WO2012062722A1

WO2012062722A1 - Trim bead and stucco systems, including same

Info

Publication number: WO2012062722A1
Application number: PCT/EP2011/069588
Authority: WO
Inventors: William F. Egan; David Smith
Original assignee: Construction Research & Technology Gmbh
Priority date: 2010-11-08
Filing date: 2011-11-08
Publication date: 2012-05-18
Also published as: CN103201442A; US20120110936A1; CA2816036A1; BR112013011366A2; EP2638221A1; RU2013126193A; JP2013545910A

Abstract

A trim bead for a building wall incorporates an outwardly extending flange portion to provide a mechanical key for a layer of exterior finishing coatings, such as stucco coatings. The trim bead may be used in stucco systems for exterior building walls that employ continuous thermal insulation over the building wall substrate.

Description

TRIM BEAD AND STUCCO SYSTEMS, INCLUDING SAME

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of United States Provisional

Application for Patent Serial Number 61/411,125 filed November 8, 2010, which is hereby incorporated by reference.

BACKGROUND Exterior stucco or cement plaster, as it is commonly known, is installed on commercial as well as residential buildings and can be applied over a variety of substrates such as masonry as well as framed/sheathed wall assemblies. Depending upon the type of substrate, an intervening layer of a water resistive barrier and lath or plaster base, which serves as a mechanical key for the stucco, is applied prior to the application of the stucco.

There are two common types of stucco which are commonly referred to as One Coat Stucco which generally consists of a 3/8 to 1/2 inch thick stucco and Three Coat or traditional stucco which generally consists of 1/2 to 3/4 inch thick stucco. The stucco is either hand troweled or spray applied to the substrate or lath (if used). Trim accessories, also known in the building and construction industry as trim bead, which are fabricated from metal or plastic, are used in conjunction with stucco to serve as a gauge for the stucco thickness and/or as a termination or stopping point for the stucco. A finish coat or paint/coating is applied over the dry/cured stucco to provide the final appearance.

Thermal insulation, when used with stucco clad walls, is most commonly achieved by installing one of several types in the stud or wall cavity. In some cases, limited thicknesses (generally no greater than 1 1/2") of a thermal insulation board, which is generally a foam plastic such as Expanded Polystyrene, is installed continuously over the substrate prior to the application of the lath. Historically, continuous thermal insulation board has been used more often with the One Coat Stucco systems than with three coat stucco systems. Due to recent energy codes such as the IECC (International Energy Conservation Code), as well as standards such as ASHRAE (American Society of Heating, Refrigerating, and Air- Conditioning Engineers), there is an increasing demand in many cases to use Stucco with continuous thermal insulation applied over the substrate at greater thicknesses than the 1 1/2" which has traditionally been used in the past. In fact, continuous insulation thicknesses of 4" or more may be needed to satisfy existing or anticipated energy code requirements. As the thickness of the continuous insulation board increases, it can change the geometry, profile, complexity and detailing of stucco wall assemblies specifically as it relates to satisfying conditions such as fire requirements, drainage, and final aesthetic appearance. Trim accessories, originally intended for use with stucco that did not contain continuous insulation or possibly accommodated thinner (1 ½" thick or less) continuously insulated systems often can not accommodate the thicker continuously insulated systems. Current commercially available trim accessories, which for various technical as well as aesthetic reasons, do not sufficiently satisfy the thicker continuous insulation systems. As a result, there is a need to develop a new type of trim accessory that will better accommodate continuously insulated stucco systems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of one illustrative embodiment of the trim bead.

FIG. 2 is a bottom perspective view of the illustrative embodiment of the trim bead shown in FIG 1.

FIG. 3 is an end view of one illustrative embodiment of the trim bead.

FIG. 4 is end view of one illustrative embodiment of a building wall using the trim bead shown in FIGS. 1 -3.

FIG. 5 is an enlarged fragmentary view of the building wall and trim bead shown in FIG.

4.

