Joint strip, method of forming a wall using the joint strip and wall made therefrom

An improved joint strip for concealing a joint formed between two panels of adjacent wallboards formed of a flexible support strip capable of withstanding day-to-day wall vibrations and a rib adhered on one side of the support strip such that it extends the length of the support strip. The support strip may be formed from a variety of materials such as synthetic fibers, cellulose fibers, non-woven paper, plastic fibers, fiberglass, specially treated fabric, and mixtures thereof. The joint strip possesses superior strength and flexibility properties thus eliminating the need to use predecorated wallboard for forming a monolithic appearing wall.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an improved joint strip for finishing the joint 
between two panels of adjacent wallboard and to the wall formed using the 
improved joint strip. 
2. Description of the Prior Art 
Wallboard building panels are widely used in the building industry, 
including the manufactured housing industry, to form relatively 
inexpensive and durable walls. Although the dimensions can vary, the 
wallboard building panels are typically manufactured in 4'.times.8', 
4'.times.9', 4'.times.10', and 4'.times.12' sizes and are nailed, screwed, 
or otherwise secured to wall studs. Although the wallboard building panels 
may be easily secured to the wall support studs to form a wall, it is well 
known that the joints between the adjacent panels are difficult to hide or 
decorate. For example, U.S. Pat. No. 4,157,271 to Moore discloses a 
drywall filler for joining two conventional drywall building panels. The 
joint filler material is present in the shape of a tapered top strip with 
a center spline extending outwardly from the strip center. The strip is 
formed of a one-piece vinyl molded plastic member. The drywall filler is 
disadvantageous, however, in that it is incapable of being sanded to 
produce a smooth surface and that its sharp taper causes a discontinuity 
between joint filler and drywall surfaces. 
Among the efforts to conceal the joint between wallboard building panels is 
the use of predecorated panels, which often tend to emphasize the joint 
rather than create a monolithic, seamless wall. For example, U.S. Pat. No. 
3,816,199 to Dawdy et al. discloses a concealed joint for the fastening of 
a predecorated wallboard. The patent teaches pressing the edges of the 
predecorated sheet into joints formed between the panels and then 
inserting a decorative strip to hold the predecorated sheet edges in place 
in the joint. Similarly, U.S. Pat. No. 4,656,805 to Wenkowski discloses a 
paper batten for use in "concealing" the joints between predecorated 
gypsum wallboard. The batten is fabricated from predecorated wallboard 
paper with pressure-sensitive adhesive on the back thereof for securement 
over the joint. Unfortunately, the paper battens tend to wrinkle and fall 
off. Moreover, the battens when in place are still noticeable and do not 
create the appearance of a monolithic or seamless wall. 
In U.S. Pat. No. 3,708,935 to Kossuth et al. a concealed joint for the 
fastening of predecorated wallboard is disclosed. Kossuth et al., however, 
uses a tapered edge wallboard and the "mud system" for filling the channel 
between the sheets and the tapered area. However, a significant 
shortcoming is that this method requires the use of tapered edge wallboard 
and considerable skilled labor to properly finish the joints. 
Recent efforts, however, have focused on eliminating the need for skilled 
labor to form the "seamless" joints between adjacent predecorated 
wallboard building panels by pulling back edge flaps of the predecorated 
covering to expose the joint, adhering a joint strip over a groove formed 
by the adjacent wallboard panels, and positioning the wall covering edge 
flaps in an overlapping relationship. The overlapping portions of the edge 
flaps are removed, and the remaining portion of the edge flaps are adhered 
to the joint strip such that a smooth, seamless appearing joint surface is 
formed between the predecorated wallboards. One such system is set forth 
in U.S. Pat. No. 5,311,717, of which this application is a 
continuation-in-part. In this patent there is disclosed a wall formed of 
predecorated wallboard in which a groove has been cut to accommodate a 
joint strip. The joint strip is sealed in the groove and the flaps of the 
decorated wallboard are sealed over the joint strip. While that invention 
forms an attractive wall and provides benefits in reduced costs of 
manufacturing, it is limited, because of the nature of the joint strip, to 
walls formed of predecorated wallboard. 
