Pre-cast rain screen wall panel

A prefabricated rain screen wall panel is provided comprising inner and outer concrete panels secured together by shear connectors. Intermediate members provide insulation, a drainage channel and a vapor barrier.

FIELD

The invention relates to the control of moisture within walls using a pre-cast construction. In a particularly preferred embodiment, the invention relates to a modular pre-fabricated wall panel, which may be used in the construction of a building wherein the building has an outer facing of stucco, brick, wood or aluminum siding or the like.

INTRODUCTION

Structural walls for buildings, such as residential, commercial or industrial buildings, are often constructed in layers. Typically, a wall sits on a foundation and includes a back-up wall having a floor plate and a ceiling plate and a set of vertical studs. Usually sheathing, which may be plywood, oriented strand board or the like, is disposed on the outside face of the back-up wall (i.e., the side that faces towards the outside of the building). The sheathing is covered by a moisture barrier membrane. Insulation is typically installed on the outside face of the moisture barrier membrane. An outer facing, such as stucco, brick or a siding material is then typically provided as the outer component of the wall.

Pre-fabricated wall sections are known. For example, Carlson (U.S. Pat. No. 3,828,502) discloses a pre-fabricated panel wherein insulation is surrounded by a thin skin, which may be aluminum. Huettemann (U.S. Pat. No. 4,841,702) discloses a three-layer insulated concrete panel. The middle layer comprises an insulating slab having grooves, which provide a form for casting of concrete supporting ribs integral with a layer of concrete cast over the grooved face. Rebar may also be positioned in the grooves.

SUMMARY

In accordance with this invention, a pre-fabricated rain screen wall panel is provided. The pre-fabricated wall panel comprises a multi-layer panel, which includes channels to permit water to flow internally in the wall panel downwardly and be evacuated from the pre-fabricated construct by any means known in the art. Accordingly, the pre-cast wall panels may be installed on any standard foundation and installed such that any water that accumulates at the bottom of the wall panel may drain to the outside of the building.

An advantage of the design is that it permits wall panels to be constructed, such as in a factory and then conveyed to a building site where the panels may be assembled together on a foundation to produce a wall of a building. It will be appreciated that wall panels may be constructed in a variety of sizes so as to accommodate any particular profile of the outer perimeter of a building.

The pre-fabricated construction permits the wall panels to be assembled under more appropriate conditions than occur at a building site. For example, the concrete may cure under more ideal conditions thereby increasing the strength of the concrete. In addition, as opposed to pouring concrete into a vertical mould, the concrete may be pre-fabricated in horizontal layers thereby assisting in ensuring the absence of voids or the reduction of voids in the concrete, which may impair the strength of the concrete.

In accordance with a first aspect of this invention, there is provided a prefabricated assembly comprising:(a) inner and outer concrete panels;(b) an intermediate drainage panel positioned adjacent the outer concrete panel and having an inner face and an outer face and a plurality of drainage channels provided on a face thereof, the outer face is adjacent an inner face of the outer panel;(c) an intermediate insulation panel positioned adjacent the intermediate drainage panel;(d) a vapour barrier positioned between the intermediate insulation panel and the inner concrete panel; and,(e) a plurality of shear connectors, each having a first portion, a second portion and an intermediate portion extending between the first and second portions, the first portion provided in the inner concrete panel and the second portion provided in the second concrete panel.

In some embodiments, the drainage channels are provided on the inner face of the intermediate drainage panel.

In some embodiments, the inner face of the intermediate drainage panel is adjacent an outer face of the intermediate insulation panel.

In some embodiments, the vapour barrier is positioned between an inner face of the intermediate insulation panel and an outer face of the inner concrete panel.

In some embodiments, the first and second portions are configured to be secured in the concrete panels.

In some embodiments, the intermediate portion extends at an angle to each of the first and second portions.

In some embodiments, the intermediate drainage panel comprises insulation material.

In some embodiments, the prefabricated assembly further comprises rebar provided in each of the inner and outer concrete panels and the first portions are secured to rebar in the inner concrete panel and the second portions are secured to rebar in the outer concrete panel.

