Abstract:
An improved method of forming an insulated poured concrete wall, a system for forming an insulated poured concrete wall, and an insulated poured concrete wall are provided. The system includes spaced-apart wall forms defining a cavity, a plurality of insulating panels adjacent at least one of the opposing wall surfaces, and a plurality of the elongate retaining strips between adjacent insulating panels, wherein each of the elongate retaining strips includes a portion that projects into the cavity and/or each of the elongate retaining strips has at least one notch through which a wall tie passes. The system allows building materials such as drywall, siding, paneling, and the like, as well as heavier objects, such as cabinets to be more stably and durably secured to an insulated poured concrete wall, and facilitates construction of an insulated concrete wall using fewer components and less labor.

Description:
FIELD OF THE INVENTION 
     This invention relates to insulated concrete wall systems, and more particularly to poured concrete wall systems in which a thermal insulation panel is joined to the concrete wall by an elongate retaining strip having edges engaging grooves formed in opposing vertical edges of the insulating panels. 
     BACKGROUND OF THE INVENTION 
     Poured concrete walls are formed by pouring or pumping uncured concrete between rigid planar forms generally made of wood, aluminum, steel or a combination of these materials. Two series of coplanar forms are typically held in spaced-apart, parallel relationship by retaining ties to create a cavity in which the poured concrete wall is formed. 
     Poured concrete walls can be constructed more quickly and at a lower cost than comparable alternative wall structures, while providing excellent durability, structural integrity, and other aesthetic and functional characteristics. However, poured concrete walls have relatively poor thermal insulating properties, and methods for incorporating insulative material in a poured concrete wall often have been difficult, requiring excessive time, labor and cost. Some of these methods require unconventional wall forms which are more costly to obtain and use than conventional wall forms. 
     U.S. Patent Application Publication No. U.S. 2001/0000844 A1 (incorporated in its entirety herein) describes an insulated concrete wall structure having embedded wall ties and a series of elongate retaining strips positioned between vertically spaced wall ties. Insulating panels are located between the horizontally spaced wall ties and are retained in position by the retaining strips. An advantage of this system is that an insulated poured concrete wall can be constructed using conventional wall forms in approximately the same amount of time as conventional uninsulated poured concrete walls. The resulting insulated poured wall system can be constructed at a lower cost than other known insulated poured concrete wall systems. Additionally, it is disclosed that the retaining strips allow building material such as drywall or paneling to be attached to the face of the insulating panels once the wall forms are removed and the wall is completed. However, this wall system is deficient in certain respects. First, the elongate retaining strips are not secured directly to the concrete wall, but instead are secured at opposite ends of the retaining strip to wall ties by notches formed in the wall ties. As a result, the elongate retainers are retained along their vertical edges between adjacent insulation panels and at their upper and lower edges between the notches in the vertically spaced-apart ties. This can allow some freedom of movement of the elongate retaining strips when building materials, especially heavy objects such as cabinets, are attached to the elongate retainers. In extreme cases, this can cause structures supported on the elongate retainers to pull away from the wall. Accordingly, there is a need for a more rigid insulation panel retainer that is capable of securely supporting heavier loads. 
     Another problem with the insulated concrete wall system disclosed by Patent Publication No. U.S. 2001/0000844 A1 is that it requires a plurality of elongate retaining strips between adjacent insulation panels. More specifically, one retaining strip is located between each set of vertically spaced-apart ties. The publication states that the height or length of the retaining strips is dependent upon the distance between adjacent ties, but is typically about one foot in length. Thus, for a typical poured concrete basement wall, eight retaining strips aligned vertically between adjacent insulation panels are needed. To reduce construction costs, it would be desirable to reduce the number of retainers that are required. Because the retainers are vertically spaced-apart, there are areas along the seam between adjacent insulation panels, in the vicinity of the ties, that are unavailable for engagement with a fastener to allow building materials to be attached. As a result, care must be taken to avoid locating fasteners in the area between vertically spaced-apart retaining strips when securing building materials such as drywall or paneling to the insulation panels. 
