CA2640490A1 - The mary wall - Google Patents

Abstract

The invention relates to a system (and components) for an exterior "prefabricated curtain wall". With built in moisture and ventilation management. The object of the invention is to improve the durability of the wall with a continuous seal installation and integrating ventilation to enable drying behind the finished system. Also these specific components and a combination of these components for possible other applications i.e.
firewall.

Description

15 Description BACKGROUND OF THE INVENTION
1. Field of the Invention The invention relates to a system (and components) for an exterior curtain wall system 20 with built in moisture and ventilation management and a integral steel stud frame. The object of the invention is to create a non-combustible non-mould propagating impact resistant curtain wall with a continuous seal installation integrating a rain shield and pressure equalization to promote drying and reduce water penetration behind the finished system.

25 2. Description of the Related Art.

Walls of buildings not formed of reinforced concrete typically comprise of structural elements made of steel, concrete and like materials and have cladding components attached thereto. The cladding is generally fmished with a decorative finish such as, wood 30 boards, vinyl siding, hung pre-cast decorative concrete slabs with varying textures or an exterior multi-layered system terminating with an outer surface of a polymer/particulate decorative material. In the latter case, the exterior finish is also provided as a rain-fast surface.

35 Certain types of walls of buildings have an inner cavity between the outer cladding and an inner wall, typically consisting of a plasterboard material. The aforesaid cavity permits air movement with the outside atmosphere to provide an air pressure equalization chamber and moisture vent conduit for moisture infiltrating through the outer cladding.
Notwithstanding the high degree of care during construction to provide a moisture-40 impermeable outer surface, over time by the action of wind and rain, temperature fluctuations etc, small cracks invariably are formed in this layer which allows moisture to enter the cavity and into the interior of the building. Thusly the cavity must include a weep or vent hole to drain water from the cavity.

The Mary Wall Page 4 Do not copy One cladding system presently in use which lacks an inner cavity, comprises of a multi-layer system of a typically 6-8 cm thick layer of insulating foam, such as, (EPS) which is adhered to a wall sheathing with adhesives and mechanical fastening devices with large washered heads. Adhered to the outer surface of the foam layer is, typically, a reinforcing layer of two or more glass fiber meshes floated in a polymer-cement modified basecoat which is hand applied by a trowel. This basecoat protects the foam insulation layer from both physical damage and moisture ingress. To this outer basecoat layer is applied an exterior decorative layer of a polymer-particulate material, typically, sand dispersed in an acrylic polymer.

Such multi-layer cladding is formed, generally, from handle able, rectangular (EPS) panels of dimensions of 1.2 m. by 0.6 m. by 4 cm. being adhered to a wall substrate then the other materials being built up upon it.
The cladding comprising an accumulation of such (EPS) panels is formed by them being cooperatively bonded in adjacent relationship as to provide insulation to the wall. Such construction lies well within the skill of plasterboard tradesmen.

In considering the desirability of a particular type of cladding system for use on a wall, regard must be given to the effect of wind pressure and rain on the outer wall surface.
With the absence of airflow between the outside atmosphere and the atmosphere between the cladding and the substrate, significant air pressure differentials may result depending on the velocity of the wind acting on the wall system as well as the geometric design of the building and the resulting wind turbulences.
With large pressure differentials existing between the outside and inside of the building, significant moisture ingress through hair-line cracks and other unintentional openings such as around windows and doors can occur. In the absence of a cavity in the wall, such moisture will reach and damage the inside surface of the wall of the building and with no means to escape, will begin the process of rot, mold and mildew formation.
Accordingly, a cavity within a clad wall system is preferred. Cladding systems which make every attempt to seal water from entering by way of a sealing membrane or other means, suffer the risk of water penetration over time.
Thus, while the aforementioned system may offer a reasonable esthetically pleasing exterior wall fuiish, such a wall often suffers from the effects of water damage hidden beneath its surface A system was required emerging from efforts to apply basic moisture management principals arising from the 1990's "Leaky Condo" situation in British Columbia, Canada with good quality construction principals in an industry losing its skilled labour resources. The industry is currently using well-tested products that have been modified to overcome adverse criticism. An inherent problem discovered in the conventional (EIFS) currently being used is the growth of mould and mildew resulting in rotting and often total failure of the underlying substrate and even the structural building components themselves.

The Mary Wall Page 5 Do not copy When masonry walls were thick and the materials used were quite porous, their very mass absorbed the rainwater and later released it. Eventually, though, walls became thinner and something had to be done to prevent rain penetration. That could be either a face-sealed wall, which in a sense is a rainwater barrier in the form of vinyl or aluminum cladding on the outside wall, or a cavity wall, which consists of one wall just to catch the rain and an adjacent cavity to serve as a moisture break. With open rain screen walls, which reflect current thinking in wall construction, the cladding constitutes the first line of defense. And then there is a second line of defense."1 Current (EIFS) rely on the on-site assembly of a series of laminated layers of unlike building materials attached to the substrate with adhesives, cement based coatings, and fiber mesh reinforcement before the fmished coat of stucco can be applied. The drying time between some layers can take up to 48 hours, weather permitting.
Furthermore, any infiltration of water or moisture during the installation period can be trapped, beginning its destructive course even before the new job is completed. In this regard, even a careful professional installation cannot guarantee short term subsequent moisture protection to the structure.
SUMMARY OF THE INVENTION
This invention relates to the design and installation of a Prefabricated curtain wall system using a existing cladding system which has been modified to allow the steel stud to be inserted into the substrate with a rain shield and pressure equalization channel added The Mary Wall comprises an assembly of engineered Cementitious coated (EPS) Stucco Base Panels mechanically fastened with screws or similar devices to a engineered steel stud frame.
The invention is an innovative departure from conventional construction methods. The System is not only in the product, but also in the process itself. Using an exterior cementicious Stucco Base Panel for use in the residential and commercial construction industry.

The Stucco Base Panels are installed in one step directly onto the wall frame The joints are filled with a quick-drying polymerized mortar and the surface is immediately ready for a durable fniish coating.
Typically, the specific use is in the exterior wall of a building which is characteristically finished with a synthetic stucco material, commonly known to the (EIFS) trade It is the intent of the present invention to provide an improved wall system for the wall of a building which can be readily constructed in factory or on-site and which provides air pressure equalization.

It is a further intended to provide a plurality of interconnecting air pressure and moisture vent channels which not only equalize pressure, but also permit the drainage of infiltrated moisture.

' Chown, G.A., W.C. Brown and G.F. Poirier Evolution of Wall Design for Controlling Rain Penetration Construction Technology Updates, No. 9.

Ottawa: National Research Council of Canada, Institute for Research in Construction 1997 The Mary Wall Page 6 Do not copy Further it is to provide a curtain wall manufactured in a controlled environment resulting in a level of superior and consistent quality that incomparably surpasses that of any on-site assembly which is required by conventional (EIFS).
T'he moisture management principals of the cladding system meet the requirements of the (OAA) Ontario Associates of Architects Rain Penetration Control Practice Guide for exterior wall design without the addition of a secondary drainage mat.
The system is a continuous-sealed system that does not rely on the face-sealed system of the currently used in (EIFS), but rather on the secondary line of defense of engineered drainage channels and ventilation cavities built into the system that dissipate any moisture infiltration once installed.
Installation of the Mary Wall does not require skilled specialty workers. The speed and ease of the installation substantially reduces the construction timeline, which translates into a more efficient building project, which further translates into cost-savings for the builder.
The integrity of the Mary Wall is not only in the discernible attributes of the design, but also with the durability of the product. The Mary Wall is ideally engineered from both sides. The polymerized Cementitious surface is exceptionally well suited for finish coatings and the underside is designed with unique moisture management principals integrated into its inherent structure providing moisture drainage by the action of gravity and evaporation of moisture through air circulation between the panels.
Conventional flashing practices, seals, and caulking are applied at the unions with other building components and the Panel.

The invention provides in a further broad aspect, an improved cladding of the wall of a building, said cladding system comprising a plurality of Stucco Base Panels in an adjacent relationship as to provide a continuous sealed installation and said Stucco Base Panels being so shaped as to provide said cladding system with a plurality of interconnecting air pressure equalization and vent channels.

By " adjacent relationship" it is meant that the cladding Stucco Base Panels are installed one adjacent to another inserted over a steel frame The term "curtain wall with a plurality of interconnecting air pressure equalization and moisture vent channels", is meant a wall having a system of parallel vertically aligned channels which intersect solely with a single, horizontally aligned channel extending across the width of the wall at each join, particularly, at a lower part thereof.

The Stucco Base Panels are shaped such that when they are part of the wall they produce, in consequence of adjacent relationship with other Stucco Base Panels, a plurality of channels which inter-connect with each other and via a lower flashing member and an upper protected flashing member with the outside atmosphere. The plurality of channels may extend substantially across the full area-of the cladding. The wall may be provided with intervening structures such as doors or windows which may abut, directly or indirectly, the Stucco Base Panels according to the invention, but which still satisfies the object of the invention. With the staggered vertical edge joints of the Stucco Base Panels The Mary Wall Page 7 Do not copy resulting in the non-alignment of the vertical drainage channels the Stucco Base Panels are so shaped as to remedy the consequential blockage of water and air Flow between courses.

The modified design of the Stucco Base Panel provides a portion defining a channel edge running along the full length of the base of the Stucco Base Panel which interconnects with the vertical beveled channels to provide interconnecting air pressure equalization, vent and drainage channels.

Each of the wall Stucco Base Panels may be of any suitable shape and dimension.
Preferably, the Stucco Base Panel is roughly a 1.2 m×0.4 m×5.0 cm rectangular shaped member.

The Stucco Base Panels may be so shaped as to provide suitable joint configuration and dimension to permit satisfactory surface area for mortar joint material. In one embodiment, the Stucco Base Panel coating has radiuses edge portions along 2 edges.
The radiuses portion may be defmed by the edge surface as a quadrant actuates form, semi-square form or 45 degree angled form. Preferably, the radius extends the whole length of each of the 1.2 m long sides.
The wall assembly system has preferably an airtight inner barrier either adhered to the stud or disposed between the substrate and the cladding Stucco Base Panels.

One very important consideration that must be given to the construction of a wall system, particularly, cladding of commercial and industrial buildings, is that concerning fire prevention and retardation.

Prior to the commercial introduction to the trade of a novel wall for use in a commercial or industrial building, the wall materials and constructed wall must undergo extensive, standard fire testing. In one such test, a flame is played onto the back of the (EPS) isolative cladding to determine whether the resultant system meets the regulatory requirements.

It is known that (EPS) melts at 170 degrees Celsius to a viscous, but mobile fluid, thus, in the wall cladding structure according to the invention, it is reasonable to expect that, notwithstanding the fire retardancy of the conventional (EPS), under certain high temperature conditions the (EPS) may melt and exit to and through the lower flashing according to the invention. Further, it is realized that the cladding material itself can detach from the building and fall onto neighboring structures or people in the event of a fire.

Accordingly, to reduce the possibility of the cladding detaching in this manner the invention provides in a fnrther aspect, wall cladding of a building as hereinabove defined wherein the coating itself is mechanically fastened to the steel stud with the fastening device securely embedded in typically 1.2 to 2.5 cm of the typically 1 cm thick The Mary Wall Page 8 Do not copy Cementitious material. This provides a stable non-moving cladding surface which would stand off the substrate in the event of liquefaction of the (EPS) portion.

In addition to the above consideration the formulation of the cladding coating is non-combustible for such installations and thus acts as an enhanced flame-spread protection and provides improved fire safety.

In its simplest form, this aspect of the invention comprises a non-combustible Cementitious cladding coating mechanically fastened to a integral steel stud fiame with an (EPS) spacing material beneath with sufficient channels to properly achieve water drainage and air pressure equalization.

DESCRIPTION OF THE DRAWINGS

Thus, in order that the invention may be better understood, preferred embodiments will now be described, by way of example only, with reference to the accompanying drawings wherein:
Figure A) shows a front side and back view of the modified Stucco Base Panel Figure B) shows and end view of the cladding Stucco Base Panel Figure C) shows the side view detail view of a modified Stucco Base Panel Figure D) shows a Pressure and drainage cut out of the modified Stucco Base Panel Figure E) shows a close-up detail view of section of installed modified cladding system on stud Figure F) shows a exploded view of the curtain wall assembly Figure G) shows a detail of the panel connections As shown in Figure A, the Modified wall cladding panel shows the preferred embodiments of the Stucco Base Panel comprising of: a pre- shaped (EPS) base having channels cut preferably, but not limited to, full length into the upper surface which serve as reinforcing ribs when the cementicious coating is applied during the manufacturing process. These channels are typically, but not limited to, the dimensions of 0.635 cm wide by 0.635 cm deep.

Two additional channels) are cut into the same surface of the (EPS) cut preferably, but not limited to, full length into the upper surface which serves as mechanical fastening ribs typically, but not limited to, the dimensions of 1.9 cm wide by 0.95 cm deep. It is into the width center of these ribs that a fastening device is used.
The said fastening device is located along points the length of the Stucco Base Panel such that it penetrates through the (EPS) back surface feature resulting in a seal being formed between the steel stud and the (EPS) The base or lower surface of the (EPS) material has a channel cut along and across the Stucco Base Panel's width. These channels are cut along the width of the (EPS) creating voids (evaporation cavities) allowing for air and water movement when the Stucco Base The 1V1ary Wall Page 9 Do not copy Panels are installed. These channels can be of differing shapes with the sides of the channels being at 90 (degrees) to the base of the channel or other angles. The preferred, although not limited to, shapes are beveled channels running the width of the panel. The beveled shape of the channels draws flowing or dripping water from the substrate towards outside of the (EPS) material core.

Intersecting the channels are channels cut across the width of the base (EPS) surface of the Stucco Base Panel. Ideally, although not limited to being cut with square sides as opposed to beveled sides. These serve as drainage channels to flowing water as well as ventilation channels for air circulation by convection in the finished wall system. When the Stucco Base Panels are installed vertically, the bevel on each base of the (EPS) , allow the flow of water along the edges of the Stucco Base Panel to the next closest drainage channel.
The top surface of the Stucco Base Panel is a cementicious layer which is typically, but not limited to 0.95 cm thick which extends across the width of the (EPS) leaving typically but not limited to l.mm to 2. mm (EPS) extending beyond the coating. This serves the function of installing the Stucco Base Panels atop one another with the (EPS) edge of one Stucco Base Panel fully contacting the (EPS) edge of the adjoining Stucco Base Panel.
The compressive quality of the (EPS) prevents cracking of the cladding system joints during freeze thaw cycles of expansion and contraction of the system components. The edge of this coating is shaped in a radius to provide a larger surface area onto which the mortar can adhere to. This radius can be of varying shapes to serve the same purpose such as but not limited to, straight beveled, wavy, notched and concave.
Stucco Base Panels are installed vertically onto a wall stud frame as shown in Figure E &
F) comprising of wall studs and a Interior vapor barrier such as 6mm poly .
The drainage channels run vertically and the evaporation cavity channels (2) run horizontally.
The vertical Stucco Base Panel joints are flush with a 2mm gap between the Stucco Base Panel end joints allowing for mortar penetration. The first course of Stucco Base Panel is installed on a starting strip of perforated plastic or rust-proof metal flashing as shown in Figure 6. This flashing strip protects the lower edge of the (EPS) from damage and deterioration but allows for air and water transmission through the perforations. The perforations in the flashing are small enough to prevent insects from entering, and are numerous enough to allow for drainage and ventilation.
All joints between the Stucco Base Panel and countersunk screw heads are filled with a polymerized mortar or other suitable bonding material known to the art of adhesion. After installation the surface of the Stucco Base Panel and joint mortar (the cladding surface) is coated with a finish coating, preferably but not limited to Synthetic Flexible Stucco to render a uniform desired fmished surface.
When installing the cladding system at an inner corner), The Stucco Base Panel of one wall surface are installed with their ends directed towards the adja.cent wall surface, leaving a gap of 0.6 cm to 1 cm to allow for movement of the building structure independent of the cementicious coating to prevent cracking of the cladding system at the corner due to settling of the building structure. The Stucco Base Panels applied to the adjacent wall are fastened with their end surfaces touching the previously installed Stucco Base Panels. A flexible caulking compound previously known to the art is applied to the joint between the cladding wall surfaces where they form the inside corner.
This The Mary Wall Page 10 Do not copy installation procedure will provide the cladding system with a "live joint" at the inside corner allowing for movement without compromising the integrity of the system as a whole.
When installing exterior corners, standard building practice is used and a stucco based panel is inserted as filler as required under a prefabricated corner molding available in any building product supplier known to the art. This configuration provides an outer corner edge of cementicious material, which when finished with a mortar coating and results in a solid exterior corner structure suitable for application of a finish material thereon.
The orientation of the resulting corner joint is alternated with each course of Stucco Base Panels filler panels being installed Fastening screws are used back from the outer corner edge of the Stucco Base Panels so that they penetrate the substrate and not the overlapped Stucco Base fuiish corner. Care must be taken at this point to ensure the fastening device is in fact penetrating the stud.
At all other termination points on the building where the cladding system adjoins non-cladding elements such as windows, doors, roofs, etc., flashing, caulking and other moisture protection devices are used in accordance with standard building construction practices known to the art.

Claims (21)

1. A lightweight steel assembly and modified cladding system for The Mary Wall, said cladding assembly comprising of:
18 gauge steel stud and track and a modified (EPS) expanded polystyrene base onto which has been applied a coating of a Cementitious mixture of varying thickness resulting in a Stucco Base Panel with a smooth even top surface extending 1/16" from the edges of the base along the sides and with a radius creating a rounded coating edge, and flush with the ends of the base of the Stucco Base Panel.
The base of the panel is shaped with a channel which creates a space between the bottom of the stacked Stucco Base Panel and the top of the connecting stucco base Panel.

2. The steel assembly combined with the modified stucco Base Panel creates a curtain wall which is non-combustible in its formulation.

3. The curtain wall of Claim 2 can be manufactured by installing steel stud into the EPS substrate that has the non-combustible patented coating formulation from Icon

4. The curtain wall of Claim 1 wherein said Stucco Base Panels communicate with each other to form a continuous surface with visible edge unions.

5. The Mary Wall of Claim 6 which can be mechanically fastened to a building frame.

6. The stucco base panel of Claim 7 which has the joints filled with a mortar material

7. The stucco base panel of Claim 8 which allows for countersinking of the mechanical fastening devices rendering them invisible and which does not compromise the integrity of the fastening strength.

8. The Mary Wall of Claim 9 which can be installed with vertical orientation to maintain its drainage characteristics.

9. The Mary Wall of Claim 10 which forms a complete uninterrupted continuous seal wall system.

10. The Mary Wall of Claim 11 which possesses higher impact resistance as compared with other comparable synthetic stucco wall cladding systems.

11. The Mary Wall of Claim 11 which does not require fiber or mesh reinforcement in its structure.

12. The stucco base panel of Claim 1 wherein channels are present which intersect with each other at 90 degrees.

13. The stucco base panel of Claim 1 wherein the channels permit moisture and air flow.

14. The stucco base panel of Claim 1 wherein base edge channels create a path for drainage from one Stucco Base Panel to another regardless of one Stucco Base Panel's alignment to another.

15. The Mary Mall of Claim 1 wherein indicator marks on the surface guide the location for fastening devices to be used for installation.

The Mary Wall Page 3

16. The stucco base panel of Claim 1 wherein a seal is created between the (EPS) base and the substrate where the fastening device is used.

17. The stucco base panel of Claim 1 wherein structural surface ribs are incorporated for impact resistance.

18. The Mary Wall of Claim 1 wherein water drains from the lower edge of the lower panel through a flashing strip and rain shield channels on the stucco base panel.

19. The Mary Wall of Claim 1 wherein the air movement within the system can terminate at determined locations within the system.

20. The Mary Wall of Claim 1 wherein air circulation can be forced by external means.

21. The Mary Wall of Claim 1 wherein air circulation can be by means of convection.