The present invention overcomes the deficiencies of the prior art by using 
a joint strip with superior properties thereby eliminating the requirement 
to use predecorated wallboard for forming a monolithic appearing wall. 
It is therefore the general object of the present invention to provide an 
improved joint strip for finishing the joint between two sheets of 
adjacent wallboard. 
Another object of the present invention is to provide a method for making a 
monolithic appearing wall formed using the joint strip of the present 
invention. 
A further object of the present invention is to provide a monolithic 
appearing wall which eliminates the need to fill joints with joint 
compound and the substantial skilled labor requirements to properly apply 
the joint compound. 
A still further object of the present invention is to provide an improved 
joint strip which is capable of withstanding movement connected with daily 
usage such that predecorative covering is no longer necessary. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, there is provided a joint strip, 
and a method of joining wallboards to conceal the joint therebetween 
without the need for predecorated wallboard covering, joint compound, 
battens, and similar conventional techniques now in use in building 
construction. The joint is finished by attaching a joint strip which is 
formed of a support strip having a center rib along the length thereof 
adapted to matingly fit within a groove formed by the adjacent wallboard 
panels. The support strip extends laterally over at least a portion of the 
wallboard adjacent to the longitudinal edge of each of the adjacent 
wallboards. 
The support strip is made of material which is strong enough to withstand 
normal vibration that occurs during normal usage, for example, synthetic 
fibers, cellulose fibers, non-woven paper, plastic fibers, fiberglass, 
specially treated fabric, and mixtures thereof. Moreover, a mixture of 
synthetic fibers, cellulose fibers, plastic fibers, fiberglass, and 
non-woven paper can be used. The rib is adhesively secured to the support 
strip and may be constructed of PVC, recycled PVC, other plastics, rubber, 
cellulose, fiberglass, ceramic or the like, either in its pure or recycled 
state and mixtures thereof. The rib is affixed to the support strip so as 
to allow for flexing of the joint strip without delamination occurring. 
In practice, a wall is formed by attaching a pair of wallboards to wall 
studs or the like, in either abutting or closely adjacent relationship. 
The longitudinal edges of the wallboard sheets may be square edged or 
preformed edged. Further, the sheets may be either predecorated or 
undecorated. 
In the one embodiment, the wall is made with wallboard panels having 
preformed edges, say for example, at an angle such as a 45.degree. angle 
or the like such that a V-shaped groove is formed when the wallboard 
panels are adjacent to one another. The rib of the joint strip is then 
placed in the groove and the strip adhered to the longitudinal edge of the 
wallboards. In another embodiment, the wallboards are of the conventional 
square edged type at the time of attachment to the wall studs. Subsequent 
to attachment, a groove is cut along at least a substantial portion of the 
length of the joint between the adjacent wallboards. The rib of the joint 
strip is then placed in the groove and the strip secured to the 
wallboards. 
When the wall is completed using the joint strip of this invention, the 
joint surface is sufficiently smooth so that a monolithic appearing wall 
is formed when a topical treatment, e.g., paint or wall covering, is 
applied thereto.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now more specifically to the drawings, FIG. 1 shows a perspective 
view of a preferred embodiment of the monolithic appearing wall indicated 
generally at 10. With specific reference now to FIG. 2 of the drawings, it 
can be seen that wallboard panels 11 with a formed edge 12 are nailed in 
adjacent positions to stud 20 with nails 22. The wallboard 11 may be 
comprised of gypsum, fiberglass, plywood, fiberboard, particleboard, 
laminated cellulose sheets, epsom board, plastic, ceramic, or any 
combination of the above. It should be noted that the wallboards can be of 
any size and thickness. Typically manufactured sizes are 4'.times.8', 
4'.times.10', 4'.times.12', 2'.times.8', 2'.times.10', 2'.times.12' and 
thicknesses of 5/16", 3/8", 1/2", 5/8", 3/4", and 1". It should be 
understood that these dimensions of length, width, and thickness do not 
serve as a limitation upon the claimed invention. The determination of the 
relationship of the wallboard panels 11 to each other will depend upon the 
size and shape of joint strip 30, shown in FIG. 3. Although wallboard 
panels 11 are depicted as nailed to a wooden stud, it is contemplated that 
wallboard panels 11 of varying lengths, widths, and thicknesses may be 
nailed, screwed, stapled, glued, foamed or otherwise secured into place on 
metal, wood, fiberglass or plastic wall studs by centering the joint 
formed between adjacent panels 11 over a stud. In fact, if desired, two 
foot wide boards may be combined into a "sandwich" type construction using 
gypsum spacers to create a wall unit that does not require studs for 
support. 
