U.S. patent application number 12/165120 was filed with the patent office on 2009-02-05 for lath support system.
Invention is credited to WILLIAM CLYDE FOSTER, MARY JANE HUNT-HANSEN, WILLIAM L. JOHNSON, SR., ROBERT WAYNE LOVE.
Application Number | 20090031656 12/165120 |
Document ID | / |
Family ID | 40226803 |
Filed Date | 2009-02-05 |
United States Patent
Application |
20090031656 |
Kind Code |
A1 |
HUNT-HANSEN; MARY JANE ; et
al. |
February 5, 2009 |
LATH SUPPORT SYSTEM
Abstract
A structural reinforcement system that utilizes a lath for
receiving cementitious material. Lath is affixed to support
structure such as sheathing supported by studs as may commonly be
found in building construction. Strip members are affixed to the
lath and function as fastener guides. Fasteners penetrate the
strips for affixing lath and strips to the support structure. The
strips are made of a compressible material that protects the lath
from damage due to impacts associated with installing the fasteners
and forms a gasket-like seal around the fasteners. Strips may be
used as drainage guides for directing water that may flow behind
the lath. The width of the strips creates spacing between the lath
and the support structure, which allows for controlling of a
thickness of a base layer of cementitious material by selecting a
desired width. In another embodiment, entangled filaments are used
as lath material for receiving cementitious material.
Inventors: |
HUNT-HANSEN; MARY JANE;
(GROVE, OK) ; LOVE; ROBERT WAYNE; (NORPHLET,
AR) ; FOSTER; WILLIAM CLYDE; (VANCOUVER, WA) ;
JOHNSON, SR.; WILLIAM L.; (GROVE, OK) |
Correspondence
Address: |
FELLERS SNIDER BLANKENSHIP;BAILEY & TIPPENS
THE KENNEDY BUILDING, 321 SOUTH BOSTON SUITE 800
TULSA
OK
74103-3318
US
|
Family ID: |
40226803 |
Appl. No.: |
12/165120 |
Filed: |
June 30, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60937623 |
Jun 28, 2007 |
|
|
|
Current U.S.
Class: |
52/344 ;
52/746.1 |
Current CPC
Class: |
E04B 2/845 20130101;
E04F 13/0803 20130101; E04F 13/047 20130101; E04F 13/04 20130101;
E04F 13/045 20130101 |
Class at
Publication: |
52/344 ;
52/746.1 |
International
Class: |
E04F 13/04 20060101
E04F013/04 |
Claims
1. A structural reinforcement system comprising: a lath having a
front surface and a rear surface, said lath for affixing to a
support structure; a plurality of strip members affixed to one of
said front surface and said rear surface of said lath; fasteners
penetrating said plurality of strip members for affixing said lath
and said strip members to said support structure.
2. The structural reinforcement system according to claim 1 further
comprising: a water/vapor barrier adjacent to said support
structure.
3. The structural reinforcement system according to claim 1 further
comprising: a water/vapor barrier adjacent to said mesh for
functioning as a mortor stop to prevent mortar from migrating
behind said lath.
4. The structural reinforcement system according to claim 1
wherein: said lath is a mesh structure.
5. The structural reinforcement system according to claim 4
wherein: said lath is comprised of fiberglass.
6. The structural reinforcement system according to claim 1
wherein: said lath is comprised of entangled filaments.
7. The structural reinforcement system according to claim 1
wherein: said lath is metallic.
8. The structural reinforcement system according to claim 1
wherein: said strip members are flexible.
9. The structural reinforcement system according to claim 1
wherein: said strip members are comprised of fastener guides and
drainage strip members.
10. The structural reinforcement system according to claim 9
wherein: said fastener guides are comprised of closed cell
foam.
11. The structural reinforcement system according to claim 9
wherein: said drainage strip members are comprised of open cell
foam.
12. The structural reinforcement system according to claim 1
wherein: said strip members provide a water tight seal around said
fasteners when said fasteners penetrate said strip members.
13. The structural reinforcement system according to claim 1
wherein: said strip members are comprised of a material that
provides a seal around said fasteners when said fasteners penetrate
said strip members wherein said seal protects said fasteners from
exposure to alkaline substances.
14. The structural reinforcement system according to claim 1
wherein: said strip members absorb impacts associated with
installing said fasteners for preventing said lath from being
damaged.
15. The structural reinforcement system according to claim 1
wherein: said strip members are directly adhered to said lath after
said lath is affixed to said support structure.
16. The structural reinforcement system according to claim 1
wherein: said strip members are affixed to said lath prior to
attachment of said lath to said support structure.
17. The structural reinforcement system according to claim 1
wherein: said strip members are first adhered to said lath and then
mechanically fastened to said lath.
18. The structural reinforcement system according to claim 1
wherein: said strip members may be affixed to said lath at a
desired spacing to meet construction requirements.
19. The structural reinforcement system according to claim 1
wherein: said drainage strip members are strip members oriented
non-horizontally and non-vertically for directing water that passes
behind said lath.
20. The structural reinforcement system according to claim 2
wherein: said strip members are affixed to said water/vapor
barrier.
21. The structural reinforcement system according to claim 4
wherein: said mesh structure is comprised of a first group of
strands and a second group of strands; wherein said first group of
strands and said second group of strands are woven together in a
leno weave.