     Another disadvantage with the insulated concrete wall system described in United States Patent Application Publication U.S. 2001/0000844 A1 is that the flat surface of the elongate retaining strips can make it difficult to insert fasteners through the retaining strip. In particular, it can be difficult to initiate penetration of a drywall screw through the flat surface of the retaining strips. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved method of forming an insulated poured concrete wall, a system for forming an insulated poured concrete wall, and an insulated poured concrete wall. The invention allows insulated concrete walls to be formed more efficiently and at a lower cost by using fewer components. The invention also allows building materials such as drywall, siding, paneling, and the like, as well as heavier objects, such as cabinets, to be more stably and durably secured to the wall. 
     In accordance with one aspect of the invention, there is provided a system for forming an insulated poured concrete wall. The system includes spaced-apart wall forms forming opposing wall surfaces that define a cavity, a plurality of insulating panels arranged adjacent at least one of the opposing wall surfaces, and a plurality of elongate retaining strips between adjacent insulating panels, wherein each of the elongate retaining strips includes a portion that projects into the cavity. 
     In accordance with another aspect of this invention, a method of forming an insulated concrete wall is provided. The method includes arranging a plurality of wall forms in spaced relationship to form opposing wall surfaces defining a cavity, arranging insulating panels adjacent at least one of the opposing wall surfaces, arranging elongate retaining strips between adjacent insulating panels, wherein the elongate retaining strips engage edges of the insulating panels, and wherein a portion of each retaining strip projects into the cavity. 
     In accordance with another aspect of the invention, there is provided an insulated poured concrete wall comprising a concrete wall having opposing wall surfaces, a plurality of spaced-apart, elongate retaining strips, the elongate retaining strips having a portion embedded in the concrete wall with the length direction of the retaining strips extending vertically. A plurality of insulating panels is provided, with each panel being held between laterally spaced-apart retaining strips. 
     In accordance with another aspect of the invention, a system for forming an insulated poured concrete wall includes spaced-apart wall forms forming opposing wall surfaces that define a cavity, a plurality of vertically and horizontally spaced-apart wall ties extending between the opposing wall forms, a plurality of insulating panels arranged adjacent at least one of the opposing wall surfaces, and a plurality of elongate retaining strips between adjacent insulating panels, with each elongated retaining strip having at least one notch through which a wall tie passes. 
     In accordance with another aspect of the invention, there is provided a method of forming an insulated poured concrete wall using a plurality of elongate retaining strips, wherein each elongate retraining strip includes at least one notch that allows a wall tie to pass through. 
     Another aspect of the invention provides an insulated poured concrete wall comprising a concrete wall having opposing wall surfaces, a plurality of vertically and horizontally spaced wall ties contained within the concrete wall and extending between the opposing wall surfaces, a plurality of insulating panels arranged adjacent at least one of the opposing wall surfaces, and a plurality of elongate retaining strips between adjacent insulating panels, each elongate retaining strip having at least one notch through which a wall tie passes. 
    
    
     These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an insulated concrete wall system in accordance with the invention. 
     FIG. 2 is an elevational view of the wall system shown in FIG.  1 . 
     FIG. 3 is a front view of a retaining strip used in the wall system of this invention. 
     FIG. 4 is a side view of the retaining strip shown in FIG.  3 . 
     FIG. 5 is a cross-sectional of the retaining strip shown in FIGS. 3 and 4. 
     FIG. 6 is a horizontal cross-sectional view of a poured concrete wall in accordance with this invention. 
