Wall lath with self-furring ridges

Description

This application claims the priority of Provisional U.S. Patent Application Ser. No. 61/932,393 filed Jan. 28, 2014.

FIELD OF THE INVENTION

This invention relates to the reinforcement of viscous materials used in either interior or exterior applications, and more specifically to a lath for accepting and supporting such viscous materials as they are applied and cured to create a finished surface.

BACKGROUND OF THE INVENTION

Stucco, plaster, and similar viscous materials are typically applied to substrates such as plywood sheathing or cementitious materials. Historically, metal laths were secured to vertical substrates by nails or similar fasteners and such laths helped secure the viscous plaster and support the plaster prior to its drying and curing to form a solid surface. However, as metal lath was prone to corrosion by the alkaline plaster, thereby creating unsightly stains in the wall surface, plastic laths have become an acceptable substitute for metal.

Various plastic laths have been proposed for the application of plaster to a substrate. Plastic laths typically include a flexible planar structure that includes a plurality of openings therein for accepting the viscous materials. They are typically secured to the substrate, after which the stucco or plaster in a flowable state is applied thereto. The plurality of openings in the plastic lath enable the viscous material to seep through and make contact with the substrate, which after curing enables bonding of the plaster to the lath and to the substrate.

Although various flexible laths have been proposed, they typically do not provide the desired depth and the desired contact by the lath with the substrate to achieve proper bonding. Accordingly, it would be advantageous to provide a plastic lath that maximizes contact of the viscous materials with the substrate and which furthermore enables the application of the proper desired depth of viscous material applied to the substrate.

SUMMARY OF THE INVENTION

The present invention comprises a lath for use in applying plaster to a substrate. The lath includes a plurality of crossing members forming a substantially planar lattice-like structure with a plurality of openings therein. The crossing members include a plurality of first elongate members extending in a first direction, a plurality of second elongate members that extend laterally and substantially transversely to the first elongate members, and a plurality of self-furring ridges also extending laterally and substantially transversely to the first elongate members and substantially parallel to and interspersed with the second elongate members.

OBJECTS AND ADVANTAGES

Several advantages are achieved with the lath of the present invention, including:

• • (1) The lath includes self-furring ridges provide exceptional keying for stucco or plaster.
  • (2) The lath includes a ribbed surface on each of the self-furring ridges.
  • (3) The lath eliminates the need for furring members to establish a desired depth from the substrate.
  • (4) The lath is constructed of a flexible plastic that makes it impervious to rust or corrosion when used with an alkaline-based plaster or stucco system.
  • (5) The lath establishes proper reinforcement for the plaster or stucco layer applied to the substrate.
  • (6) The lath includes an optimal amount of keys or openings per given area to maximize contact of the viscous materials with the substrate.
  • (7) The lath is lightweight and impervious to sand and to chemicals found in portland-based stucco or plaster.

These and other objects and advantages of the present invention will be better understood by reading the following description along with reference to the drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Reference is made herein to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 is an isometric view of a lath in according to the present invention.

FIG. 2 is a top plan view of the lath of FIG. 1.

FIG. 3 is a sectional view of the lath taken along line 3-3 of FIG. 2.

FIG. 4 is a detail view of a portion of the lath depicted in FIG. 2.

FIG. 5 is a sectional view of the lath of the present invention in contact with a substrate and with plaster applied thereto.

FIG. 6 is a detail view of a portion of the section depicted in FIG. 3.

FIG. 7 is a sectional view of the lath taken along line 7-7 of FIG. 2.

DETAILED DESCRIPTION

The present invention comprises a lath for use in applying plaster to a substrate. The lath includes a plurality of crossing members forming a substantially planar lattice-like structure with a plurality of openings therein. The crossing members include a plurality of first elongate members extending in a first direction, a plurality of second elongate members that extend laterally and substantially transversely to the first elongate members, and a plurality of self-furring ridges also extending laterally and substantially transversely to the first elongate members and substantially parallel to the second elongate members.

