first coat” is sanded, the worker proceeds to “second coat” the bead repeating the entire process again and waiting another day to dry. The worker finally must again sand the bead carefully looking for imperfections, and touching these up. At this point, the bead is ready for texture or paint. The entire process uses considerable mud, and is very labor intensive, especially the sanding. In terms of total construction time, it requires two to three days to complete all the corners of a typical residence.
An alternative to fixed corner beads, especially for corners that do not meet at 90 degrees is a product known as “flex bead.” Flex bead consists of two thin strips of metal bonded to a two inch paper tape. To use “flex bead”, a worker first spreads all-purpose mud along the wallboard on both sides of the angle. A length of “flex bead” is folded by hand to create a crease. The bead is then installed in the angle. This requires a good eye for straight lines since the “flex bead” will not make a straight line by itself. The worker must move the bead around to the best of his abilities to set it as straight as possible. On many occasions, the worker will end up with a line that is not straight; this condition is called “snaking”.
Once the “flex bead” is installed and dry, the first coat procedure is started. Most journeymen only coat one side of the angle at a time. If one tries to coat both sides at the same time, the mud flops over to the other side, and the knife digs a line into the mud on the other side of the angle. Therefore, the following process is usually used: 1) Apply a first coat of mud to one side and wait until it is dry; 2) Apply a first coat of mud to the other side and wait until it is dry; 3) Sand both sides and clean at the crease; 4) Apply a second coat of mud to one side and wait until it is dry; 5) Apply a second coat of mud to the other side and wait until it is dry; 6) Sand and touch up both sides. This process is tedious, and requires considerable time while the respective sides are drying. Accordingly, considerable drawbacks remain unsatisfied.
What is badly needed is a system for finishing drywall on the interior of buildings that avoids the difficulties of taping, corner beads and “flex bead” while retaining the perfect finished appearance that is required for texturing or painting. The sanding steps should be reduced or eliminated. This system should reduce the labor to less than one day for a typical residence and significantly reduce the amount of mud used.
The present invention relates to a drywall finishing system for finishing 1) inside and outside corners of any angle, 2) stub, end or closet walls, 3) window wrap corners, and 4) L-member for window sills and areas where a drywall ends against another surface e.g. brick. In addition, the system includes accessory products for each of the pieces mentioned.
The drywall finishing system of the invention in its most basic form is an elongated, preformed trim piece comprising a semi-rigid member having two flanges and inner and outer surfaces. The inner surface is provided with bonding means for continuously bonding the semi-rigid member to the drywall. The outer surface of the finishing member is provided with finishing means adapted to receive paint or other texture. The flanges of the semi-rigid member are tapered in a lateral direction, being thickest at the center and tapering to a thin edge.
A first preferred embodiment is a flexible trim piece, comprising a semi-ridged member having two flanges, each of the flanges being tapered to a thin lateral edge. The semi-rigid member has a longitudinal groove between the flanges forming a hinge. A covering material is bonded to the inside surface of the semi-rigid member. The covering material is preferably drywall tape for forming a good continuous bond with drywall mud between the trim piece and the drywall. A finishing material is bonded to the exterior surface of the semi-rigid member. The finishing material is preferably a fibrous material such as a paper which is suitable for directly receiving paint or other texture. The finishing material may desirably extend laterally beyond the respective side edges of the semi-rigid member forming side tabs.
To install the first embodiment of the invention, a length of preformed trim piece is selected from stock and cut to length if not exactly the right length. A flat coat of mud is applied to both sides of a drywall corner. The preformed piece is folded at the groove to match the corner, and placed over the mud and smoothed into place. Since the trim piece of the invention is preformed, the piece makes a straight line at the required angle. Once, the piece is in place, the edges are feathered or “killed” once with a small amount of mud and a wide drywall blade or knife. At that point the corner is complete except for drying. It requires little or no sanding. After the mud has dried, the finishing material can be directly textured or painted.