22. The structural reinforcement system according to claim 21
wherein: said first group of strands and second group of strands
have cupping between adjacent transverse strands.
23. The structural reinforcement system according to claim 4
wherein: strands of said mesh structure have an anticorrosion
coating.
24. The structural reinforcement system according to claim 1
further comprising: cementitious material applied to said front
surface of said lath.
25. The structural reinforcement system according to claim 24
wherein: said cementitious material encapsulates said lath by
passing through to said rear side of said lath to form a base
layer.
26. The structural reinforcement system according to claim 25
wherein: a thickness of said base layer is regulated by a thickness
of said strip member.
27. A method of installing a structural reinforcement system
comprising the steps of: affixing a plurality of strip members to a
lath; locating said lath with attached strip members on a support
structure; fastening said lath to said support structure with
fasteners; wherein said fasteners pass through said strip members
before engaging said support structure.
28. The method according to claim 27 further comprising the step
of: applying a cementitious material to said lath.
29. The method according to claim 27 wherein: said strip member
absorb an impact of said step of fastening, thereby protecting said
lath.
30. The method according to claim 27 further comprising the step
of: selecting a thickness of said strip member to regulate a
thickness of a base layer of cementitious material that migrates in
between said lath and said support structure.
31. The method according to claim 27 wherein: said fasteners also
pass through a water/vapor barrier before engaging said support
structure.
32. The method according to claim 27 further comprising the step
of: sealing said fasteners with said strip member to prevent
moisture from passing around said fastener.
33. The method according to claim 27 further comprising the step
of: sealing said fasteners with said strip member to protect said
fastener from exposure to alkaline substances.
34. The method according to claim 27 wherein: said step of affixing
said plurality of strip members to a lath includes orienting at
least a portion of said strip members so that after said step of
fastening said lath to said support structure with fasteners, said
at least a portion of said strip members are non-horizontal and
non-vertical for directing water that passes behind said lath.
35. The method according to claim 28 wherein: said step of applying
a cementitious material to said lath comprises encapsulating said
lath by forming a base layer of cementitious behind said lath.
36. The method according to claim 34 further comprises the step of:
regulating a thickness of said base layer by selecting a desired
thickness of said strip member.
37. The method according to claim 34 wherein: said step of affixing
a plurality of strip members to a lath comprises the step of
selecting a desired spacing for said strip members so that said
fasteners will have a desired spacing to satisfy spacing
requirements.
38. The method according to claim 27 further comprising a step of:
affixing a water/vapor barrier to said support structure.
39. The method according to claim 27 further comprising a step of:
affixing a water/vapor barrier between said strip members and said
lath; wherein said step of affixing a plurality of strip members to
said lath includes affixing said strip members to said water/vapor
barrier affixed to said lath; and wherein said step of fastening
said lath to said support structure includes fastening said lath,
said water/vapor barrier and said strip members to said support
structure as a unit.
40. A structural reinforcement system comprising: a lath of
entangled fibers for affixing to a support structure; cementitious
material applied to a front side of said entangled fibers.
41. The structural reinforcement system according to claim 40
wherein: said entangled fibers are affixed to backing sheet.
42. The structural reinforcement system according to claim 41
further comprising: a plurality of strip members affixed to said
backing sheet.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional Patent
Application No. 60/937,623, entitled "NON-METALLIC MESH SUPPORT
SUBSTRATE," filed Jun. 28, 2007, the contents of which are hereby
incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to improvements in lath
support systems for use in a variety of applications. The present
invention is also directed to a method of applying lath and strip
members as part of a structural reinforcement system.
BACKGROUND OF THE INVENTION
[0003] Plastering is one of the oldest crafts in the building
trades. Plastering remains popular due to the durability and
relatively low cost of materials. Plasterers apply plaster to
interior walls and ceilings to form fire-resistant and relatively
soundproof surfaces. A plaster veneer may also be applied over
drywall to create smooth or textured abrasion-resistant finishes.
In addition, prefabricated exterior insulation systems may be
applied over existing walls. Stucco masons apply durable plasters,
such as polymer-based acrylic finishes and stucco, to exterior
surfaces.
[0004] Plasterers can plaster either solid surfaces, such as
concrete block, or supportive wire mesh called lath. When
plastering metal-mesh lath foundations, plasterers apply a
preparatory, or "scratch coat" with a trowel. The scratch coat is
spread into and over the lath. Before the plaster sets, plasterers
scratch the surface of the scratch coat with a rake-like tool to
produce ridges, so that the subsequent brown coat will bond
tightly. The brown coat may then be applied. Later, the finish, or
white coat is applied onto the scratch coat. Similar steps are
followed when applying stucco and other materials to the lath.
[0005] The structure of the lath is what provides mechanical
integrity to an overall masonry system. When mortar fills the small
voids, it is called keying. Expanded lath has applications in the
installation or manufacture of tile, countertops, shower surrounds,
manufactured stone and natural stone veneers, brick, concrete
stairs, and other masonry systems.
[0006] A commonly used lath material is metal lath. Metal lath is
typically manufactured from steel sheets that are slit and expanded
to form diamond shaped openings. The openings provide keys for
securing plaster or a cementitious substrate such as stucco to the
lath material, whether the base material is troweled on or
mechanically applied. In addition, the shape of the orifice is
designed to promote keying of the cementitious material to the
lath.
