U.S. patent application number 11/301323 was filed with the patent office on 2006-06-15 for system and method for filling joints between exterior cement panels.
Invention is credited to Sanford Futterman.
Application Number | 20060123736 11/301323 |
Document ID | / |
Family ID | 36582193 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060123736 |
Kind Code |
A1 |
Futterman; Sanford |
June 15, 2006 |
System and method for filling joints between exterior cement
panels
Abstract
Buildings and walls are commonly constructed with exterior walls
composed of fiber exterior panels, such as fiber cement panels or
glass reinforced gypsum exterior sheeting. The spaces between the
exterior panels are sealed using the system and method of the
present invention. The space is first filled with an acrylic
flexible joint compound. A thermally set, spunbonded, reinforced,
polyester non-woven joint tape is then applied. The tape is then
covered with a ceramic mud. After curing of the ceramic mud an
acrylic elastomeric coating is sprayed, brushed or rolled on the
fiber cement panels. A cement-free stucco coating or a variety of
other coatings may then be applied over the exterior panels.
Inventors: |
Futterman; Sanford;
(Lakeway, TX) |
Correspondence
Address: |
Strasburger & Price, LLP
Suite 4300
901 Main Street
Dallas
TX
75202
US
|
Family ID: |
36582193 |
Appl. No.: |
11/301323 |
Filed: |
December 12, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60635598 |
Dec 13, 2004 |
|
|
|
Current U.S.
Class: |
52/742.16 |
Current CPC
Class: |
C04B 41/52 20130101;
E04F 13/04 20130101; C04B 41/009 20130101; C04B 41/52 20130101;
C04B 41/009 20130101; C04B 2111/00612 20130101; C04B 41/52
20130101; C04B 41/483 20130101; C04B 28/02 20130101; C04B 41/524
20130101; C04B 41/5037 20130101; C04B 41/483 20130101; C04B 26/06
20130101; E04F 13/042 20130101; C04B 26/06 20130101; C04B 41/009
20130101; C04B 2111/00672 20130101; C04B 41/52 20130101 |
Class at
Publication: |
052/742.16 |
International
Class: |
E04G 23/00 20060101
E04G023/00 |
Claims
1. A method for sealing the spaces between panels on exterior walls
comprising the steps of: filling the joint with an acrylic based
flexible joint compound; taping over said acrylic based flexible
joint compound with a reinforced spunbonded joint tape; applying a
layer of a ceramic mud over said tape; covering the entire panel
with an acrylic elastometric coating;
2. The method as defined in claim 1 wherein the acrylic
elastometric coating is tinted to a desired color.
3. A method for repair of imperfections in exterior wall panels
comprising steps of: filling the imperfection with an acrylic based
flexible joint compound; smoothing the filled imperfection with a
ceramic mud; applying layering an acrylic elastometric coating over
said ceramic mud;
4. A method for sealing the spaces between exterior panels used in
the construction of exterior walls comprising the steps of: filling
the space with acrylic flexible joint compound, covering the said
acrylic flexible joint compound with thermally set, spunbonded
polyester nonwoven reinforced joint tape; and applying an acrylic
elastomeric coating.
5. The system as defined in claim 4 wherein said acrylic
elastomeric coating is tinted to a desired color.
6. A wall constructed of a plurality exterior panels affixed to an
internal frame in which the spaces between said exterior panels are
filled and sealed by the method of claim 4.
7. The wall as defined in claim 6 further including a cement free
stucco exterior finish.
8. A building comprising: a plurality of exterior panels affixed to
the building, said exterior panels having spaces there between
wherein: the spaces between said exterior panels are filled with an
acrylic flexible joint compound over which is layered a thermally
set, spunbonded polyester nonwoven reinforced joint tape which
optionally may be covered with ceramic mud to which an acrylic
elastomeric coating is added.
9. The building as defined in claim 8 further including a cement
free stucco exterior finish.
10. A system for filling and sealing the spaces between fiber
cement panels attached to a building frame comprising a dual
acrylic rubber-like gasket sandwich with or without a ceramic core.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application Ser. No. 60/635,598, filed Dec. 13, 2004, the
disclosure of which is incorporated by reference as if fully set
forth herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Federally Sponsored Research or Development was not used in
the invention.