The present invention is placed on top of a coat of applied mud at the corner. The corner can be an exterior or interior angle. No nails are required, since the invention pieces stick to the mud. The exterior finishing material is paper, plastic, or other suitable material for receiving texture or paint. The present invention eliminates most of the intense labor associated with present methods since none of the parts need to be coated with mud or sanded. In addition, the parts form straight, finished lines and angles as soon as they are installed.
Additional embodiments of the invention include right angle outside corner trim pieces, bullnose outside corner trim pieces, stub or end wall trim pieces, U-shaped and V-shaped joint pieces, and other trim and specialty pieces.
These advantages and other advantages of the present invention will become more fully apparent from the following detailed description when read in conjunction with the accompanying drawings.
For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention.
It should be noted that many of the figures show exaggerated features such as the thickness of various members and materials. This is necessary to adequately describe and point out the features and advantages of the present invention.
Description of Prior Art
After the layer has dried, it is rough sanded. Next, a second or finish coat of mud is applied over the first coat to fill any cracks, holes or other irregularities in the first coat. The finish coat is allowed to dry. Afterwards, the finish coat is fine sanded. Occasionally a second finish coat is required, followed by another fine sanding. The process of finishing the corner may take two or three days. The time, labor and material quantities and attendant cost required to build the corner are directly proportional to the volume of mud that forms wedges F.
The primary drawbacks of the prior art are: (1) the labor and material costs necessary to build and finish the wedge of mud F between the member C and the drywall; (2) the significant time required to allow the mud to dry between applications, i.e., two to three days; and (3) the propensity for cracking along the edge of the flange E and the showing of ridge lines D. Each of these long standing problems in the prior art are solved by the product and method of the invention.
Tapering should be distinguished from the edge bevel. The object of tapering is to form an elongated preformed wedge similar in configuration to the conventional wedges of drywall mud built in situ. See reference letter F in
Accordingly, the preformed, tapered semi-rigid member replaces the labor intensive, costly operations of conventional corner beads. A bevel on the other hand is an abrupt edge cut that would not materially reduce labor or material costs.
The groove 18 separates the first surface 22 of the piece into a left half and a right half. These two halves do not have to be the same width. In fact, one of the halves can be considerably wider than the other to form an L-trim member or similar type member if desired. The first surface 22 of the semi-rigid member 12 can be covered by two strips of covering material 14 firmly bonded to the semi-rigid member 12. This covering material can be paper similar to that used on drywall, or joint tape paper, or other suitable material adapted for forming a continuous bond to drywall with mud. It should be noted that adhesive other than drywall mud could be used to attach the present invention to drywall; however, the preferred method is to use only drywall mud. Also it should be noted that the groove 18 can normally be formed during extrusion of the semi-rigid member 12; however, it is also possible to form it using a scoring tool or a set of male/female scoring tools. The preferred method is to extrude the semi-rigid member 12 and use an extrusion die to form the groove 18.
The second surface 24 of the semi-rigid member can be covered by a strip of finishing material 16 also firmly bonded to the semi-rigid member 12. The finishing material preferably extends laterally beyond the edges of the semi-rigid member forming side tabs 30. The side tabs 30 are adapted to be adhered to the drywall. The finishing material can be cup stock paper having an outer surface that can directly receive paint or texture. It can be any other material that can directly receive paint or texture without the need of sanding or mud.
Both the covering material and finishing material layers are bonded to the semi-rigid member. By bonded, what is meant is any process that firmly attaches the material to the member. Glue could be used, but it is preferable to extrude the entire piece with the semi-rigid member being high impact plastic. Here, the plastic with the groove and both paper layers are laminated together with the plastic being hot melted to the paper layers for a permanent bond. The groove 18 can be made with an extrusion die.