[0007] If the metallic lath is weakened by corrosion, cracks tend
to result in the cementations material. In some cases, crack
propagation may result in cracking of the stone, plaster, or
stucco, which may be visible, unattractive, and unstable.
Galvanized metal lath was introduced in an attempt to prolong the
life of the metal lath in a corrosive cementitious environment. The
corrosive effects resulted from moisture and alkalinity due to the
lime content in cement based mortar. However, galvanized metal lath
still has a tendency to rust and deteriorate, thus providing a
substrate that is prone to fail. Efforts have been made to develop
non-metallic reinforcement systems and to use those systems for
both structural and crack resistant properties. Fiberglass and
plastic lathing systems have been introduced in the industry. The
fiberglass and plastic lath have advantages, such as ease of
handling, i.e., fiberglass and plastic lath come in rolls and are
lighter than traditional metal lath, and the fiberglass and plastic
lath does not rust. Additionally, plastic or fiberglass lath is
easier to use because it may be cut with a sharp blade of a utility
knife. Plastic lath is mainly used in the plaster and floor overlay
applications. Examples of fiberglass and plastic lath include
products sold under the trademark Ultra-lath.RTM.. Permalath.RTM.
and Fiberlath are other fiberglass products used in structural
reinforcement.
[0008] Fiberglass mesh, while not usually subject to corrosion, can
be affected by the corrosive nature of cementitious material. For
that reason, fiberglass mesh used as lath is usually coated with an
alkali resistant material like zirconium dioxide to protect the
fiberglass from the corrosive nature of many cementitious
materials. The oxidation of fiberglass has been proven to not
create structural degradation or mechanical weakening, unlike
metallic materials embodied in cementitious material.
[0009] When constructing a wall system, studs are typically used to
hold up the wall and sheathing is applied to the studs as a
covering. To protect the sheathing, which is usually untreated
wood, a vapor or water barrier is placed on the sheathing to stop
moisture from reaching the untreated wood. Water/vapor barriers are
usually tar paper, felt paper, plastic and more recently Tyvek.RTM.
building wrap. If the water proofing layer is perforated, then the
water barrier is compromised. Once water has penetrated the water
barrier any untreated wood is susceptible to damage, such as dry
rot and mold. One opportunity for perforating the water proofing
layer is when structural support systems are applied over the water
barrier and fastened to the substrate. In the fastening process the
fasteners penetrate the water barrier, thus compromising the
barrier and allowing a pathway for moisture to come in to contact
with the wood sheathing. In the process of installing the lath as
many as 200 penetrations in an 18 sq. ft. area may be found, thus
causing irreparable damage to the water barrier and to the
structural framing.
[0010] Additionally, when fasteners are in contact with moisture
for prolonged period of time, such as water saturated wood, the
galvanized anchors undergo corrosive fatigue and lose their
structural integrity as a valid anchor or a mechanical
fastener.
[0011] Therefore, it is desirable to provide an improved structural
reinforcement system that provides integral waterproof sealing
capabilities for anchor penetration through the water/vapor
barrier.
[0012] It is further desirable to provide a structural
reinforcement system that reduces the impact of the mechanical
anchoring device during fastener application to prevent damage to
the surface of the structural reinforcement system when secured to
the anchoring point to prevent corrosion.
[0013] It is a further desirable to provide a structural
reinforcement system that has adjustable nailing/mechanical
fastening guides.
[0014] It is additionally desirable provide a structural
reinforcement system that embodies a directional water drainage
system in the structural reinforcement system. It is further
desirable to provide an improved structural reinforcement system
that has improved keying over conventional fiberglass lath.
[0015] It is additionally desirable to provide an improved flexible
lath that has a profile that is three dimensionally uniform to
provide improved keying of mortar and to facilitate a consistent
and repeatable application a scratch coat to provide dimensional
uniformity of the scratch coat.
SUMMARY OF THE INVENTION
[0016] This application relates to the field of structural concrete
substrate. In one embodiment, a lath support system of the
invention utilizes full encapsulation of a lath with a cementitious
material such as concrete or mortar, wherein full encapsulation is
defined as a layer of cementitious material behind the lath and a
layer on top of the lath, forming a scratch coat which is applied
simultaneously,
[0017] The lath support system utilizes strip members that function
as fastener guides, which may be attached to the lath prior to
installation. The lath may be used in conjunction with cementitious
materials including stucco, plaster, tile, countertops, shower
surrounds, manufactured stone and natural stone veneers, brick,
concrete stairs, and other masonry systems.
[0018] As used herein, the term cementitious includes building
materials having the characteristics of cement or mortar and
include plaster, stucco, concrete, shotcrete, gunite, and may
include adhesives, The system of the invention may be used with
other materials such as polymers, or chopped fiber reinforced
materials, and composite structures.
[0019] The invention includes a stripping system and fastener guide
that utilizes a plurality of strip members, preferable constructed
of a compressible material. The strip members may be applied to a
back side of the lath material. The strip members are used to space
the lath away from a support structure, which allows for adjustment
of the thickness of the layer of cementitious material behind the
lath, i.e., the "base layer" or, alternatively, allows for an area
to allow for water to drain. In one embodiment, when cementitious
material is applied to the lath, the cementitious material flows
through the lath. Strip members are used as a structural spacer.