FIELD
[0003] The present invention relates to an improved system and
method for sealing the spaces between exterior cement panels
fastened to building frames to allow for the application of paint,
a synthetic stucco finish or other covering on the exterior cement
panels.
BACKGROUND
[0004] Stucco finishes are an example of an exterior finish that
has been used on buildings since ancient times. Still widely used
throughout the world, stucco exterior finishes make up one of the
most common ways of finishing exteriors of both residences and
commercial buildings.
[0005] Like interior wall plaster, a stucco finish has
traditionally been applied on exterior surfaces as a multiple-layer
process, sometimes consisting of one, two, but more commonly as
three coats. Whether applied directly to a masonry substrate or
onto wood or metal lath, the process of applying a stucco finish
includes the step of applying a first "scratch" or "pricking-up"
coat, followed by a second scratch coat, sometimes referred to as a
"floating" or "brown" coat, followed finally by the "finishing"
coat, Up until the late-nineteenth century, the first and the
second coats were of much the same composition, generally
consisting of lime or portland cement, sand, perhaps clay and one
or more other natural additives. Straw or animal hair was usually
added to the first coat as a binder.
[0006] The third, or finishing coat, consisted primarily of a very
fine mesh grade of lime and sand, and sometimes pigment.
[0007] Although traditional stucco exterior finishes have been used
for quite some time, traditional stucco exterior finishes have
their limitations. Those limitations include porosity, rigidity,
freeze/thaw fractures, fungal and mildew formation, cracking,
complexity of installation, high maintenance and the requirement
for a specialized labor pool to apply the stucco exterior
finish.
[0008] Because modern synthetic stucco exterior finishes are
watertight, any water that remains trapped behind these modern
synthetic stucco exterior finishes does not readily evaporate. The
trapped water behind the stucco exterior finish can then soak into
the substrata and framing of the building. The water that soaks
into the substrata and framing often causes severe damage to the
building without any signs of damage appearing on the exterior of
the building. These problems can exist regardless of the age of the
building or the quality of construction. Another problem leading to
severe damage is insulation cladding. Specifically, insulation
cladding is unforgiving for water penetration or condensation.
Moreover, the durability of the cladding itself is prone to
penetration by abrasion, birds, insects and airborne debris.
[0009] Although modern synthetic stucco exterior finishes are
attractive and long lasting, their usefulness is compromised by the
integrity of the foundation to which it is applied. It has been
found that one of the most durable foundations for a synthetic
stucco exterior finishes uses fiber cement panels affixed to the
building frame.
[0010] The recent introduction of a fiber-cement panel available in
4.times.8, 9 and 10 ft lengths and in 1/4 and 5/16.sup.th inch
widths, has provided an opportunity to replace prior art systems
with a preformed fiber cement panel that can be installed like wood
paneling or interior drywall panels. However, just like interior
drywall panels, exterior fiber cement panels, when installed, have
seams or joints between each panel that must be filled so that a
smooth exterior finish may be applied there over.
[0011] To create a pleasing and uniform appearance for the exterior
of a building, the outline of each exterior fiber cement panel
should be invisible. For interior drywall panels, hiding the
outline of each drywall panel is achieved by tapering the edges of
the individual panels so that when the drywall panels abut one
another, the tapered edges provided a channel suitable for the use
of tape and mud to hide the resulting seams. The process of taping
and placing mud over the tape creates a smooth transition between
drywall panels. Unfortunately, unlike interior drywall panels with
their tapered edges, exterior fiber cement panels do not have
tapered edges and do not form a channel which is easily filled and
masked. Hence, when exterior fiber cement panels are placed along
side each other on the exterior of a building, a butt-joint with
square edges is created. The butt-joint between the exterior fiber
cement panels is difficult to disguise. In addition, the edges of
each exterior fiber cement panel are subject to the stresses of
building movement, temperature changes and other environmental
factors. Accordingly, the foregoing factors must be considered when
finishing an exterior wall so that no seams or joints between
exterior wall panels are visible.