DETAILED DESCRIPTION

Provided is a trim bead, which can be fabricated from various materials, that will address the unique needs of stucco systems that incorporate various thicknesses of continuous, thermal exterior insulation. The trim bead will enable the continuous insulation to be sufficiently encapsulated with stucco, provide a means to drain incidental moisture as would be needed at heads, foundation, as well as other similar conditions and openings, provides a mechanical key for the stucco, a ground or thickness gauge, and is aesthetically pleasing since it enables more of the stucco (and less of the trim bead) to be visible. If necessary, depending upon the type and requirements of the construction, encapsulation of the continuous thermal insulation by the stucco can provide fire protection.

The trim bead is for use in an exterior building wall. The trim bead comprises spaced- apart front and rear walls, a bottom wall extending between and connecting the front and rear walls, and a flange portion extending substantially horizontally from the front wall. The flange of the trim accessory includes a plurality of opening communicating through the thickness of the flange.

The trim bead may comprise a polymer material, a metal material, a metal alloy material, or a composite material. According to certain embodiments, the bottom wall comprises at least one weep hole to drain water and other incidental moisture from the wall to the external environment. The rear wall may comprise at least one opening communicating at least partially through the thickness of the rear wall to engage a mechanical fastener to fasten the trim bead to the building wall substrate. In the event that the trim bead is utilized is a jamb area of an opening in the building structure, it does not require a weep hole for drainage purposes.

The flange is provided with a plurality of openings communicating through the thickness of the flange to hold an exterior finishing material, such as stucco. The openings may be formed in metal or metal alloy flanges by perforating, stamping, or expanding the material of the flange of the trim bead. According to alternative embodiments, the trim bead may be made from a polymer material and the openings may be formed in the polymer material. The openings allow the exterior finishing material, such as stucco, to communicate through the thickness of the flange. In the construction industry, the term "keying" is used to describe an exterior finishing material communicating through an opening in an object.

In certain embodiments, the flange may comprise a mesh, a diamond mesh, or a ribbed structure.

Also provided is an exterior finish system for building walls. The exterior finish system comprises optionally a weather resistive barrier, a trim bead, an insulation layer, a reinforcement layer for exterior finish materials, and at least one layer of an exterior finishing coating applied to the reinforcement layer and the flange of the trim bead. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall.

Also provided is a stucco system for building walls. The stucco finish system comprises optionally a weather resistive barrier, a trim bead, an insulation layer, a lath attached to the insulation layer, and at least one layer of a stucco coating applied to the lath, the insulation layer, and to the flange of the trim bead. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall.

An exterior building wall is also provided. The exterior building wall comprises a frame having an exterior surface. A trim bead is attached to the exterior surfaces of the frame. A weather resistive barrier is optionally attached to said exterior surface of said frame, prior to the trim bead. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of openings communicating through the thickness of the flange. An insulation layer is adjacent the trim bead and attached the frame, a reinforcement layer attached to the insulation layer, and at least one layer of an exterior finishing coating is applied to the insulation layer and the flange of the trim bead. According to certain illustrative embodiments, the exterior building wall comprises a frame having an exterior surface. A trim bead is attached to the exterior surfaces of the frame. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim accessory includes a plurality of opening communicating through the thickness of the flange. An insulation layer is adjacent the trim bead and attaches from the building wall, a lath is attached over the insulation layer, and at least one layer of a stucco coating is applied to the insulation layer and the flange of the trim bead.

According to certain illustrative embodiments, the exterior building wall comprises a frame having an exterior surface. A building wall substrate is attached to the exterior surface of the frame. A trim bead is attached to the exterior surfaces of building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of opening communicating through the thickness of the flange. An insulation layer is attached to the building wall substrate, a reinforcement layer is attached to the insulation, and at least one layer of an exterior finishing coating is applied to the reinforcement layer, the insulation layer, and the flange of the trim bead.

According to certain illustrative embodiments, the exterior building wall comprises a frame having an exterior surface. A building wall substrate is attached to the exterior surface of the frame. A trim bead is attached to the exterior surfaces of building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of opening communicating through the thickness of the flange. An insulation layer is attached to the building wall substrate, a lath is attached to the insulation layer, and at least one layer of a stucco coating is applied to the lath, the insulation layer, and flange of the trim bead.

According to further illustrative embodiments, the exterior building wall comprises a frame having an exterior surface. A building wall substrate is attached to the exterior surface of the frame. A weather resistive barrier is attached over the building wall substrate. A trim bead is attached to the exterior surfaces of building wall substrate. The weather resistive barrier overlays the vertical rear wall of the trim bead that is positioned adjacent the exteriorly facing surface of the building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of openings communicating through the thickness of the flange. An insulation layer is adjacent the trim bead, and attaches to the building wall substrate. A reinforcement layer is attached to the insulation layer. At least one layer of an exterior finishing coating is applied to a reinforcement layer or the insulation layer and the flange of the trim bead.

According to further illustrative embodiments, the exterior building wall comprises a frame having an exterior surface. A building wall substrate is attached to the exterior surface of the frame. A weather resistive barrier is attached over the building wall substrate. A trim bead is attached to the exterior surfaces of building wall substrate. The weather barrier overlays the vertical rear wall of the trim bead that is positioned adjacent the exteriorly facing surface of the building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim accessory includes a plurality of opening communicating through the thickness of the flange. An insulation layer is adjacent said trim bead and attached to the building wall substrate, a lath is attached to the insulation layer, and at least one layer of a stucco coating is applied to the insulation layer and the flange of the trim bead.

A process for finishing an exterior building wall is also provided. The process for finishing an exterior building wall comprises attaching a trim bead to the exterior surfaces of a framed wall. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of opening communicating through the thickness of the flange, attaching an insulation layer to the building wall frame, and applying a layer of an exterior finishing material coating to the surfaces of the insulation layer and the flange of the trim bead.

According to certain illustration embodiments, the process for finishing an exterior building wall comprises attaching a trim bead to the exterior surfaces of a framed wall. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of openings communicating through the thickness of the flange, attaching an insulation layer to the building wall frame, attaching a lath to the insulation, and applying a layer of a stucco coating to the surfaces of the lath, or the insulation layer and the flange of the trim bead.

According to further illustrative embodiments, the process for finishing an exterior building wall comprises attaching a building wall substrate to the exterior surfaces of the framed wall. A trim bead is then attached to the exterior surfaces of the building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of openings communicating through the thickness of the flange, attaching an insulation layer to the building wall substrate, and applying a layer of an exterior finishing material coating to the surfaces of the insulation layer and the flange of the trim bead.

According to further illustrative embodiments, the process for finishing an exterior building wall comprises attaching a building wall substrate to the exterior surfaces of the framed wall. A trim bead is then attached to the exterior surfaces of the building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of opening communicating through the thickness of the flange, attaching an insulation layer to the building wall substrate, attaching a lath to the insulation, and applying a layer of a stucco coating to the lath which has been installed over the insulation layer and the flange of the trim bead. According to further illustrative embodiments, the process for finishing an exterior building wall comprises attaching a building wall substrate to the exterior surfaces of the framed wall. A weather resistive barrier is attached over the building wall substrate. A trim bead is then attached to the weather resistive barrier-covered building wall substrate. The weather resistive barrier is applied over a portion of the vertical rear wall of the trim bead that is positioned adjacent the exteriorly facing surface of the building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of opening communicating through the thickness of the flange, attaching an insulation layer to the building wall substrate, and applying a layer of an exterior finishing material coating to the surfaces of the insulation layer and the flange of the trim bead.

According to further illustrative embodiments, the process for finishing an exterior building wall comprises attaching a building wall substrate to the exterior surfaces of the framed wall. A weather resistive barrier is attached over the building wall substrate. The weather resistive barrier is applied over at least a portion of the vertical rear wall of the trim bead that is positioned adjacent the exteriorly facing surface of the building wall substrate. A trim bead is then attached to the weather resistive barrier-covered building wall substrate. The trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall. The flange of the trim bead includes a plurality of opening communicating through the thickness of the flange, attaching an insulation layer to the building wall substrate, attaching a lath to the insulation layer, and applying a layer of a stucco coating to the lath which has been installed over the insulation layer and the flange of the trim bead.

The building wall substrate, without limitation, may be selected from plywood sheathing, wafer board, particle board, oriented strand board, cement board, gypsum board, poured concrete, concrete block, and masonry block. In one embodiment, the building wall substrate is a layer of plywood sheathing. According to other embodiments, the building wall substrate may be a layer of masonry block. According to certain embodiments, the weather resistive barriers may include water resistive barriers and other well known and industry accepted sheet materials or factory applied materials that resist the transmission of water therethrough and control the transmission of moisture vapor and air therethrough. Without limitation, examples of suitable sheet materials include SENERFLASH commercially available from BASF Corporation - Wall Systems (Jacksonville, FL, USA).

Non-woven sheets of spun-bonded high density polyethylene fibers are commercially available from E.I. DuPont de Nemours & Co. , Inc. (Wilmington, Delaware) under the trademarks Tyvek® HomeWrap™, Tyvek® StuccoWrap™ and Tyvek® CommerciaiWrap™. The non-woven structure provides excellent resistance to water and air penetration. In addition, the non-woven structure has excellent strength and tear resistance. Alternatively to the use of the paper or sheet materials as the secondary weather barrier, a fluid applied weather resistive barrier may be used. Without limitation, any only by way of illustration, suitable roller, spray, or trowel applied secondary water resistive barriers may include those water barrier materials commercially available from BASF Corporation - Wall Systems (Jacksonville, Florida) under the trade designations SENERSHIELD-R, FINESTOP RA, ACROSTOP R, SONOWALL FTR, ENERSHIELD HP, ENERSFJJELD I, SENERSFJJELD VB, and FINESTOP VB. SENERSHIELD-R, FINESTOP RA, ACROSTOP R, SONOWALL FTR, and ENERSHIELD HP are flexible, acrylic liquid coating materials. SENERSHIELD-R, FINESTOP RA, ACROSTOP R, SONOWALL FTR, and ENERSHIELD HP provide a brush-, roller- or spray- applied continuous membrane that is suitable for direct application to a wide variety of approved building wall substrates, such as plywood sheathing, cement board, gypsum sheathing, oriented strand board, poured concrete substrates, masonry unit, and the like.

A lath is used as a plaster base for the stucco coating over the continuous thermal insulation layer or the underlying building wall substrate The lath may be manufactured from metals (such as wire lath, welded-wire lath, and expanded metal lath), metal alloys, polymeric materials, inorganic fiber materials (such as glass fibers), composite materials, and the like. According to certain illustrative embodiments, the lath used in the stucco system and building wall incorporating the stucco system comprises a woven, enhanced thickness inorganic fiber fabric commercially available from BASF Corporation - Wall Systems (Jacksonville, Florida, USA) under the trade designations PERMALATH and PERMALATH 1000. The term stucco is intended to refer to any render material that comprises a blend of a binder material, aggregate and water that is generally used as a wall covering material for building walls. Without limitation, stucco may comprise a blend of lime, sand aggregate, and water, or a blend of Portland cement, sand aggregate, and water, or a blend of Portland cement, lime, sand aggregate, and water. The stucco material may also include reinforcing fibers to improve the properties of the hardened stucco. Stucco materials are often referred to in the building and construction industry as Portland cement-based plaster. The stucco coating may be applied to the insulation layer or building wall substrate in accordance with ASTM C926 (2006) entitled "Standard Specification for Application of Portland Cement-Based Plaster". ASTM C926 describes the requirements for the application of full thickness Portland cement-based plaster materials for exterior and interior building walls. A wide variety of stucco base coats and finish coats are commercially available from BASF Corporation - Wall Systems (Jacksonville, Florida, USA). An illustrative embodiment of the stucco system will now be described in greater detail with reference to the FIGURES. It should be noted that the stucco system is not intended to be limited to the illustrative embodiments shown in the FIGURES.

FIGS. 1 -3 show an illustrative embodiment of the trim bead 10. Trim bead includes front wall 12 having opposite facing surfaces 14, 16. Bottom wall 18 of the trim bead 10 extends outwardly surface 14 of the lower portion of front wall 12. The vertical height between bottom wall 18 and flange 26 is commonly referred to in the construction industry as the ground. Rear wall 20 extends upwardly from bottom wall 18 of trim bead 10. Rear wall 20 extends upwardly from bottom wall 18 to a height that is greater than the height of front wall 12 of the trim bead 10. While not intending to be bound to any particular geometry or shape, the illustrative embodiment of the front, bottom and rear walls create a substantially J-shaped trim bead 10.