Therefore, the cementitious backing material will be as thick as
the strip members. Methods of applying cementitiuos material
include hand troweling and mechanical application.
[0020] To secure the lath to a support system, such as sheathing,
which may be covered by a water/vapor barrier, fasteners are
typically used. Typical fasteners include staples or nails,
although other fasteners may be used.
[0021] In another embodiment, a first water/vapor barrier is
attached to a back of the lath. Strip members are attached to the
water/vapor barrier. A second water/vapor barrier may be attached
to sheathing or to the back of the strip members. The first
water/vapor barrier functions as a mortar stop to prevent mortar
from migrating to a back side of the lath. The strip members create
an open space to facilitate drainage. The strip members also
perform a gasket-like function by sealing around the fasteners to
prevent water from migrating around the fasteners into
communication with the sheathing.
[0022] The flexible strip members act as nailing guides for the
fasteners. The closer the strip members are spaced, the greater the
structural strength becomes, proportional to the amount of
fasteners that are used to secure the lath.
[0023] A plurality of strip members may be adhered to the back side
of the lath. The strip members function as fastener guides and are
provided to direct where the fasteners should be placed. The
distance between the strip members may be adjusted as necessary to
comply with local and national building codes for attachment
guidelines, e.g., 16 in on center, 24 inches on center, 12 in on
center, etc., according to applicable building code standards.
[0024] The strip members may be used in connection with a variety
of materials including but not limited to the masonry industry,
e.g., tile, countertops, shower surrounds, manufactured stone and
natural stone veneers, brick, concrete stairs, The strip members
may also be used with other masonry systems.
[0025] The nailing strip members may be made of any suitable
material that provides adequate gasket, shock absorbing, water
channeling and thickness properties. A preferred material for the
strip members of the adjustable strip system is a medium density
foam, such as EVA (Ethel Vinyl Acetate). Although EVA is currently
the material of preference, other materials could be used including
silicone, acrylics, foamed or unfoamed, or any other material that
has the desired properties. Open celled foam may also be used, but
open celled foam is not ideal because it has inferior gasket
sealing properties and inferior water channeling capabilities. EVA
is preferred because it is a closed cell foam that provides
gasket-like sealing properties when anchors or fasteners perforate
the water barrier. The foam strip members protect the anchoring
device from corrosion due to water exposure and due to concrete
alkaline environments.
[0026] Strip members are also used as impact reducers for
protecting the lath from fastener installation related to impacts
which are particularly damaging when pneumatic anchoring systems
are used to apply the fasteners. When the fibers that make up a
non-metallic lath are impacted and bent, e.g., from impact trauma
from staples, nails or other fastening devices, the structural
integrity of the non-metallic lath is compromised.
[0027] The nailing strip members of the flexible stripping system
are used as impact or stress point reducing elements to reduce
impact or stress resulting from the fastening process. The impact
absorbing nature of a medium density foam prevents fibers that make
up a non-metallic lath from being damaged, i.e., the foam protects
both mechanical strength degradation due to fiber fractures, and
helps to preserve the zirconium dioxide coating from being damaged
by impact associated with the anchoring processes.
[0028] Most polymer and fiber materials undergo degradation of
strength upon blunt force impact such as applied by pneumatic
anchoring systems or by anchoring by hand. For example, fiberglass
has a high tensile strength but its individual properties are still
based on glass material properties. When fiberglass undergoes
impact or extreme stress on a point, the tensile strength of this
fibrous material can be reduced up to 80% of its original strength.
When looking at non-metallic lath systems that incorporate plastics
with fibers and plastics without fibers, the degradation of
non-metallic materials are similar to the above mentioned fiber
damage using pneumatic anchoring systems. The innovation of a
flexible stripping anchoring guide will reduce impacts and stress
points caused by blunt force trauma of an anchoring system,
therefore protecting the structural integrity of the lath system at
the anchoring point. The flexible stripping system and nailing
guide allows for kinetic energy absorbance and pressure point
elongation caused by the anchoring system to be absorbed by the
flexible stripping system.
[0029] The use of strip members allows the thickness of the base
layer of cementitious material to be controlled by the thickness of
the strip member. Different thicknesses are available for differing
strength applications on the fundamental principals that the
thicker the concrete structure, the stronger the substrate. The
capability of adjusting the thickness and spacing of the strip
members allows for tailoring of structural strengths based on
architectural loads and international building codes.
[0030] In applications where nailing guides are not used, and the
anchoring devices are applied directly to the substrate, the lath
can be damaged and the coatings corrosive protection may be
removed. When mesh fibers are impacted and bent due to blunt force
trauma from staples, nails or other fastening devices, the
structural integrity of the mesh fibers is compromised
[0031] The flexible nailing guides may be applied to the lath by
the manufacturer with adhesive. The flexible nailing strip members
prevent any protective coating on the fiberglass lath from becoming
stripped away, as is common in applications where no strip members
are used. The flexible nailing guides can be moved closer together
as desired to provide compliance with local and national building
codes for attachment guidelines
[0032] In a preferred embodiment, the strip members are adhered to
the lath material, e.g., metallic mesh, non-metallic mesh,
entangled fiber panel, etc., in a generally parallel orientation
along one surface, e.g., the rear surface, of the mesh. The strip
members can be applied either vertically or horizontally.