[0012] One prior art solution teaches simply filling the gaps
between exterior fiber cement panels with a polyurethane caulk. The
polyurethane caulk is then covered with a 3-inch wide, peal and
stick butyl-rubber tape having a fabric backing. This butyl-rubber
tape and the rest of the panel is then coated with an exterior
synthetic stucco finish coat. This solution has proven to be
unsatisfactory because it overlooks the problems of out-gassing
from the polyurethane caulk. Specifically, if the caulk isn't fully
cured due to time or climate constraints and is then covered by a
non-permeable butyl rubber tape, the emission of gas from the
polyurethane caulk causes blisters or ridges to form in the
butyl-rubber tape as the trapped gas tries to escape (out gas) from
the polyurethane caulk. In addition, there is also a tendency for
the butyl-rubber tape to show noticeable bumps if any air becomes
trapped while handling and applying the butyl-rubber tape to the
panel. Furthermore, the butyl-rubber tape is extremely tacky and by
its very nature, may bulge outwardly from the butt-joint between
the exterior fiber cement panels when the tape is smoothed flat
against the surface of the exterior fiber cement panel.
[0013] The prior art approach of placing butyl-rubber tape over a
polyurethane caulk overlooks the problem presented by a butt-joint
between exterior fiber cement panels. By sealing the polyurethane
caulk with a butyl-rubber tape, an elevation is created at the
seams between the exterior fiber cement panels. This elevation
accentuates the outline of the panels. Flexibility at the
butt-joint between the exterior fiber cement panels is then
compromised. To address the problem of accentuating rather than
hiding panel outlines, applicators have attempted to place multiple
layers of a stucco exterior finish over the exterior fiber cement
panels. These multiple layers of stucco increase the material and
labor cost. Moreover, any irregularities still evident after the
stucco exterior finish is applied will be very difficult, if not
impossible, to hide. Lastly, the use of a butyl-rubber tape over a
polyurethane caulk also overlooks the benefits of a weep screed,
thereby compromising drainage of any moisture penetration.
[0014] Accordingly, there still remains a need in the art for a
system and method for filling the space between exterior panels,
that provides a smooth appearance for painting or the application
of an exterior finish such as stucco, paint, or other commonly used
finish.
SUMMARY
[0015] The system and method of the present invention provides for
filling the space between exterior panels, such as fiber cement
panels, to provide a smooth appearance suitable for painting, the
application of a stucco or an other finish which will last for the
life of the building onto which the exterior panels are
attached.
[0016] First, an acrylic flexible joint compound is layered into
and over the space between the fiber cement panels. Next, a
thermally set, spunbonded polyester nonwoven reinforced joint tape
is placed over the space filled by the acrylic flexible joint
compound. Following the application of the thermally set spunbonded
polyester nonwoven joint tape a ceramic mud is applied. Following
the application of the ceramic mud a colored acrylic elastomer
coating can be applied over the ceramic mud and there entire wall
assembly. Paint or stucco or other finish may then be applied over
the colored base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] A better understanding of the system and method for filling
joints between exterior panels may be had by reference to the
drawing figure, wherein:
[0018] FIG. 1 is a perspective of an exterior wall illustrating the
system and method of the disclosed invention;
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] This present invention describes an improved system and
method for preparing and finishing exterior panels or other cement
board formats with cement free, exterior textured wall coatings and
finishes.
[0020] The invention as shown in FIG. 1 involves a hybrid
application process that prepares exterior panels, such as
fiber-cement panels, or glass reinforced gypsum exterior sheeting
like interior gypsum drywall for the purpose of creating a smooth
exterior stucco or painted finish. Exterior fiber-cement panels are
first secured to the building frame per manufacturer's guidelines.
The spaces between the panels are then filled and effectively made
to disappear by use of the disclosed system and method.
[0021] This disclosed system and method enables the creation of
stucco like finishes, over fiber cement panel walls, with greater
strengths and benefits not present in typical stucco or prior art
exterior insulation finish systems. This disclosed system and
method may be best understood by those of ordinary skill in the art
as a tape and float system that integrates the skills, techniques
and materials from heretofore unrelated areas to create a smooth
base for stucco-like finishes and textures.
[0022] Like drywall, fiber-cement wall panels are installed on an
exterior building frame with the adjacent edges of the panels
butted together. An optional weep screed termination at the base of
the panel provides a level line, a drainage plane and corner bead
like protection. In the preferred embodiment of the invention, once
the fiber cement panels are mounted to the building frame, an
acrylic flexible joint compound such as sold under the trademark
AcraCream.RTM. by Global Coatings, Inc. is applied with a 6-inch
joint knife over the center of the butt-joint. In the preferred
embodiment 4-inch, thermally set, spunbonded polyester reinforced
nonwoven joint tape, is laid into the acrylic flexible joint
compound and embedded into the acrylic flexible joint compound with
the aid of the joint knife. Those of ordinary skill in the art will
understand that other types of take having similar properties such
as fiberglass tape may be used without departing from the scope of
the disclosed invention. Heretofore, the thermally set, spunbonded
polyester nonwoven reinforced joint tape used with the system and
method of the present invention had been used primarily in the
manufacture of furniture and commercial roof seam sealing. Once
cured, the acrylic flexible joint compound shrinks into any gap,
then fills and seals the spaces between the fiber cement panels.
The acrylic flexible joint compound may also be used on metal or
plastic corner beads to build them out to be flat and smooth. The
thermally set spunbonded, reinforced polyester non-woven joint
tape, is embedded into the acrylic flexible joint compound. It has
been found that the thermally set spunbonded, reinforced polyester
non-woven reinforced joint tape provides added stability and
flexibility to the cured acrylic flexible joint compound. The
preferred AcraCream.RTM. joint compound is a mixture by weight of
Acrylic Polymer 54%, Calcium Carbonate 30%, Water 5%, isobutane 4%,
titanium dioxide 2% and petroleum derivatives 2%.
[0023] Together, the acrylic flexible joint compound and the
thermally set spunbonded, reinforced polyester non-woven reinforced
joint tape, both seal and waterproof the butt-joint with a rubber
gasket-like membrane. This tough rubber gasket-like membrane
accommodates and flexes along with the exterior building panels.
Moreover, the remaining profile of the butt-joint is minimal, and
the rubber gasket-like membrane provides an acrylic adhesive
bedding for the use of the ceramic mud that follows.
[0024] Once the thermally set spunbonded, reinforced, polyester,
non-woven reinforced joint tape has been smoothed over the acrylic
flexible joint compound, a ceramic mud is applied. It has been
found that a ceramic mud sold under the trademark Fill-N-Build.RTM.
by Global Coatings, Inc. provides satisfactory results. Heretofore
Fill-N-Build ceramic mud had only found utilization for filling the
spaces under interior hardwood floors. Fill-N-Build ceramic mud is
a mixture by weight of Acrylic copolymer solution 30%, hydrated
aluminum silicate mineral 19.5%, soda lime borosilicate glass 10%,
kaolin clay 8%, Titanium dioxide 4%, and ammonium salt of acrylic
polymer 1%. As with interior drywall that has been installed
without a tapered edge, the exterior fiber cement panel needs to be
floated out 10 or more inches on each side of the butt-joint. This
floating and feathering of the butt-joint between the exterior
fiber cement panels, helps flatten and level the exterior wall so
that the spaces between the panels are no longer noticeable. Like
interior drywall mud, the ceramic mud may also be applied over all
nail heads. It has been found, those using the system and method of
the present invention that if the acrylic flexible joint compound
can be made to be extremely smooth only a small amount, if any,
ceramic need be used.
[0025] Unlike the mud used with interior drywall the ceramic mud
used in the system and method of the present invention is a
gypsum-free, ceramic-acrylic-clay matrix that, once cured, does not
dissolve or deteriorate when exposed to exterior weather. The
ceramic mud is applied over the tape using a 10 or 12-inch mud
knife and then floated 10-12 inches on each side of the thermally
set, spun bonded, reinforced polyester non-woven joint tape over
the butt-joint creating a total width of 20-24 inches of ceramic
mud over the butt-joint between the fiber cement panels. Care must
be taken not to apply much ceramic mud over the center of the
butt-joint but rather to float the ceramic mud away from the
butt-joint to create a seamless and flat transition between the
exterior fiber cement panels.