Still referring to FIGS. 1-3, bottom wall 18 of the trim bead 10 includes one or more openings 22 that communicate through the entire thickness of bottom wall 18. These openings 22 are commonly referred to in the construction industry as weep holes and are used to drain incidental water from the wall to the external environment. Rear wall 20 may include one or more openings 24 that communicate through the entire thickness of the rear wall 20 to accommodate mechanical fasteners to secure the trim bead to the exterior surfaces of a framed wall or to the exterior surfaces of the building wall substrate layer that is attached to the building wall frame. The rear wall 20 is commonly referred to in the construction industry as the mounting or back flange.

Turning to FIGS. 4 and 5, building wall 30 includes framing members 34, 36. Attached to framing member 36 is a layer of building wall sheathing 38. Trim bead 10 is attached to the exteriorly facing surface of building wall sheathing 38 with mechanical fastener 40. A weather resistive barrier 42 is applied over the exteriorly facing surface of the building wall sheathing 38. The weather barrier 42 overlaps at least a portion of the rear wall 20 of the trim bead 10. A layer of continuous thermal insulation board 50 is engaged with the trim bead 10. The rear surface 52 of the insulation board is positioned substantially adjacent to the weather resistive barrier 42. The lower surface 54 of the insulation layer is supported by the flange 26.

Referring to FIG. 5, a corner bead 60 is often used and engaged with the flange 26 of the trim bead 10. At least one layer of stucco 62 is applied over the lath 64 and continuous thermal insulation layer 50. Because the flange 24 and corner bead 60 provide mechanical keying for the stucco layer 62, the stucco layer is able to surround the thermal insulation layer 50, including the exposed lower edge 54 of the thermal insulation layer 50. In the event of industry standard fire testing (National Fire Protection Association or NFPA 285) where fire emanates from the windows of the building and upwardly along the exterior surface of the building wall 30, the use of the flange 26 and corner bead 60 permits the stucco layer 62 to protect the thermal insulation layer 50, which is typically a rigid expanded polystyrene insulation board.

An illustrative embodiment of the exterior finishing system was tested in accordance with the guidelines set forth in NFPA 285 (National Fire Protection Association). NFPA 285 discloses the standard test method for the evaluation of fire propagation characteristics of exterior non-load-bearing wall assemblies containing combustible components. The illustrative embodiment comprised a trim bead; an exterior building wall comprised of a frame with an exterior surface; a weather resistant barrier attached to the wall; an insulation layer attached to the wall; a lath attached to the insulation layer; and a stucco coating. Fifty-four (54) Type K, fiberglass jacketed thermocouples were installed within the wall system according to NFPA 285. The thermocouple data was monitored every fifteen (15) seconds by a 100-channel Yokogawa, Inc., Darwin Data Acquisition Unit. A commercial grade propane gas burner assembly was positioned on the vertical centerline, nine (9) inches below the top of the window opening, and on the horizontal centerline, three (3) inches from the plane of the exterior wall.

Temperature data from twenty-four (24) of the thermocouples were used to determine compliance with the NFPA 285 standard. Thermocouples 11, and 14-17 were positioned on the exterior wall surface. Thermocouples 18, 19, 28, and 31-40 were positioned within the exterior finishing system core. Thermocouples 49-54 were positioned on the second floor interior wall surface. Compliance with the NFPA standard required that thermocouples 11 , and 14-17 not exceed 1000°F, thermocouples 18, 19, 28, and 31-40 not measure a temperature rise of greater than 750°F, and thermocouples 49-54 not measure a rise over 500°F. The results of the test are provided in Tables 1 -3 below.

Based upon the thermocouple data in Tables 1-3, the illustrative embodiment described above achieved the NFPA 285 standard.

While the trim bead, exterior finish system, stucco system, building wall, and related methods have been described in connection with various embodiments, as shown in the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the same function. Furthermore, the various illustrative embodiments may be combined to produce the desired results. Therefore, the trim bead, exterior finish system, stucco system, building wall, and related processes should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.

Claims

1. An exterior finish system for a building wall comprising:

a trim bead comprising spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall, wherein said flange includes a plurality of openings communicating through the thickness of the flange;

an insulation layer;

and at least one layer of an exterior finishing coating applied to the insulation layer and the flange of the trim bead.

2. The exterior finish system of claim 1, wherein said bottom wall comprises at least one weep hole.

3. The exterior finish system of claim 2, wherein said rear wall comprises at least one opening communicating at least partially through the thickness of the rear wall.

4. The exterior finish system of claim 1 , wherein said flange comprises a mesh.

5. The exterior finish system of claim 4, wherein said mesh comprises a diamond mesh.

6. The exterior finish system of claim 1 , wherein said flange comprises a ribbed structure.

7. The exterior finish system of claim 1, wherein said flange is perforated.

8. The exterior finish system of claim 1, wherein as flange is stamped.

9. The exterior finish system of claim 1, wherein said flange is expanded.

10. The exterior finish system of claim 1 , wherein said trim bead comprises polymer material, a metal material, a metal alloy material, or composite material.

1 1. The exterior finishing system of claim 1 , further comprising a weather resistive barrier.

12. The exterior finishing system of claim 1, further comprising a reinforcement layer attached to said insulation layer for holding exterior finishing coatings.

13. A building wall comprising:

a frame;

a trim bead attached to the frame, said trim bead comprising spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall, wherein said flange includes a plurality of openings communicating through the thickness of the flange;

an insulation layer adjacent the trim bead and attached to said frame; and at least one layer of an exterior finishing coating applied to the insulation layer and the flange of the trim bead.

14. The building wall of claim 13, further comprising a reinforcement layer attached to said insulation layer.

15. The building wall of claim 14, wherein said reinforcement layer comprises a lath.

16. The building wall of claim 15 wherein said exterior finishing coating comprises: at least one layer of a stucco coating applied to the insulation layer, a lath, and the flange of the trim bead.

17. The exterior finishing system of claim 13, further comprising a weather resistive barrier.

18. A building wall comprising:

a frame;

a building wall substrate attached to the frame;

a trim bead attached to the building wall substrate, said trim bead comprising spaced- apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall, wherein said flange includes a plurality of openings communicating through the thickness of the flange;

an insulation layer adjacent the trim bead and attached to said building wall substrate; and at least one layer of an exterior finishing coating applied to the insulation layer and the flange of the trim bead.

19. The building wall of claim 18, further comprising a reinforcement layer attached to said insulation layer.

20. The building wall of claim 19, wherein said reinforcement layer comprises a lath.

21. The building wall of claim 18 wherein said exterior finishing coating comprises at least one layer of a stucco coating applied to the insulation layer and the flange of the trim bead.

22. The exterior finishing system of claim 18, further comprising a weather resistive barrier.

23. A process for finishing an exterior building wall comprising:

attaching a trim bead to the exterior surfaces of a frame, wherein the trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall, and a plurality of opening communicating through the thickness of the flange;

attaching an insulation layer to the building wall substrate; and

applying a layer of an exterior finishing material coating to the surfaces of the insulation layer and the flange of the trim bead.

24. The process of claim 23, further comprising attaching a reinforcing layer to said insulation layer.

25. The process of claim 24, wherein said attaching a reinforcing layer to said insulation layer comprises attaching a lath to said insulation layer.

26. The process of claim 25 comprising:

applying a layer of a stucco coating to the surfaces of the insulation layer, the lath, and the flange of the trim bead.

27. The exterior finishing system of claim 23, further comprising a weather resistive barrier.

28. A process for finishing an exterior building wall comprising:

attaching a building wall substrate to a frame;

attaching a trim bead to the exterior surfaces of the building wall substrate, wherein the trim bead comprises spaced-apart front and rear walls, a bottom wall connecting the front and rear walls, and a flange portion extending from the front wall, and a plurality of opening communicating through the thickness of the flange;

attaching an insulation layer to the building wall substrate; and

29. The process of claim 28, further comprising attaching a reinforcing layer to said insulation layer.

30. The process of claim 29, wherein said attaching a reinforcing layer to said insulation layer comprises attaching a lath to said insulation layer.

31. The process for finishing an exterior building wall of claim 28 comprising:

applying a layer of a stucco coating to the surfaces of the insulation layer and the flange of the trim bead.

32. The exterior finishing system of claim 28, further comprising a weather resistive barrier.