Typically, the strip members are precut and glued on in individual
pieces when applied vertically or rolled out in long rolls when
applied horizontally, i.e., when applied along the length of the
roll of the mesh. The strip members can be applied by the lath
manufacturer or may be applied directly on the vapor barrier after
the manufacturing process is complete.
[0033] When using a non-metallic mesh as the lath material, a
preferred material for the non metallic mesh of the invention is an
alkali resistant fiberglass. An example material is manufactured by
leno weave. A preferred dimension for the non metallic mesh is four
feet wide, and 75 feet long, although other dimensions may be used
as may be dictated by building code standards. A preferred hole
spacing of the mesh is 6.35 mm. However, the opening sizes may be
adjusted as conditions warrant. For example, if a new mortar
material is developed, e.g., if more acrylic binders or polymers
are added or substituted, and the viscosity goes down, the openings
of the mesh will need to be reduced in size to better hold the
material in the keys of the mesh. Alternatively, if the industry
chooses to go with a chopped fiber mortar or material, the
viscosity will go up, and the opening size of the structural
reinforcement system may need to be increased to allow the material
to key properly.
[0034] When using a mesh, the limitations of the ability of the
cementitious material to flow through the mesh system are believed
to be directly proportional to the grid size of the mesh. The
smaller grid sizes, such as 5 mm, resulted in air voids in the base
layer of the cementitious material, which resulted in an
inconsistent base layer. An extreme grid size, having a grid size
the size of chicken wire let the cementitious material roll out of
the mesh, as there was not enough grid surfaces in place, making
the troweling of the scratch coat twice as long, thus increasing
the labor costs.
[0035] A preferred mesh has a mesh opening size of 6.35
mm.times.6.35 mm, is lightweight, weighing only 25 pounds per 300
square foot roll. In contrast, 300 square foot of metal lath would
be equal to 17 sheets, which weighs approximately 85 pounds and is
therefore difficult for one person to handle or carry.
[0036] When non-metallic mesh is used, the non-metallic mesh can be
cut to length by using a box blade, a pocket knife or even
scissors. In contrast, metal lath must to be cut with tin snips or
with a grinder. The ease of cutting around outlets, windows, doors
and other obstacles when using the mesh of the invention is a
substantial improvement over metal lath. Applying the non-metallic
lath is safer for the handler of the material as compared to metal
lath, which is very sharp and dangerous and can slice the skin very
easily.
[0037] In another embodiment of the invention, a non-metallic lath
is constructed of entangled filament mounted on a fabric backing.
An example of this material is Acousti-Mat.RTM. 3, available from
Maxxon.RTM. Corporation (920 Hamel Road, PO Box 253, Hamel, Minn.
55340). In this embodiment, cementitious material is applied to the
entangled filament. Strip members may be applied to a rear surface
of the fabric backing to create a drain space for water.
[0038] In either embodiment, in a preferred application, the strip
members are 6.35 mm thick (1/4 inch), 12.7 mm (0.5 inches) wide
with a distance between strip members of 15 cm (6 inches center to
center).
[0039] The lath is preferably applied over a moisture/vapor layer,
e.g., 30 lb tar paper, stapled with fasteners, e.g., galvanized
staples that have a one inch crown and that are at least one inch
long and more preferably 11/4 inches long. The fasteners, such as
nails or staples, pass through the strip members, i.e., the strip
members are used as a fastening guide. A mortar scratch coat may
then be hand troweled onto the lath. A finish coat may then be
applied after the scratch coat is dry.
[0040] An additional embodiment of the structural reinforcement
system of the invention utilizes a water/vapor barrier. Adjustable
nailing/anchoring strip members are adhered to back of the mesh.
The mesh with the nailing guides attached is then applied over a
moisture barrier, which is already attached to the alkali resistant
mesh. The mesh and the moisture barrier may then be
fastened/mechanically anchored to the sheathing/support structure.
In a further alternate embodiment, a second water/vapor barrier is
attached directly to the sheathing or to the back of the strip so
the strip is sandwiched between two layers of paper.
[0041] The nailing strip members can be mechanically fastened to
the mesh. Alternatively, the nailing strip members can have a peel
off adhesive for adhering to the vapor barrier, then later
mechanically fastened. For improved water drainage channeling, the
nailing strip members may be adhered directly to the water/vapor
barrier.
[0042] In a preferred embodiment, the adjustable nailing/anchoring
strip members are adhered to back of the mesh. The strip members
are then applied over the moisture barrier, which has been
previously installed. Then the lath is fastened/mechanically
anchored to the sheathing/support structure.
[0043] Non-metallic mesh has advantages with respect to prior art
metal systems, which had to be hung in a correct orientation to
function properly. The mesh of the current invention can be hung in
any orientation, which makes installation at least 40% faster.