Continuing to refer to FIG. 2, when wallboard panels 11 have been nailed to 
stud 20 in adjacent relationship, a groove G must be formed within the 
joint of the wallboard either by using preformed wallboards or by cutting 
the groove. Preformed edges may be produced by cutting the ends of square 
edged wallboard prior to installation or they may be formed during 
manufacturing of the wallboard panel. Although a V-shaped groove is shown 
in FIG. 2, a U-shaped or modified rectangular groove may also be formed. 
By preforming the edges, any irregularities in the thickness in square 
edge outside edges will be removed such that a desirable straight vertical 
joint is formed upon wallboard assembly. 
Referring now to FIG. 3, there is shown a semi-flexible joint strip 30. 
Joint strip 30 comprises a support strip 32 and a rib 34. Most suitably, 
the flexible support strip 32, about 4 to 5 inches wide, is a strip of a 
suitable thickness which may be constructed of synthetic fibers, cellulose 
fibers, non-woven paper, plastic fibers, fiberglass, specially treated 
fabric and mixtures thereof or a mixture of synthetic fibers, cellulose 
fibers, plastic fibers, fiberglass, and non-woven paper may be used. For 
the purposes of this invention, a specially treated fabric is any fabric 
which is capable of withstanding normal day-to-day vibrations and which is 
capable of concealing fastener indentations. For example, any woven or 
knitted fabric comprised of a variety of materials including, for example, 
a cotton-polyester blend, nylon, polyester, and the like, can be 
successfully employed. The fabric is specially treated in that starch, 
latex, or a backing of acrylic is applied to impart a sufficient level of 
stiffness. It should be stressed that in order to achieve sufficiently 
narrow support strip edges, a selvage of any suitable material may be 
employed in conjunction others listed. In one example, silk may be used. 
In a preferred embodiment, the support strip is a non-woven cellulose paper 
that has been calendared to about 0.0075.increment. thick at its thickest 
point. The smooth wall surface is obtained by calendaring the edges of the 
strip to a thickness of about 1 to 2 thousandths of an inch. A most 
preferred strip composition is a blend of cellulose material containing 
between about 10% and 50% by weight of polyester fibers, most preferably 
approximately 20% by weight of polyester fibers. The blend is processed 
via a calendaring process which uses water, heat (approximately 
275.degree. F.) and pressure (approximately 20 psi) to "mash" the 
irregularly aligned cellulose and polyester fibers into the finished 
sheet. While the thickness may vary the calendared sheet is from about 2 
to about 10 thousandths of an inch thick. When the edges of the strip have 
not been calendared to the desired thickness, the edges may be sanded to a 
thickness of about 1 thousandth of an inch thus allowing a visually flat 
joint seam to appear. Although in this embodiment polyester fibers are 
used for strength, other synthetic fibers such as nylon, fiberglass, and 
the like may also be employed. 