[0026] The ceramic mud may also be used to treat metal or plastic
corner beads, building them out until the corner beads are flat and
smooth with the exterior fiber cement panel. Another major benefit
of the system and method of the present invention is the capability
of straightening the appearance of a wall that has been compromised
by irregular studs. The ceramic mud can mask most any irregularity
in the wall surface. As the ceramic mud is formulated with acrylic
mastic, it provides a strong bond and cures with the underlying
acrylic flexible joint compound. When dry, the ceramic mud may be
sanded if required, providing an extremely smooth, flat surface for
the application of the acrylic elastomeric coating that
follows.
[0027] An acrylic elastomeric coating is then applied over the
entire exterior cement fiber panels, including the area over the
butt-joint. The acrylic elastomeric coating may be tinted to be the
same color as the textured exterior finish top-coat which is either
spray-applied, rolled or brushed onto the exterior of the building.
Some applicators have found that the acrylic stomoric coating, if
applied well, can be a satisfactory exterior coating. In actual
applications, it has been observed that the acrylic based flexible
joint compound cures to a tough acrylic rubber-like substance, and
the acrylic elastomeric coating cures to a softer acrylic
rubber-like substance with excellent freeze/thaw properties. Hence,
the colder it gets, the more elastomeric it becomes. It has been
found that an acrylic elastomeric coating sold under the trademark
ColorFlex.RTM. by Global Coatings, Inc. provides satisfactory
results. ColorFlex is a mixture by weight of acrylic polymer 43%,
calcium carbonate 36%, water 11% titanium dioxide 5%, and calcium
carbonate 3%.
[0028] This system and method of the present invention creates a
dual acrylic rubber gasket sandwich with a ceramic core.
Specifically, the tougher acrylic based flexible joint compound
absorbs the building stress and the acrylic high performance
colored coating provides a secondary exterior crack bridging and
color prime component. When complete, the fiber cement wall appears
as a smooth surface with none of the spaces or space treatment
visible.
[0029] In another embodiment of the system and method of the
present invention is the capability to touch up any wall areas in
which a smooth surface is not observed. Specifically, before the
final synthetic exterior texture is applied, further application of
the ceramic mud over the acrylic flexible joint compound is
possible. Once the ceramic mud has been applied, the acrylic
elastomeric coating is applied.
[0030] Those of ordinary skill in the art will understand that the
acrylic elastomeric coating is an integral component of a 4-ply
membrane that includes both the underlying ceramic mud and acrylic
flexible joint compound. The first layer of the acrylic flexible
joint compound forms a tough acrylic rubber-like substance that
acts like a shock absorber and waterproof membrane between the wall
panels. The second layer is the thermally set, spunbonded,
reinforced polyester nonwoven reinforced joint tape. The third
layer of ceramic mud provides a smooth seamless foundation that
bridges the space between the fiber cement panels and fills or
levels any irregularities in the fiber cement panels themselves.
The last layer is the acrylic elastomeric coating which provides
secondary crack bridging capabilities and also accommodates
exterior freeze/thaw.
[0031] Various exterior textures can then be applied to the fiber
cement panel building exterior depending on the aggregate mix and
the application technique. If synthetic stucco is used, the
synthetic stucco cures to a stone-like veneer providing added
durability to the underlying fiber cement panels. Furthermore, the
system and method of the present invention provides independent
elastomeric properties in the underlying acrylic coating and the
components in the acrylic flexible joint compound synergistically
work together to provide greater system flexibility and
durability.
[0032] While the system and method of the present invention has
been disclosed according to its preferred and alternate
embodiments, those of ordinary skill in the art will understand
that other embodiments of the invention are possible based on the
foregoing disclosure. For example, while the disclosed system and
method has been described with regard to fiber-cement panels, those
of ordinary skill in the art will understand its utility with other
types of exterior such as fiberglass reinforced gypsum board. Such
other embodiments shall be included with the scope and meaning of
the appended claims.
* * * * *