[0044] A non-metallic mesh provides greater coverage per roll as
compared to metal lath. The rolls of non-metallic mesh are 4 feet
wide, as opposed to the 27 in for metal lath. A mason can carry a
roll of non-metallic lath up scaffolding and attach the
non-metallic lath at the top of the substrate and let the rest of
the roll of lath fall to the ground. The suspended mesh may then be
fastened to the substrate. In contrast, metal lath is cumbersome,
heavy, and dangerous to transport to great heights.
[0045] The installation of a non-metallic lath saves on
installation time, thus saving on labor costs. The labor savings is
at least 50% over the metal for example a manufactured stone
installer, can save over 50% in labor in residential projects, and
in some commercial projects that have long straight runs, 80%. The
minimum savings on installation is 50%.
[0046] The scratch coat is easy to apply on a fiberglass mesh lath
material, wherein the troweling of the mud glides over the
fiberglass surface. The installation of the strip members of
flexible stripping system and nailing guide allow more cement to be
pushed behind the non-metallic mesh to create a stronger substrate
since the non-metallic mesh becomes embedded between the layers of
cementitous material.
[0047] In one embodiment, single sided or double sided self
adhering flexible nailing guides may function as a drainage system.
The drainage system is constructed by adhering the flexible nailing
guides to the water/vapor barrier before mechanically fastening or
anchoring or installing the lath. The flexible nailing guides may
be provided with adhesive surfaces or may be without an adhesive
surface. The flexible nailing guides may be previously installed
onto the lath wherein the lath and attached nailing guides are
mechanically anchored to the structural framing at the same time.
In one preferred embodiment, drainage strip members may function as
drainage guides. The draining guides may be installed at an angle
to horizontal to direct flow of water as desired, e.g., angled
drain guides may be placed above a window to prevent pooling of
water on horizontal wall structures.
[0048] In another embodiment of the structural reinforcement
system, the water/vapor barrier can be applied to the lath to form
a composite system.
[0049] The strip members, when used as a drainage guide, may be
constructed of open celled foam to absorb and redirect water flow
to facilitate water drainage. These drainage guides can be applied
to the vapor/water barrier prior to the lath being applied or can
be directly adhered to the lath from the manufacturer.
[0050] The system of the present invention incorporates an
adjustable thickness flexible\mesh system which increases the
amount of cementitious material that can pass through the flexible
mesh. The non metallic mesh support substrate system of the
invention utilizes a stripping system wherein the thickness of the
stripping may be adjusted to match the thickness of the
cementitious substrate. The thickness of the stripping may also be
adjusted as desired. The strength of the cementitious substrate is
proportional to the thickness of the flexible stripping system and
anchoring guide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] FIG. 1A is a partial cutaway view of one embodiment of a
structural reinforcement system of the invention wherein a mesh is
used as a lath material having a plurality of strip members
separating the mesh from a moisture/vapor barrier and a second
moisture/vapor barrier between the strip members and the mesh
wherein the second moisture/vapor barrier functions as a mortar
stop.
[0052] FIG. 1B is a partial cutaway view of one embodiment of a
structural reinforcement system of the invention wherein a mesh is
used as a lath material having a plurality of strip members
separating the mesh from a moisture/vapor barrier.
[0053] FIG. 2 is a partial cutaway view of one embodiment of a
structural reinforcement system of the invention wherein a mesh is
used as a lath material having a plurality of strip members
separating the mesh from a support structure.
[0054] FIG. 3 is an enlarged view of the lath portion of FIG.
1.
[0055] FIG. 4 is a top view of the lath portion shown in FIG.
3.
[0056] FIG. 5 is a side view of the lath portion of FIG. 3.
[0057] FIG. 6 is a side view of an alternate embodiment of the
structural reinforcement system including open celled absorbent
strip members.
[0058] FIG. 7 is a partial cutaway view of another embodiment of a
structural reinforcement system of the invention wherein a sheet of
entangled filament is used as a lath having a plurality of strip
members separating the entangled filament sheet from a
moisture/vapor barrier.
[0059] FIG. 8 is a perspective view of a section the entangled
filament of FIG. 7.
[0060] FIG. 9 is a front view of a housing structure showing
installation of sheathing and a plurality of strip members affixed
thereto when the strip members comprise nail guides and drainage
strip members.
[0061] FIG. 10 is an enlarged view of the non-metallic lath of
FIGS. 1-6 showing a fastener penetrating a strip member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] Referring now to FIG. 1B, the structural reinforcement
system 10 of the invention is shown. Structural reinforcement
system 10 is affixed to support structure 12. Support structure 12
typically is made up of a plurality of studs 14 which may be
covered with sheathing 16. An example of sheathing 16 is oriental
strand board (OSB). A lath 18 is located adjacent to support
structure 12. Lath 18 has a front surface 20 and a rear surface
22.
[0063] In one embodiment (FIGS. 1A-6) lath 18 is a mesh structure
23. Mesh structure 23 may be a metal lath or a non-metallic lath.
In the embodiment wherein lath 18 is a non-metallic lath, mesh
structure 23 includes a first group of a plurality of strands 24
(best shown in FIGS. 3-6) that are generally parallel to one
another, e.g., horizontal strands. Mesh structure 23 further
includes a second group of strands 26 that are generally parallel
to one another and transverse to the first group of plurality of
strands 24, e.g., vertical strands. First group of strands 24 and
second group of strands 26 are woven together or heat sealed or
otherwise generally secured to form a mesh or netting. The
preferred construction of mesh structure 23 is a leno weave. A
preferred mesh structure 23 has a zirconium dioxide content of at
least 14.5% and a weight of 300 grams per square meter. In a
preferred embodiment, each of strands 24, 26 are made up a
plurality of individual fiberglass fibers. Although the strands 24,
26 are shown generally parallel to one another, it should be
understood that other orientations are also possible.
[0064] In a preferred embodiment, the first group of a plurality of
strands 24 that make up mesh structure 23 are given a slight twist
so that there is a slight bit of cupping in the strand on the outer
surface of mesh structure 23. This cupping mimics the bow that is
usually found on metal lath. In many applications where lath 18 is
used there is, for example, a support structure 12, such as a
series of studs 14 that form a matrix for receiving sheets of
sheathing 16. Over sheathing 16 is usually placed a vapor barrier
32 such as Tyvek.RTM. or tar paper or other sheet material. Over
the sheathing 16 or the sheet material lath 18 is placed. Lath 18
is secured to the support structure 12 by any suitable fastener 34
such as nailing tacks, staples, screws or other fasteners that are
accepted by national building code standards. In prior art
applications lath 18 is secured directly to the sheathing 16. Since
lath 18 is generally in contact with the sheathing 16 or sheet
material, there is not a great deal of space, if any, between lath
18 and the sheets or sheaths 16. A problem that arises is that the
absence of space behind the lath 18 makes it difficult for a
cementitious material 29, such as stucco, plaster, mortar and/or
adhesive to key properly to the lath 18.
[0065] In a further embodiment (FIGS. 7, 8), lath 18 is a
non-metallic entangled filament 27 mounted on a fabric backing 28.
An example of this material is Acousti-Mat.RTM. 3, available from
Maxxon.RTM. Corporation (920 Hamel Road, PO Box 253, Hamel, Minn.
55340).
[0066] Front surface 20 of lath 18 is the surface to which
cementitious material 29 (FIGS. 1A, 1B, 2, 7) is to be applied.
Rear surface 22 preferably has one or more strip members 30 affixed
thereto and may include a water/vapor barrier 32. Strip members 30
are preferably formed of a compressible material such as EVA, foam,
or polystyrene. When structural reinforcement system 10 is
assembled, strip members 30 separate lath 18 from support structure
12 to which lath 18 is secured. Typically, strip members 30 have an
adhesive that secures strip member 30 to rear surface 22 of lath
18. Preferably, the adhesive is one that permits strip members 30
to be readily removed from contact with lath 18 so that spacing of
strip members 30 can be adjusted as needed.
[0067] In the embodiment wherein mesh structure 23 functions as
lath 18, a portion of cementitious material 29 passes through mesh
structure 23 to form a base layer and for encapsulating mesh
structure 23.
[0068] Cementitious material 29 encapsulates the mesh structure 23,
with the space between the mesh structure 23 and sheathing 16 or
water/vapor barrier 32 allowing the full encapsulation of mesh
structure 23 in the cementitious material 29. The spacer provided
by strip members 30 permit more of the cementitious material 29 to
pass through the mesh structure 23 than is normally achieved.
[0069] Structural reinforcement system 10 may further include a
water/vapor barrier 32 adjacent to support structure 12. In a
preferred embodiment, water/vapor barrier 32 is located between
support structure 12 and rear surface 22 of lath 18.
[0070] In some applications, a water/vapor barrier 32, such as a
sheet of tar paper, is placed over sheathing 16 or sheet material.
Lath 18 with optionally attached strip members 30 may be applied
over the sheathing 16. In another version of the current invention
shown in FIG. 1A, a water/vapor barrier 32 is already directly
attached to lath 18 and strip members 30 are attached thereon.
Strip members 30 are applied to a second water/vapor barrier 32A
simultaneously, thereby eliminating an added step of separately the
second said water/vapor barrier 32A.
[0071] Fasteners 34 (FIGS. 1A, 1B, 2, 6, 7 and 10) penetrate the
plurality of strip members 30 for affixing strip members 30 and
lath 18 to support structure 12. When water/vapor barrier 32 is
utilized, fasteners 34 penetrate plurality of strip members 30 and
secure lath 18 and water/vapor barrier 32 to support structure 12.
Lath 18 is preferably applied with fasteners every 6 inches on the
perimeter and every 12 inches on the field.
[0072] Strip members 30 are preferably comprised of a material that
provides a gasket-like water-tight seal around fasteners 34 when
fasteners 34 penetrate strip members 30 for securing lath 18 to
support structure 12. The water-tight seal around fasteners 34 by
strip members 30 functions to seal out moisture and to protect
fasteners 34 from exposure to alkaline substances. Additionally,
the seal formed around fasteners 34 prevents moisture from entering
and penetrating into support structure 12.
[0073] An additional property of strip members 30 is that strip
members 30 are capable of absorbing impacts associated with
installing fasteners 34. Impact absorption by strip members 30
prevents lath 18 from being damaged. Damage which may occur to lath
18 includes structural damage due to impact of installing fasteners
34. Additional damage that may occur during installation of
fasteners 34 is the inadvertent removal of a corrosion resistant
coating on mesh 18.