Rib 34 is adhesively secured to support strip 32. It should be noted that 
the purpose of the rib 34 is to fill the void created between adjacent 
wallboard panels upon formation of groove G such that a monolithic 
appearing wall may be formed. Accordingly, rib 34 may be constructed of 
any material suited for this stated purpose including, but not limited to, 
polyvinyl chloride (i.e., PVC), recycled PVC, other plastics, rubber, 
cellulose, polyvinyl acetate, fiberglass, ceramic or the like, either in 
its pure or recycled state. Mixtures of any of the above may also be 
utilized. Preferably, rib 34 is semi-flexible. In accordance with the 
invention, the term semi-flexible refers to those materials which allows 
rib 34 to be rolled up or otherwise compacted in any fashion without it 
breaking. Rib 34 is affixed by means of an adhesive to support strip 32 so 
as to allow for flexing of joint strip 30 without delamination occurring. 
Preferably, a hot melt glue is used to adhere a recycled PVC rib 34 to the 
support strip 32, although other adhesives may be used. Also, the shape 
and dimensions of rib 34 will normally correspond to the size and shape of 
groove G. In practice, however, a rib 34 of a thickness of about 5/16 of 
an inch is utilized regardless of the board panel thickness as the 
v-shaped surfaces of the rib do not have to contact groove G. Accordingly, 
rib 34 is able to freely float during normal day-to-day usage. 
Several advantages are realized by utilizing this improved joint strip. 
First, the material can withstand severe experimental tests for racking in 
which the wallboard panels are subjected to stress and movement to throw 
them out of parallel alignment. Such results indicate that the support 
strip material structure is capable of withstanding movement and vibration 
associated with day-to-day usage without breaking. Second, the support 
strip structural properties are such that the strip tautly spans across 
nail, screw, or fastener indentations formed when the wallboard is 
attached to studs. Third, the need to caulk the joint is eliminated as the 
irregularly aligned fibers in the support strip allow the strip to be 
flexible in many directions. When the wallboard moves and flexes, the 
support strip "floats" in the joint thus rendering the caulking 
unnecessary. Fourth, the use of water in the processing of the strip gives 
the support strip excellent tensile strength under wet and dry conditions. 
Finally, the support strip can be beveled to a thickness of about 1 
thousandth of an inch, creating a visually flat seam. 
As shown in FIG. 4, the joint strip 30 is affixed to wallboards 11 by means 
of an adhesive 36 such that rib 34 matingly fits within groove G. Several 
methods may be used in adhering the joint strip. 
1. A water-based adhesive which is preferably ethylvinyl acetate is 
brushed, rolled or sprayed onto the surface area adjacent to the side 
edges of the wallboards and the joint strip 30 is then pressed onto the 
wallboard surfaces with a roller, brush, by hand or by trowel. 
2. A pre-applied pressure sensitive adhesive is applied to the back of the 
joint strip 30. Just prior to application, the release paper is peeled 
away from the back of the joint strip 30, the rib 34 is positioned into 
the groove G and pressure is applied to the outside face of the joint 
strip 30 by a roller brush, trowel or by hand to press the support strip 
against the surface of the wallboard. 
3. A hot melt glue is pre-applied to the back of the joint strip 30. The 
rib is matingly positioned in the groove G and is held into position while 
an iron or other heating element is rubbed across the outside face of the 
joint strip 30. By using pressure and heat, the hot melt glue on the back 
of the joint strip 30 is adhered to the surface of the wallboard. 
In all three examples, ethylvinyl acetate is the preferred adhesive as it 
remains slightly flexible in its cured state, although other adhesives 
such as polyvinyl acetate may also be employed. It should be emphasized 
that regardless of the source of adhesive used to secure joint strip to 
the wallboard surface, the bonding thereof creates a smooth joint between 
wallboards without the necessity for sanding, puttying or filling of the 
joint or necessity of covering the joint with battens or the like. This is 
very significant since the joint strip 30 eliminates the mess and drying 
time required when using a "mud" system as well as the necessity for use 
of skilled laborers to form a smooth joint. Moreover, if the simple 
expedient of attaching battens were to be used to cover the joint, the 
appearance of the fully constructed wall is not monolithic and, in fact, 
unattractive due to the presence of periodic batten strips thereon. 
After the joint strip 30 is adhered to the wallboard 11, a topical 
treatment 38 may be employed to give the wall a monolithic, uniform 
appearance. This can be accomplished by utilizing either of two types of 
materials, paint or wallcovering. 
As shown in FIG. 5, either a heavy bodied paint or an aggregate based paint 
is preferred as a paint covering. The heavy bodied paint should be thick 
enough to cover the joint strip and surrounding wallboard such that the 
edges of the joint strip will not show through the paint surface. An 
aggregate based paint is a paint that has aggregate materials added to the 
paint mixture to give the painted surface a textured or pebbled finish. 
The addition of aggregate gives any paint additional hiding ability to 
prevent the edge of the joint strip from showing through the finish. It 
should be noted that the wallboard and joint strip may be sanded before 
the paint is applied or between coats of paint in accordance with the 
current industry norm; nonetheless, this sanding step is not necessary. 
In the embodiment shown in FIG. 6A, a predecorated wallcovering sheet can 
be employed as a cover over the joint. In this instance, applying paint or 
wallcovering to the wallboard is no longer necessary as the predecorated 
sheet serves to create a monolithic, seamless appearing wall. 
Representative methods of assembling of predecorated square edge wallboard 
panels is described in U.S. Pat. No. 5,311,717, incorporated herein by 
reference. Any wallcovering such as paper, non-woven paper, vinyl, backed 
vinyl, fiberglass, synthetic fibers, grasses, hemp, other natural products 
and mixtures thereof can be used. The wallcovering is applied to the wall 
on-site using the wallcovering manufacturer's recommendations. 
With reference to FIG. 6A, the predecorated wallboard wall and the method 
of construction thereof can be further described. In this embodiment, it 
can be seen that predecorated beveled edge wallboards 11 are placed in 
abutting relationship over wooden stud 20 and nailed thereto with nails 
22. It should be appreciated that the wallboards do not have to be in 
abutting relationship. The determination of the relationship of the 
wallboards to each other will depend upon the size of the joint strip 30. 
Although wallboards 11 are depicted as nailed to a wooden stud, it is 
contemplated that predecorated square edge wallboards 11 of varying 
lengths, widths, and thicknesses may be nailed, screwed, stapled, glued, 
foamed or otherwise secured into place on metal wood, fiberglass or 
plastic wall studs by centering the joint formed between adjacent 
wallboard panels 11 over a stud. When adjacent wallboard panels 11 have 
been nailed to stud 20 in adjacent relationship to form the joint, 
predecorated sheets 12 are pulled backward to expose a 3 inch uncovered 
gypsum board surface strip adjacent to the side edge of each gypsum board 
14 and the groove formed and the joint covered by one of the methods 
described in U.S. Pat. No. 5,311,717. 
Referring also to FIG. 6A, it can be appreciated that in order to fully 
finish the smooth joint formed by the adherence of the joint strip 30 to 
groove G, the edge flaps of the predecorated sheets 12 are released and 
allowed to overlap. Next, a vertical cut is made through both edge flaps 
with a metal straight edge and razor blade or knife, and the edge flaps 
are peeled back and loose edge strips 12 are removed. 
Additionally, wallcovering may be applied to the adjacent wallboard panels 
after installation of the joint strip 30. FIG. 6B, for example, depicts 
wallcovering which has been applied on site. In accordance with the 
invention, the wallcovering can cover adjacent wallboard panels in any 
fashion that allows a monolithic appearing surface to result. In FIG. 6B, 
the edge flaps of the wallcovering are positioned away from the joint 
strip; it should be stressed that this illustrated embodiment is not 
limiting, but is only one example of numerous variations. 
In should be appreciated that although certain features of the invention 
are shown in slightly enlarged representation in several drawings for 
greater clarity of understanding, the wallboard joint contemplated by the 
invention is substantially flat and parallel to the outer wall surfaces 
and thus forms a "seamless" and monolithic appearing wall. The 
semiflexible nature of the joint strip allows it to be formed into rolls 
for easy handling. 
It will be understood that various details of the invention may be changed 
without departing from the scope of the invention. Furthermore, the 
foregoing description is for the purpose of illustration only, and not for 
the purpose of limitation--the invention being defined by the claims.