The first embodiment shown in
It is also possible to make the first embodiment with the semi-rigid member very thin to be extra-flexible for use primarily in interior corners with angles less than or equal to 90 degrees. This embodiment may have a constant, rather than tapered, cross section. Pieces for interior angles greater than 90 degrees must be much stronger since it has been discovered that if a flexible piece is used for such an angle, the shrinkage of the mud coupled with building movement causes the entire piece to deform and shift leading to unacceptable work.
The “Ultra-Flex” and other pieces can be supplied on rolls as well as in precut lengths. In order that long pieces of the material can be put together end-to-end, it is possible in manufacture to stamp approximately 1 inch on the back of the material on one end of the product with a half cut enabling the user to peel off the plastic and back paper (or other fibrous material) leaving only the front paper (or other fibrous material). In this way pieces can be joined end-to-end seamlessly. This aspect of the invention will be further discussed in reference to
A method of installing the first embodiment of the invention is as follows. A worker first applies drywall mud to both side walls of the corner to be finished. The pre-formed trim piece is cut to length and placed in the corner against the wet mud. The piece is positioned for final appearance and pressed into place; then, the excess mud can be wiped or rolled out, and finally the edges are “killed” by applying a small amount of finishing mud to the edges and smoothing them with a wide blade knife so that they merge into the surrounding drywall. There is no further finishing. When the mud dries, the corner is ready for painting or texturing. This represents a considerable savings in time and money over existing methods.
A second embodiment is illustrated in
The right angle corner trim piece 50 comprises an elongated semi-rigid member 52 with an interior layer of covering material 54 and an exterior layer of finishing material 56. The semi-rigid member 52 is preformed with a permanent right angle between flanges 60. The flanges are each laterally tapered from a maximum thickness at the corner 58 to a minimum thickness near lateral edges 66. Tapering can start at the corner or it can start a distance away from the corner 58.
The first or inside surface of semi-rigid member 52 is covered with two strips of covering material 54 firmly bonded to the semi-rigid member as described in reference to the first embodiment. Similarly, the second or outside surface of semi-rigid member is covered with a strip of finishing material 56 also firmly bonded to the semi-rigid member. As described in reference to the first embodiment, the finishing material extends laterally beyond the edges of the semi-rigid member forming side tabs 70.
As with the first two embodiments, strips of covering material 114 are bonded to the first or interior surface of the semi-rigid member and finishing material 116 is bonded to the second or exterior surface. The finishing material extends laterally from the semi-rigid member forming side tabs 130.
Trim piece 150 comprises an elongated semi-rigid member 152 having an interior layer of covering material 154 and an exterior layer of finishing material 156 laminated thereto. Trim piece 150 is preformed with flanges 160, and a center portion 161 between the flanges. The flanges are each laterally tapered from a maximum thickness adjacent center portion 161 to a minimum thickness near lateral edges 166. Trim piece 150 is preformed with a permanent right angle at 157 between one flange 160 and center portion 161. Running the length of the member is a groove 158 between center portion 161 and the other flange 160. The groove 158 forms a hinge so that the other flange may be rotated relative to the center portion. In addition, there can be two grooves instead of a groove and a right angle 157. The right angle 157 can be replaced by the second groove. In this case, the piece can be made flat.
The center piece 161 can be different widths (distance between the flanges 160) depending on the construction. In the case of a 3½ inch stud and two ½ sheets of drywall, the center piece would be around 4½ inches wide. In the case of the same stud with two ⅝ sheets of drywall, the width would be around 4¾ inches. Different versions of this piece can be made for typical construction situations; specialized versions can be made for any situation. The width of the flanges 160 can be between 1 inche and 12 inches, with about 2¼ inches being preferred. The thickness of the center piece 161 can be from around 20 thousands of an inch to around ½ inch to form a finished wall. This thickness is not critical to the invention, and many other thickness are possible.
While the preferred embodiments of the present invention have been shown and described, it is to be understood that various modifications and changes could be made thereto without departing from the scope of the appended claims.