In some embodiments, the intermediate drainage panel has an absence of internal channels.

In accordance with another aspect of this invention, there is also provided a prefabricated assembly comprising:(a) inner and outer concrete panels;(b) first and second intermediate panels positioned between the inner and outer concrete panels, one of the first and second intermediate panels having a plurality of drainage channels provided on a face thereof, each of the intermediate panels having an inner face and an outer face;(c) a vapour barrier positioned between the inner and outer concrete panels; and,(d) a plurality of shear connectors, each having a first portion, a second portion and an intermediate portion extending between the first and second portions, the first portion provided in the inner concrete panel and the second portion provided in the second concrete panel.

In some embodiments, the drainage channels are provided on the inner face of the first intermediate panel.

In some embodiments, the inner face of the first intermediate panel is adjacent an outer face of the second intermediate panel.

In some embodiments, the vapour barrier is positioned between an inner face of the second intermediate panel and an outer face of the inner concrete panel.

In some embodiments, the first and second portions are configured to be secured in the concrete panels.

In some embodiments, the intermediate portion extends at an angle to each of the first and second portions.

In some embodiments, the prefabricated assembly further comprises rebar provided in each of the inner and outer concrete panels and the first portions are secured to rebar in the inner concrete panel and the second portions are secured to rebar in the outer concrete panel.

In some embodiments, the intermediate drainage panel has an absence of internal channels.

In accordance with another aspect of this invention, there is also provided a method of preparing a prefabricated panel comprising:(a) providing a first concrete panel having first portions of shear connectors provided therein, the shear connectors having intermediate portions extending outwardly from the concrete panel;(b) providing a vapour barrier in overlying relation to the first concrete panel, the intermediate portions extending through the vapour barrier;(c) providing an insulation panel in overlying relation to the vapour barrier, the intermediate portions extending through the insulation panel;(d) providing a drainage panel in overlying relation to the insulation panel, the intermediate portions extending through extending through the drainage panel; and,(e) providing a second concrete panel in overlying relation to the drainage panel, the intermediate portions extending to the outer panel, wherein second portions of shear connectors are provided in the second concrete panel.wherein steps (a)-(e) and conducted sequentially in the order of step (a) to step (e) or step (e) to step (a).

In some embodiments, step (a) further comprises providing rebar in the first concrete panel and step (e) further comprises providing rebar in the second concrete panel.

In some embodiments, step (a) further comprises securing the first portions to the rebar in the first concrete panel and step (e) further comprises securing the second portions to the rebar in the rebar in the second concrete panel.

In some embodiments, the method further comprises shipping the prefabricated panel to a construction site.

It has surprisingly been determined that a pre-fabricated panel utilizing sheer connectors to secure together the elements of a panel wherein the panel has internal voids permits a wall panel to be pre-fabricated at one location and then transported and installed without damaging the vapour barrier or the rain channel system incorporated into the pre-fabricated panel.

DESCRIPTION OF VARIOUS EMBODIMENTS

As exemplified inFIG. 1, in accordance with a preferred embodiment of this invention, pre-cast rain screen wall panel10comprises a first or outer concrete panel12and a second or inner concrete panel18wherein a vapour barrier24, an intermediate insulation panel30and an intermediate drainage panel36are provided between the inner and outer concrete panels12,18. A plurality of shear connectors44extend between the inner and outer concrete panels12,18and secure the pre-cast rain screen wall panel together as an integral unit.

Outer concrete panel12has an outer surface14and an inner surface16(seeFIGS. 2 and 6). Outer surface14comprises the outer surface of the rain screen wall panel10and accordingly faces outwardly from the building. Accordingly, a facing or other construct, if desired, may be provided on outer surface14, or spaced from and facing outer surface14. It will be appreciated that, in an alternate embodiment, the facing may be integrally formed with panel10.