[0074] Strip members 30 may be attached to support structure 12
before lath 18 is attached to support structure 12. Strip members
30 may also be applied to lath 18. Strip members 30 may be applied
to anything that is used in the construction of the structural
support system 10. For example, strip members 30 may be applied to
building paper or water/vapor barrier 32 and adhered before the
structural support system 10 is constructed. A first sheet of
water/vapor barrier 32 is affixed to lath 18 and functions as a
mortar stop. A second sheet of water/vapor barrier 32A (FIG. 1A) is
affixed to sheathing 16 and is used as a moisture barrier. In this
embodiment, strips 30 are provided to serve spacing and gasket
functions. Strips 30 may be used with metal or non-metallic
embodiments of lath 18.
[0075] Strip members 30 may also be affixed to lath 18 prior to
attachment of lath 18 to support structure 12. Structural
reinforcement system 10 is adjustable in that strip members 30 may
be affixed to lath 18 at desired spacing to meet construction
requirements. Additionally, strip members 30 may be oriented in a
vertical or horizontal configuration as desired.
[0076] Strip members 30 may be used both as fastener guides 35 and
as drainage guides 37 (FIG. 9). Fastener guides 35 are preferably
made up of a closed cell foam material that forms a water-tight
seal around fastener 34. Drainage guides 37 are preferably made up
of an open cell foam that is absorbent. In one embodiment, drainage
guides 37 are oriented so that after lath 18 is attached to support
structure 12 with fasteners 34, drainage guides 37 are
non-horizontal and non-vertical for directing water that passes
behind lath 18 may be directed as desired. As an example, drainage
guides 37 may be located above a window or door in a structure as
shown in FIG. 9 to prevent pooling of liquids above the window or
door.
[0077] Strip members 30 may also be used as a combination of
fastener guides 35 and drainage guides 37 installed in parallel, as
shown in FIG. 6, so that any liquids that are behind lath 18 may be
absorbed and redirected by the open celled foam of the drainage
guides 37. Strip members 30 may be installed, one on top of another
wherein a strip member 30 of closed cell foam is located adjacent
to sheathing 16 or water/vapor barrier 32 and strip members 30 of
open cell foam is located adjacent to mesh 18 so that strip members
30 of open cell foam allow for drainage.
[0078] In practice, the structural reinforcement system 10 of the
invention may be installed by affixing a plurality of strip members
30 to lath 18, such as rear surface 22 of mesh structure 23 or
backing 28 of entangled filament 27. Lath 18 with attached strip
members 30 may then be located on a support structure 12. A
water/vapor barrier 32 may be affixed to support structure 12 or
may be attached to strip members 30 and lath 18 for simultaneous
installation, Alternatively, a first water/vapor barrier 32 may be
attached to a back of lath 18 to function as a mortar stop and a
second water/vapor barrier 32a may be attached to sheathing 16,
[0079] Fasteners 34 are then used to fastening lath 30 to support
structure 12 wherein fasteners 34 pass through strip members 30
before engaging support structure 12. If water/vapor barrier 32 is
used, fasteners 34 will penetrate water/vapor barrier 32 prior to
engaging support structure 12. During application of fasteners 34,
strip members 30 absorb the impact of the fastening process,
thereby protecting said lath 18. Cementitious material 29 may then
be applied to lath 18.
[0080] FIG. 10 shows lath 18 and strip members 30 attached to the
sheathing 16 with fastener 34, e.g., a staple. The strip member 30
functions as a fastener and guide 35 to absorb the impact of
fastener 34 and allows the cementitious material 29 to encapsulate
the mesh structure 23 in a full bed of cementitious material 29.
The webbing of the mesh structure becomes flexed, but the strands
24, 26 are not damaged.
[0081] In the embodiment wherein mesh structure 23 is used as lath
18 is mesh structure 23, a thickness of strip members 30 may be
selected so that space behind mesh structure 23 is also selected,
thereby regulating a thickness of a base layer of cementitious
material 29 that migrates in between mesh structure 23 and support
structure 12.
[0082] In the embodiment wherein entangled filament 27 is used as a
non-metallic embodiment of lath 18, strip members 30 are placed
behind backing 28 of entangled filament 27 to create a void for
allowing moisture to flow between the lath 18 and the cementitious
material 29 without impediment.
[0083] As explained above, fasteners 34 are passed through strip
members 30, which serve as fastener guides 35. Strip members 30
form a seal against fasteners 34 to prevent moisture from passing
around said fastener. Strip members 30 additionally seal fasteners
34 against exposure to alkaline substances that may be present in
cementitious material 29.
[0084] Strip members 30 may be used as drainage guides 37 wherein
strip members 30 are oriented in a non-horizontal and non-vertical
orientating for directing water that passes behind said lath.
Alternatively, Strip members 30 may be constructed of an open
celled foam and placed adjacent to or on top of strip members 30 of
closed cell foam so that the drainage guides 37 function to
redirect water.
[0085] Thus, the present invention is well adapted to carry out the
objectives and attain the ends and advantages mentioned above as
well as those inherent therein. While presently preferred
embodiments have been described for purposes of this disclosure,
numerous changes and modifications will be apparent to those of
ordinary skill in the art. Such changes and modifications are
encompassed within the spirit of this invention as defined by the
claims.
* * * * *