With reference to FIGS. 1 and 2, there is shown a lattice-like lath 20 according to the present invention. The lath includes a plurality of elongated first elongate members 22 extending in a first direction and a plurality of narrow second elongate members 24 extending laterally and substantially transversely to and intersecting the first members 22. The second elongate members 24 intersecting the first elongate members 22 at a substantially constant angle θ. The lath 20 also includes a plurality of self-furring ridges 26 extending laterally and substantially transversely to the first members 22 and substantially parallel and interspersed between the second members 24. A plurality of openings or keys 28 are formed by the intersecting first 22, second 24, and self-furring ridges 26. The angle θ of intersection between the second elongate members 24 and first elongate members 22 is preferably between 75 and 90 degrees.

In the preferred embodiment, each self-furring ridge 26 is most preferably separated by two or more second members 24. As shown in FIG. 2, as viewed from the top of the lath, the second members 24 are substantially narrower than the self-furring ridges 26.

Referring to FIG. 3, the plurality of first members 22 form a substantially planar outer surface 30 on the lath 20. The self-furring ridges 26 extend a substantially longer distance D1 from the inner end 31 of the first members 22 than the distance D2 the second members 24 extend from the inner end 31. Each self-furring ridge 26 includes tapered sides 34 and an end 36. The sides of the self-furring ridge 26 taper from a wide width at the juncture 37 with the first member 22, to a narrow width at the end 36.

With reference to FIG. 4, a first filet 38 is formed at the juncture of second member 24 with first member 22 and a second filet 40 is formed at the juncture or joint 42 of the self-furring ridge 26 and the first member 22. The filets 38 and 40 increase the strength of the lattice-like lath 20 at the joints 42.

Referring to FIG. 5, the lath 20 is used to provide a structure for plaster to adhere to, such as on a vertical wall. The lath 20 is first positioned on the wall with ends 36 of third members or self-furring ridges 26 pressed flush against the substrate 44. The lath 20 is secured to the substrate 44 with nails or similar fasteners (not shown). Plaster 46 is then spread on the lath by trowel, spraying, or similar means. Plaster spreads through the openings 28 in the lath and fills the spaces between the first 22, second 24, and self-furring ridges 26. After drying, the lath becomes an integral part of the plaster or stucco layer 46.

The long self-furring ridges 26 provide a substantial standoff from the substrate thereby creating a large volume to be filled with plaster. By separating each self-furring ridge 26 with two or more short second members 24, a substantial reduction in cost of production is achieved over laths including equally sized crossing members. The amount of plastic required for constructing the lath is lessened substantially by the lesser number of crossing members required to achieve the standoff.

With reference to FIG. 6, the first members 22 and the second members 24 preferably each include a thickness D3 of 0.04 to 0.06 inch. Most preferably, the thickness D4 of the self-furring ridges 26 is preferably at least 0.20 inch. Thus the self-furring ridges 26 are 3 to 5 times the thickness of the second members.

As shown in FIG. 7, each self-furring ridge 26 includes a series of ribs 50 and troughs 52 along the end 36 of the self-furring ridge 26. First members 22 include arcuate outer surfaces 54. The end 36 of the self-furring ridge 26 includes a ribbed surface 56 and arcuate outer surfaces 54 of first members 22 form an outer side 58 of the lattice-like lath 20.

To operate the invention, the ribbed surface 56 of the lattice-like lath 20 is placed against the outer surface of the substrate 44 as shown in FIG. 7. The ribs 50 of ribbed surface 56 provide contact with the substrate 44 and position first members 22 away from the substrate. The lattice-like lath 20 is then secured to the substrate 44 by nails or similar fasteners. Adjacent pieces of lath may be secured together by wire ties or cable ties. The ribbed surface 56 holds the outer side 58 of the lath 20 at the proper distance from the substrate 44 to aid in keying of stucco or plaster to the lath.

The lath 20 of the present invention is preferably constructed of plastic, is flexible, and may be flexed across its length or width. According to the present invention, a length of lath may be rolled into a roll for shipment and storage prior to shipment to a job site. With reference to FIG. 1, most preferably the lath includes between 11,000 and 12,000 openings or keys 28 per square yard.

The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.