Outer concrete panel12preferably has a thickness in the direction extending between outer and inner surfaces14,16of between 2-6 inches and preferably 3-4 inches and more preferably about 3 inches. Outer concrete panel12may be constructed from any concrete typically used in building construction. It will be appreciated that outer concrete panel may be of any dimensions and may be customized for any building. For example, outer concrete panel12may have a length of 20 feet or more and a width of 20 feet or more. Alternately, outer concrete panel12may have a length of eight feet and a width of four feet. It will be appreciated that, if larger dimensions are utilized, that the thickness of outer concrete panel12is preferably increased.

Positioned inwardly from outer concrete panel12is intermediate drainage panel36. Intermediate drainage panel36has outer surface38and inner surface40(seeFIGS. 2 and 7). Outer surface38is preferably positioned immediately adjacent and touching inner surface16of outer concrete panel12. Inner surface40of drainage panel36is provided with at least one and preferably a plurality of drainage channels42(seeFIGS. 2 and 3). The drainage channels42are configured such that water positioned between intermediate drainage panel36and intermediate insulation panel30may drain to the bottom of panel10. Accordingly, drainage channels42preferably run from the top of panel10to the bottom of panel10, preferably in a straight line. Accordingly, as exemplified inFIGS. 2 and 3, drainage channels preferably extend vertically when panel10is installed in a building.

Intermediate drainage panel36preferably has the same dimensions as outer panel12. However, intermediate drainage panel36may be smaller than outer panel12and a plurality may be utilized in the construction of a single panel10.

Intermediate drainage panel36may be constructed from a variety of materials and, preferably, is constructed from an insulating material. Preferably, intermediate insulation panel36is a rigid member. Accordingly, panel36may be constructed from an insulating foam such as rigid, extruded polystyrene. However, other insulating materials may be used or other rigid materials capable of having drainage channels therein may be used. Intermediate drainage panel36may provide insulation value and may contribute to the overall R-value of the panel10. Accordingly, the material that is used and/or the thickness of intermediate drainage panel36may be selected to achieve a particular R-value for intermediate drainage panel36. For example, intermediate drainage panel36may be from 1 to 4 inches thick and preferably is about 1-1.5 inches thick and more preferably is about 1 inch thick.

Drainage channels42may be integrally constructed with panel36(e.g., molded into a surface of panel36). Alternately, drainage channels may be cut into panel36after it is formed. In a further alternate embodiment, drainage channels42may be an additional layer that is secured to panel36after it is formed. In a particular preferred embodiment, drainage panel36may be a Korax™ panel.

As exemplified inFIG. 3, drainage channels42are spaced apart and recessed inwardly with respect to projecting columns54. Accordingly, each drainage channel42may comprise a generally U-shaped channel, which is recessed inwardly from the outer surface56of projecting columns54. Outer surface56of projecting columns54may be a continuous outer surface. Alternately, a plurality of grooves58extending transverse to projecting column54may be provided. Accordingly, grooves58may provide air or water flow channels from one drainage channel42to the next spaced apart drainage channel42.

Similar to intermediate drainage panel36, intermediate insulation panel30may be the same dimension as outer panel12. Alternately, intermediate insulation panel30may be smaller and a plurality may be used to construct a single panel10.

Intermediate insulation panel30may be constructed from any insulating material. Preferably, intermediate insulation panel30is a rigid member. Accordingly, panel30may be constructed from an insulating foam such as rigid, extruded polystyrene. However, other insulating materials may be used. The material that is used and/or the thickness of intermediate insulation panel30may be selected to achieve a particular R-value for intermediate insulation panel30. For example, intermediate insulation panel30may be from 1 to 5 inches thick and is preferably about 2 inches thick.

It will be appreciated that, combined, intermediate drainage panel36and intermediate insulation panel30may provide the requisite insulation for panel10. Accordingly, the thickness and/or the material used to construct either may be varied provided that the requisite overall R-value for panel10, if needed, is obtained. Additional intermediate layers may be provided and their sequence varied. Further, if intermediate drainage panel36provides sufficient insulation value, then intermediate panel30need not provide any insulation value and may be made of any material. In such a case, intermediate panel30provides a surface to ensure that the drainage channels remain open once the panel10is constructed.

Vapour barrier24is positioned inward of intermediate insulation panel30(seeFIGS. 2 and 9). Vapour barrier24has an outer surface26and an inner surface28. Vapour barrier26may be made from any moisture control membrane known or used in the building arts. It may be a thermally fused membrane, a peel and stick air vapour barrier or any other approved air vapour barrier. Preferably, vapour barrier24is the same size as panel12. However, it will be appreciate that a plurality of pieces of vapour barrier24may be utilized and connected together so as to form a vapour barrier that has an extent so as to cover all of outer surface20of inner concrete panel18. It will further be appreciated that a plurality of layers of vapour barrier24may be provided. Outer surface26of vapour barrier24preferably abuts inner surface34of intermediate insulation panel30.

Inner concrete panel18is positioned inward of vapour barrier24(seeFIGS. 2 and 10). Inner concrete panel18has an outer surface20and an inner surface22. Outer surface20preferably abuts inner surface28of vapour barrier24. Inner surface22may be the inner surface of panel10to which a decorative interior coating may be applied. Alternately, inner surface22may be painted or otherwise treated as is known in the art.

Inner panel18may be made from the same type of concrete as outer concrete panel12. Alternately, a different type of concrete may be utilized. Inner concrete panel18may have the same thickness as outer concrete panel12or, alternately, it may have a different thickness. Preferably, in and outer concrete panels12and18have the same thickness.

Panel10is secured together by a plurality of shear connectors44. Shear connectors may be of any configuration that extends between concrete panels12,18and secure them together. As exemplified inFIG. 10, shear connector is provided with a first portion46in outer concrete panel12, a second portion50in inner concrete panel18and an intermediate portion48extending between the first and second portions. In the exemplified embodiment, shear connector44is Z shaped. Accordingly, first and second portions46,50extend at an angle, preferably a right angle, to intermediate portion48. In this configuration, shear connectors44are secured in the concrete of panels12,18so as to resist being pulled outwardly therefrom. It will be appreciated that alternate configurations of shear connectors44may be used. For example, shear connectors44may have first and second portions46,50that extend parallel or generally parallel to intermediate portion48but which have at least one and preferably a plurality of openings therethrough. Accordingly, the concrete of panels12,18, when poured, may flow through the openings and thereby secure shear connectors44in panels12,18. Other designs may also be used.

Shear connectors44may also be in any particular orientation. As exemplified inFIGS. 2 and 5, shear connectors44have a first portion46and a second portion50that are embedded in the concrete layers12,18. As exemplified, these portions preferably extend in the same direction and preferably in a direction perpendicular to the longitudinal axis of the panel10. Referring toFIG. 4, first portion46and second portion50extend away from intermediate portion48in a direction perpendicular to sides62of the form60.

Shear connectors44may also be positioned at various locations in panel10. As exemplified inFIGS. 2 and 5, shear connectors44are preferably evenly spaced apart in rows in panel10. Referring toFIG. 4, rebar52ahas three shear connectors44positioned in a row, namely44a′,44a″and44a′″. Similarly, rebar52bhas three shear connectors44positioned in a row, namely44b′,44b″and44b′″. The middle shear connector44a″on rebar52ais preferably positioned at the centre of panel10. To either side of middle shear connector44a″are outer shear connectors44a′and44a′″that are positioned between the middle shear connector44a″and the sides of panel10(i.e., the sides of the panel at sides62of form60). As there are 3 shear connectors44dividing rebar52ainto four sections, each of these outer shear connectors is preferably positioned inwards about ¼ of the distance of the width of the panel10(i.e. ¼ of the length of side64of form60). Accordingly, the distance between the side of panel10adjacent side62of form60and the proximate outer shear connector44a′is preferably the same as the distance between that outer shear connector44a′and the middle shear connector44a″. Similarly, the distance between the middle shear connector44a″and the other outer shear connector44a″is preferably the same as the distance between that outer shear connector44a″and other side of the panel62. Alternately, or in addition, shear connectors44are preferably evenly spaced apart in columns in panel10. Accordingly, for example, each row of shear connectors44may be spaced from an adjacent row of shear connectors44by a uniform amount. Referring toFIG. 4, one column of shear connectors includes shear connectors44a′,44b′and44c′. That row, as exemplified, comprises 7 shear connectors dividing the rebar into eight sections, each of which is preferably spaced apart the same distance W. Thus, the row of shear connectors44amay be spaced apart from the row of shear connectors44bby a distance W that is the same as the distance between the row of shear connectors44band the row of shear connectors44c. Further, the row of shear connectors44cmay be spaced from wall64of form60be the same distance W. Accordingly, each shear connector will have about the same load placed thereon.

Reference will now be made toFIGS. 4-10which exemplify a method of construction, which may be utilized to prepare panel10.

Referring toFIG. 4, a form60is provided. Form60is preferably sized so as to permit the production of a single panel10. However, it will be appreciated that form60may be sized to permit the production of a plurality of panels10at the same time. The form may be of any construction known in the art, which is suitable to have concrete poured therein and removed therefrom when secured. Preferably form60is made from wood. For example, referring toFIG. 4, form60may comprise first and second opposed wood panels62, which have a length corresponding to the desired vertical height of panel10as shown inFIG. 1and first and second opposed second panels64, which correspond to the width of panel10as shown inFIG. 1. The sides62,64may be nailed together or otherwise secured together as is known in the art.

Preferably, shear connectors44are secured in position prior to concrete being poured into form60. Accordingly, for example, rebar52may be provided in the bottom of form60. Rebar52may extend to sides62,64such that rebar52is visible when panel10is removed from form60(seeFIG. 1for example). Alternately, rebar52may terminate inwards of sides62,64such that the outer edges of outer panel12are continuous and rebar52is not visible when panel10is removed from form60. Preferably rebar52is positioned above bottom66of form60(see for exampleFIG. 5). Accordingly, when concrete is poured into form60to produce outer concrete panel12, concrete will be located above and below rebar52as shown inFIG. 6. Accordingly, outer surface14of outer panel12will be continuous (i.e. rebar52is not visible). Rebar52is positioned such that first portion46of sheet connector44is located in the concrete. Sheer connectors44may be secured to rebar52by any means known in the art. For example, shear connectors44may be secured to rebar52by welding, mechanical fasteners such as tie or other means68known in the building arts.

Once rebar52and shear connectors44are positioned in the bottom of form60, concrete may then be poured into form60so as to produce outer layer12. The concrete may be tamped or otherwise compacted to reduce and preferably prevent the formation of voids or pockets in the concrete and to ensure that the concrete completely fills the bottom of form60.

It will be appreciated that, in an alternate embodiment, rebar52may not be utilized. For example, the concrete may first be poured into form60and the shear connectors44, and preferably the shear connectors tied to rebar52, then positioned in the concrete. Alternately, shear connectors44could otherwise be secured in position in form60, such as being secured to form60itself. It will be appreciated that shear connectors44and rebar52may each be utilized but that shear connectors44need not be secured to rebar52.

Subsequently, preferably after the concrete of outer panel12has at least partially cured (e.g. has a rigid outer surface), intermediate drainage panel36may then be positioned on top of inner surface16of outer panel12(see for exampleFIG. 7).

In accordance with a preferred embodiment of this invention, the shear connectors44are preferably arranged so as to allow panels30and36to be inserted between a series of spaced apart shear connectors44and a section of a wall form or between two series of spaced apart shear connectors. Accordingly, for example, panels36and30may have a width that is equivalent to the distance between spaced apart shear connectors44a′and44a″. Thus, one panel may be positioned between the columns of shear connectors defined by shear connectors44a′and44a″and a second panel may be positioned between the columns of shear connectors defined by shear connectors44a″and44a′″. Accordingly, the intermediate portion48of shear connectors44may be positioned at the adjoining facing edges of adjacent panels30and at the adjoining facing edges of adjacent panels36.

In accordance with such a preferred embodiment, intermediate drainage panel36is sized so as to have width corresponding to the distance between adjacent columns of re-bar. Accordingly, in the embodiment ofFIG. 4, four intermediate drainage panels36may be positioned side by side along the width64of form60. For example, a first intermediate drainage panel36maybe positioned between rebar52cto which shear connector44a′is attached and rebar52dto which shear connector44a″is attached. Accordingly, a first end of intermediate drainage panel36that is parallel to side62of form60may be slid under second portion50of the shear connectors44attached to rebar52dand then lowered to be adjacent inner surface16of panel12. The opposed side of intermediate drainage panel36adjacent rebar52bmay then be lowered by rotating it downwardly so as to seat flush on inner surface16of panel12. Similarly, the first end of another intermediate drainage panel36may then be slid under second portion50of the shear connectors44attached to rebar52cand then lowered to be adjacent inner surface16of panel12. The opposed side of intermediate drainage panel36adjacent side62may then be lowered by rotating it downwardly so as to seat flush on inner surface16of panel12. The remaining sections of form60may then be similarly provided with sections of intermediate drainage panel36. In this way, shear connectors44need not extend through each intermediate drainage panel36. Instead, sections of intermediate drainage panel36may be installed on outer surface16of panel12such that the joint between adjacent intermediate drainage panels36is positioned such that intermediate portion48of shear connectors44extends therethrough. The joint between adjacent panels36may then be sealed, such as by tape, an adhesive, caulking or the like.

It will be appreciated that, in an alternate embodiment, panel36may have an extent (e.g., a length extending in the direction of side62) such that a hole or holes must be provided therein for sliding downwardly over shear connectors44. For example, if an intermediate drainage panel36is of the same size as form60, openings could be provided in intermediate drainage panel36for allowing the panel to be placed vertically downwardly on top of panel12with shear connectors44passing therethrough. Subsequently, the openings, which are provided for shear connectors44, may be sealed, such as by an insulating filler material such as foam.

In accordance with an embodiment of this invention, it will be appreciated that the drainage channels are provided on the upper surface of drainage panel36when panel36is positioned in form60.

Subsequently, as exemplified inFIG. 8, one or more insulation panels30may be positioned on top of drainage panels36. Insulation panel30may be positioned in form60in any manner discussed with respect to intermediate drainage panel36.

Subsequently, as exemplified inFIG. 9, vapour barrier24may be provided on top of insulation panel30. Vapour barrier24may have an extent similar to the extent of form60. Accordingly, a plurality of openings may be provided in vapour barrier24to allow vapour barrier24to be installed on top of insulation panel30. The openings in the vapour barrier through which shear connectors24pass may then be sealed by any means known in the building arts to join together the edges of vapour barrier membranes, such as tape, caulking, placing portions of the barrier material over the joints and securing them in position by tape or an adhesive, or the like. Alternately, a plurality of strips of vapour barrier may be provided on top of panel30and then sealed together, such as by tape. Such strips may have a width equal to the spacing between adjacent rebar pairs (e.g., rebar pair52aand52band rebar pair52band52c) so that the strips are positioned such that intermediate portions48of shear connectors44are positioned between abutting edges of such strips.

As exemplified inFIG. 10, concrete may then be poured on top of vapour barrier24to complete the formation of the panel10. The concrete may be poured so as to completely fill form60or to provide a desired thickness of concrete for concrete panel10. Preferably, the concrete has a thickness such that second portion50of shear connector44is positioned internally in concrete panel18.

In a preferred embodiment, rebar is also provided in concrete panel18. Preferably, the rebar associated with shear connectors44so as to secure shear connectors44in position while concrete is poured into form60to form concrete layer18. For example, after vapour barrier24has been positioned in form60, rebar may be secured to, e.g., second portions50of shear connectors44. Any attachment means known in the art may be used. Accordingly, second portions50of shear connectors44are secured in position and will remain in position as the concrete is poured into position and, preferably, tamped or otherwise compacted to reduce and preferably prevent the formation of voids in concrete panel18.

Once the concrete of concrete panel18has cured to a sufficient degree, form60may be removed and the resultant panel10may then be stored for later use, shipped for use at a building site or used at the building site at which panel10is fabricated.

It will be appreciated that panel10may be constructed by pouring the inner concrete panel18in the bottom of the form60. The subsequent construction steps would be in the reverse order of those set out in the description ofFIGS. 5-10.

The citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.