     FIG. 7 is a transverse cross-sectional view of an alternative-retaining strip in accordance with this invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In FIG. 1, there is shown a perspective view of a portion of a poured wall forming system  10  embodying the present invention. The system includes a plurality of wall forms  12  which are arranged to form two series of coplanar wall forms held in opposing spaced-apart, parallel relationship. Adjacent wall forms  12  are held in a coplanar relationship by connecting pins  14 , and the two series of coplanar wall forms are held in opposing spaced-apart parallel relationship by wall ties  16 . Wall forms  12  may be constructed of wood, aluminum, iron, steel, or various other materials or combinations thereof. 
     The forms  12  are typically from about 2 to 6 feet wide and from about 2 to about 10 feet high. Connecting pins  14  are well known in the art. Insulating panels  18  are positioned adjacent the interior surfaces of at least ones of the series of wall forms  12 . Grooves  20  are formed in opposing vertical edges of insulating panel  18 . A long edge  28  of a T-shaped retaining strip  22  is received in groove  20 . Insulating panels  18  are held in place at their edges between laterally spaced-apart retaining strips  22 . As shown in FIG. 2, rather than extending between vertically spaced-apart ties  16 , retainer  22  may extend the full height of the poured wall, e.g., such as 8 or 9 feet. This is achieved by providing a series of vertically spaced-apart notches  24  through which ties  16  pass. Thus, rather than extending between ties  16 , retaining strip  22  extends uninterrupted past wall ties  16 . Retaining strips  22  are temporarily held in place by engagement of notches  24  with notches in the edges of wall ties  16  until the concrete has been poured and cured. This reduces the number of retaining strips  22  which are needed, thus simplifying installation and reducing construction costs. While it is preferred that a single retaining strip  22  extend from floor to ceiling, i.e., the full height of a poured concrete wall, the benefits of the invention can be achieved using a plurality (e.g., two or three) of retaining strips  22  which together extend the full height of the poured concrete wall. In other words, notches  24  which allow ties  16  to pass through the retaining strip  22  facilitate a reduction in the number of retaining strips needed and thereby simplify and reduce the costs associated with installation of the insulated poured wall system. 
     In addition to reducing the number of retaining strips needed, the retaining strips  22  provide a continuous strip or stud that allows building materials such as drywall or paneling to be attached with fasteners such as screws or nails at any elevation, including an elevation at which a wall tie  16  is present. 
     A preferred embodiment of a retaining strip  22  in accordance with the invention is shown in further detail in FIGS. 3-5. As shown in FIG. 5, retaining strip  22  has a T-shaped cross-sectional profile, including a web portion  30 , an enlarged (e.g., flared or bulbous) anchor portion  32  at one end of web  30 , and a flange portion  34  at the other end of web  30 . Flange portion  34  is at a right angle with respect to web portion  30  and includes a left (with respect to the drawing shown in FIG. 5) side  36  and a right side  38 . The left side (or half) of flange  34  constitutes a continuous, uninterrupted, rectangular strip, whereas the right side (or half) of flange portion  34  includes spaced-apart notches  24  for accommodating wall ties  16 , i.e. for allowing wall tie  16  to pass through or around the retaining strip  22 . 
     As shown in FIG. 6, which is a vertical cross section of a finished wall after concrete  40  has been poured between wall forms  12  but before the forms  12  have been removed, anchor portion  32  of retaining strip  22  is embedded within the concrete wall  40 . The T-shaped profile provides improved rigidity and strength for hanging wall coverings such as drywall, paneling, siding (when the insulation is on the exterior side of the wall), etc. Improved rigidity and strength is also achieved by embedding a portion  32  of the retaining strip  22  in concrete wall  40 . The resulting structure shown in FIG. 6, in addition to accommodating wall coverings, can support relatively heavy loads such as large wooden cabinets and the like without warping, buckling, distorting or pulling away from the wall on account of the additional rigidity and strength provided by web  30  and by embedding the anchor portion  32  of retaining strip  22  in concrete wall  40 . 
     In order to facilitate easier insertion of fasteners into flange portion  34  of retaining strip  22 , flange portion  34  is provided with a serrated surface as shown in FIG.  5 . The serrations help guide a fastener into the flange portion  34  making it easier to initiate penetration of a threaded fastener through flange portion  34 . 
     The wall structure shown in FIG. 6 is constructed by first assembling the wall forms  12  with the connecting pins  14  and wall tie  16  as shown in FIG.  1 . Thereafter, a plurality of insulating panels  18  and retaining strips  22  are positioned inside the wall forms  12  and along one of the two parallel wall surfaces. The retaining strips  22  are temporarily held in place by the grooves  20  in insulation panels  18 . 
     Insulating panels  18  can be made of generally any relatively rigid insulating material, such as rigid polyurethane foam or rigid polystyrene foam. Panels  18  can be of generally any width, typically from about 2 feet to about 6 feet, and generally any height, typically from about 2 feet to about 10 feet, and can have any desired thickness, typically from about 2 to about 3 inches. 
     The retaining strips  22  can be made of any of various suitable materials such as wood, plastic or metal. The web portion  30  and flange portion  34  of retaining strips  22  are relatively thin, typically about ⅛ inch in thickness. The width of the web portion  30  and the flange portion  34  is typically from about 1-½ inches to about 4 inches. Preferably, the retaining strips  22  are made of a material to which conventional fasteners such as screws and nails can be secured. 
     To create the insulated poured concrete wall, uncured concrete is poured into the cavity formed between the two series of coplanar wall forms  12 . The expression “poured” includes any method or manner in which uncured concrete can be deposited into the cavity between wall forms  12 , whether by hand, from the concrete truck chute, from a pumping system, etc. Once the concrete has set (typically from about 12 to about 24 hours), the forms  12  are removed by releasing the connecting pins  14  from the holes of the walls ties  16 . The forms are then pulled away from the concrete wall. Once the pins and forms are removed, the concrete wall remains with the wall ties  16  embedded within the concrete wall, with insulating panels  18  secured to at least one side of the concrete wall. A portion of wall ties  16  that extends outwardly from the wall surface is typically broken or snapped off. 
     Although the wall structure shown in the drawings includes insulation panel  16  on only one side of concrete wall  40 , the method of this invention can be employed to provide insulation on both sides of concrete wall  40 . An insulating surface may be provided on only the exterior side of the poured concrete wall such as to facilitate use of flange  34  of retainer  22  to attach exterior siding to the wall. Insulating panels can be provided only on the interior side of the wall with flange portion  34  of retaining strip  22  used for attaching interior drywall, paneling, or the like. When the wall system and method of this invention is used for insulating both sides of a poured concrete wall, the retaining strips on the exterior side of the wall can be used for securing exterior siding to the wall, and the retaining strips on the interior side of the wall can be used for securing drywall or the like. 
     In FIG. 7, there is shown an alternative embodiment of the retaining strip  122 . Retaining strip  122  includes a segmented web portion including a web portion segment  130 A extending between an exterior flange  134  and a parallel interior flange  135 , and a second web portion segment  130 B extending from interior flange  152  to an enlarged anchor portion  132 . Depending on the dimensions of retaining strip  122 , and the dimensions of insulating panel  18 , insulating panel  18  may be retained between flanges  134  and  152 , or flanges  134  and  152  may engage parallel grooves in the edges of adjacent panels  18 . As another alternative one or the other of flanges  134  and  152  may be engaged in a groove formed in the edge of an insulating panel  18 , while the other flange engages one or the other side of panel  18 . The parallel flange arrangement of retaining strip  122  allows a fastener such as a screw or nail to penetrate two parallel structures (flanges  134  and  152 ), whereby improved strength, rigidity and stability are provided for supporting objects, especially heavy objects such as cabinets and the like. 
     Web  30  may be scalloped (e.g., have a width that varies along the length of web  30 ) to provide a control joint that limits cracking of concrete wall  40  in a limited area. 
     The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents.