Abstract:
A drainage system for use in concrete masonry unit (CMU) wall construction comprises a tray unit of a size corresponding to size of CMUs, to be received beneath a course of CMUs, in use. The tray unit comprises opposite side flanges to abut a superjacent CMU and supporting a pan therebelow. A strip of water permeable material is attached to an upper surface of the pan and extends transversely beyond a front edge of the pan. A block of water permeable material is positioned above the pan and extends upwardly into a hollow core of a CMU. The water permeable material of the strip and the block has a porosity sufficient to permit water to pass there through but substantially insufficient to permit mortar and debris to pass there through so that water in a hollow core of a CMU drains through the strip.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to concrete masonry unit wall construction and, more particularly, to a drainage system therefor.  
         BACKGROUND OF THE INVENTION  
         [0002]    Single wythe masonry walls are constructed using concrete masonry units (CMUs). CMUs are sometimes referred to as cinder blocks. A CMU consists of a hollow rectangular building block typically having a central web providing two vertical cores or cavities. In singly wythe masonry wall construction a foundation is formed, typically of concrete. The wall is formed by laying the CMUs in alternating fashion in multiple courses depending on the height of the wall. Owing to the construction, the vertical cores of CMUs are aligned to provide a continuous channel from the top of the wall down to the foundation. Mortar is used in joints to join the CMUs.  
           [0003]    Cracks in the CMUs can allow water to enter the cores. Moisture can also condense in the cores under changing temperatures. Either way, water may collect in the cores in the CMUs.  
           [0004]    The presence of moisture in the cores is undesirable for a number of reasons. First, the trapped moisture can degrade the structure. Second, the presence of water under freezing temperatures may also cause cracks in the wall when water expands as it freezes. Trapped water in the cores in the CMUs may cause the CMUs to become discolored, and may even migrate into the dwelling.  
           [0005]    To overcome the problems associated with water trapped within the CMU cores, weep holes are commonly included along the base of the outer side of the CMUs in the lowermost course. The weep holes allow water to pass from the core to drain outside the wall structure. A flashing disposed in the core directs the collected water toward the weep holes.  
           [0006]    During construction of a single wythe masonry wall, excess mortar and other debris can and does fall into the cores. When the CMUs are stacked during the erection of the wall, for example, mortar droppings are squeezed into cores within the CMUs. The excess mortar, as well as other debris, such as insulation, drops to the base of the core, and can block weep holes.  
           [0007]    One known solution is to construct a CMU drainage course consisting of two wythes separated by a cavity sized to accommodate through wall flashing and blocks of water permeable material. This solution uses different style concrete blocks in the drainage course.  
           [0008]    Another known solution, shown in U.S. Pat. No. 6,202,366, uses a collection pan under each CMU core of a selected course to collect water in the core. A weep channel on the pan drains the water to the exterior of the wall. This solution requires a collection pan for each core. Also, each pan must be aligned prior to applying mortar so that once a subsequent course is laid each pan is properly aligned with the CMU.  
           [0009]    The present invention is directed to solving one or more of the problems discussed above, in a novel and simple manner.  
         SUMMARY OF THE INVENTION  
         [0010]    In accordance with the invention, there is provided a drainage system for use in concrete masonry unit (CMU) wall construction.  
           [0011]    Broadly, the drainage system comprises a tray unit of a size corresponding to size of CMUs, to be received beneath a course of CMNs, in use. The tray unit comprises opposite side flanges to abut a superjacent CMU and supporting a pan therebelow. A strip of water permeable material is attached to an upper surface of the pan and extends transversely beyond a front edge of the pan. A block of water permeable material is positioned above the pan and extends upwardly into a hollow core of a CMU. The water permeable material of the strip and the block has a porosity sufficient to permit water to pass therethrough but substantially insufficient to permit mortar and debris to pass therethrough so that water in a hollow core of a CMU drains through the strip.  
           [0012]    It is a feature of the invention to provide an adhesive layer on the opposite side flanges to adhere to a CMU. The adhesive may be on an upper surface of the opposite side flanges to adhere to a superjacent CMU  
           [0013]    It is another feature of the invention that the pan is sloped downwardly toward the front edge.  
           [0014]    It is still another feature of the invention to provide front and rear flanges extending between the side flanges to support the pan. The front flange includes a notch receiving the strip. The strip extends forwardly of the front flange.  
           [0015]    It is still another feature of the invention that the water permeable material is a non-water absorbent randomly oriented fibrous material.  
           [0016]    It is still a further feature of the invention that the block is T-shaped having a top part wider than a CMU core and a bottom part narrower than a CMU core.  
           [0017]    It is still another feature of the invention that the block is taller than a CMU so that the top part bends to conform to a CMU core and the bottom part extends horizontally to cover a portion of the strip disposed in a CMU core.  
           [0018]    There is disclosed in accordance with another aspect of the invention a drainage system for use in CMU wall construction, each CMU including a pair of hollow cores. The drainage system comprises a generally rectangular tray unit of a size corresponding to size of CMUs, to be received beneath a course of CMUs, in use. The tray unit comprises a perimeter flange, a web flange connected transversely centrally within the perimeter flange, the flanges to abut a superjacent CMU, and a pair of pans each supported between the perimeter flange and web flange and each on opposite sides of the web flange. A pair of strips of water permeable material are each attached to an upper surface of one of the pans and extending transversely beyond a front of the perimeter flange. A pair of blocks of water permeable material are positioned above the pans and extending upwardly into hollow cores of a CMU, in use.  
           [0019]    There is disclosed in accordance with a further aspect of the invention a drainage system for use in CMU wall construction comprising an elongate tray element of one piece construction to be received beneath a course of CMUs, in use, comprising a plurality of aligned, generally rectangular tray units each of a size corresponding to size of cores. Each tray unit comprises a perimeter flange to abut a superjacent CMU, and a pan supported within the perimeter flange. A plurality of strips of water permeable material are each attached to an upper surface of one of the pans and extend transversely beyond a front of the perimeter flange.  
           [0020]    It is a feature of the invention that each perimeter flange comprises front and rear flanges extending between opposite side flanges to support the pans. The front flange includes a notch receiving the strip.  
           [0021]    It is still another feature of the invention that at least one side flange of each tray unit adjoins a side flange of an adjacent tray unit.  
           [0022]    It is still a further feature of the invention that adjoining side flanges are separated by a score line.  
           [0023]    Further features and advantages of the invention will be readily apparent from the specification and from the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is an exterior perspective view of a drainage system in accordance with the invention used in a single wythe masonry wall formed by courses of concrete masonry units (CMUs);  
         [0025]    [0025]FIG. 2 is a perspective view of a tray of the drainage system of FIG. 1;  
         [0026]    [0026]FIG. 3 is a sectional view taken along the line  3 - 3  of FIG. 2;  
         [0027]    [0027]FIG. 4 is a sectional view taken along the line  4 - 4  of FIG. 2;  
         [0028]    [0028]FIG. 4A is a sectional view, similar to FIG. 4, for a tray according to an alternative embodiment of the invention;  
         [0029]    [0029]FIG. 5 is a perspective view, similar to FIG. 2, illustrating the tray with a peel and stick adhesive layer;  
         [0030]    [0030]FIG. 6 is a side elevation exploded view illustrating the tray of FIG. 2 prior to attachment to a CMU;  
         [0031]    [0031]FIG. 7 is a side elevation view, similar to FIG. 6, illustrating the tray attached to the CMU;  
         [0032]    [0032]FIG. 8 is an elevation view of a block of water permeable material in a static state used in the drainage system of FIG. 1;  
         [0033]    [0033]FIG. 9 is a perspective view of the block of FIG. 8 bent to conform to walls of a CMU hollow core;  
         [0034]    [0034]FIG. 10 is a perspective view, with a CMU removed for clarity, illustrating relationship between the block and the tray in accordance with the invention;  
         [0035]    [0035]FIG. 11 is a plan view of a tray element in accordance with an alternative embodiment of the invention comprising a plurality of trays;  
         [0036]    [0036]FIG. 12 is a perspective view of a tray in accordance with the invention to accommodate a rebar; and  
         [0037]    [0037]FIG. 13 is a perspective view of an adapter used with the trays in accordance with the invention to accommodate rebar. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]    Referring to FIG. 1, a drainage system  20  is illustrated in connection with concrete masonry unit (CMU) wall construction. In the illustrated embodiment of the invention, the drainage system  20  is used in a single wythe masonry wall construction  22  formed by courses  24  of CMUs  26 . The wall construction  22  is used on a building structure including a foundation wall  28 . In the illustrated embodiment of the invention, the foundation wall  28  comprises a concrete wall. The foundation wall could be of block construction, as will be apparent to those skilled in the art.  
         [0039]    Referring also to FIG. 10, the drainage system  20  comprises a tray  30  and a pair of blocks  32  of water permeable material.  
         [0040]    CMUs  26  most typically have a nominal height of eight inches, a nominal length of sixteen inches and come in nominal widths of eight, ten or twelve inches. Actual sizes are about ⅜ inches less to allow for a ⅜ inch mortar joint. The CMU  26  comprises a hollow concrete block  34  having a web  35  to provide a pair of vertically extending hollow cores or cavities  36  therethrough. The hollow cores or cavities  36  are typically about five inches square. In conventional single wythe masonry wall construction, a first course  24 - 1  of CMUs  26  is secured to the foundation wall  28  with a layer of mortar. Mortar is also provided between adjacent CMUs  26 . A layer of mortar is then placed upon the first course  24 - 1  and the second course  24 - 2  is laid on the first course  24 - 1 . Again, mortar is provided between each CMU  26 . The CMUs  26  in each course are typically offset from one another as illustrated in FIG. 1. As a result, the vertical cores  36  in any course  24  are aligned with the vertical cores  36  in other courses  24  to provide a continuous channel from the top of the wall down to the foundation wall  28 , as is well known.  
         [0041]    Referring to FIGS. 2-4, the tray  30  comprises a tray unit  38  and a pair of strips  40  of water permeable material. The tray unit  38  is of one piece molded plastic construction and has a length and a width less than that of a CMU so that it can be set in mortar and the mortar will set up and secure the tray unit  38  in position. For example, the length of the tray unit  38  may be on the order of twelve inches and the width of the tray unit  38  may be on the order of six inches for an eight inch wide CMU.  
         [0042]    The tray unit  38  comprises a peripheral flange  42  formed by a front flange  44 , a rear flange  46 , a right side flange  48  and an opposite left side flange  50 . A web flange  52  is connected transversely, centrally within the perimeter flange  42  and in particular extends from a center of the rear flange  46  to a center of the front flange  44 . The perimeter flange  42  and the web flange  52  are U-shaped in cross section, as shown in FIGS. 3 and 4, and open downwardly. A pair of pans  56  and  58  are supported between the perimeter flange  42  and the web flange  52  each on opposite sides of the web flange  52 . Particularly, the first pan  56  is supported in an area bound by the left side flange  50 , the front flange  44 , the web flange  52  and the rear flange  46 . Similarly, the right pan  48  is supported in an area bound by the web flange  52 , the front flange  44 , the right side flange  48 , and the rear flange  46 . The pans  56  and  58  are generally rectangular in shape and of a size at least as large a shape of the hollow cores  36 . The perimeter flange  42  and web flange  52  define an upper surface  60 . In the embodiment of FIGS. 2-4, the upper surface  60  is planar and the pans  56  and  58  are likewise planar and parallel to the upper surface  60 . FIG. 4A illustrates a tray unit  38 ′ in accordance with an alternative embodiment of the invention. This embodiment differs in that the pans, including a left pan  56 ′, are sloped from the rear flange  46  toward the front flange  44 . Indeed, depending on the slope, the rear flange  46  may even be eliminated. The sloped pans enhance drainage toward a front edge  62  of the pan  56 ′ and thus the front flange  44  to enhance drainage. The pan  56 ′ could also be sloped from the sides toward the strip  40 .  
         [0043]    In the illustrated embodiment of the invention, the tray unit  38  has a uniform wall thickness on the order of {fraction (1/16)} inch. Alternatively, the flanges could be solid plastic.  
         [0044]    The front flange  44  includes a pair of notches  64  and  66 . The notch  64  is associated with the left pan  56  and is centered between the left side flange  50  and the web flange  52 . Similarly, the right notch  66  is associated with the right pan  58  and is centered between the web flange  52  and the right side flange  48 .  
         [0045]    The strips  40  are of a water permeable material having a thickness in the range of about ⅛ inch to ½ inch with ¼ inch being typical. The strips  40  are adhered in any known manner to the pans  56  and  58  and extend transversely beyond the front edge  62  of the pans  56  and  58  and also beyond front flange  44 . The strips  40  function to permit water to pass therethrough and to substantially prevent mortar and other debris from passing therethrough. The material is preferably a non-absorbent water-permeable, fibrous mesh material formed with circuitous (non-linear) pathways. The material is preferably a mass of random filament-type plastic fibers. The strip may also include an outer layer of backing material. The backing material may be a finely woven paper like material which will pass water but not fine debris, such as vermiculite or the like. Overall, the material is sufficient to catch and support mortar and debris without significant collapse, but allow water to pass freely therethrough. The strips  40  may be secured with a suitable adhesive or molded in situ with the tray unit  38 .  
         [0046]    Referring to FIG. 5, the tray unit  38  includes an adhesive layer  68  on the upper surface  60 . The adhesive layer  68  is initially covered by a removable film  70  to provide a peel and stick configuration. In the illustrated embodiment of the invention, the adhesive layer  68  covers the entire upper surface  60 . Alternatively, the adhesive layer could be provided only on the side flanges  48  and  50  and the web flange  52 , as necessary or desired. Likewise, the adhesive layer could be provided on a bottom surface, particularly when used with solid flanges.  
         [0047]    To install the tray  30 , it is positioned below a CMU  26 , as illustrated in FIG. 6, after removal of the protective sheet  70 . Thereafter, it is pressed against the bottom of the CMU  26  so that the adhesive layer  68 , see FIG. 5, causes the tray unit  38  to adhere directly to the CMU  26 . This allows the tray  30  to be properly aligned with the CMU  26  so that the pans  56  and  58  are positioned directly below the cores  36 . As is apparent, the tray  30  could be turned upside down and secured to an upside down CMU which is then turned over to be laid on the foundation wall  28 . More particularly, a layer of mortar is applied to the top of the foundation wall  28  in a conventional manner and the CMU  26  with the tray  30  installed thereon is laid in the mortar for to set up in a conventional manner. Thereafter, the strips  40  extend outwardly of the CMUs  26 , as generally illustrated in FIG. 1.  
         [0048]    As illustrated, the strips  40  are of a length to extend forwardly of the CMU  26  and then optionally be cut off after the mortar sets or be provided with a score line to be broken off.  
         [0049]    Referring to FIG. 8, the block  32  comprises a T-shaped sheet  72  of water permeable material, similar to material of the strips  40 . The sheet  72  has a thickness in the range of about ⅛ inch to ½ inch with ¼ inch being typical. The sheet  72  has a top part  74  wider than a CMU core  36  and a bottom part  76  narrower than a CMU core  36 . For example, with a CMU having a 5×5 inch core, the top part  74  might be about six to eight inches across and about seven inches tall, while the bottom part  76  might be on the order of four inches across and four inches tall. The block  32  is then stuffed in a core  36  of the first course  24 - 1  by bending the bottom part  76  so that it extends horizontally and thus perpendicular to the top part  74  and then curving opposite ends  78  and  80  of the top part  74  to conform to the walls of the core  36 . As a result, the curve of the top part  74  gives stability to the mesh material to withstand impact of falling mortar. The proper type of mesh, as described above, will provide a prickly adhesion to the porous walls of the CMUs  26 . The horizontal bottom part  76  covers the drainage strip  40  to protect it from being plugged by mortar droppings or granular or foam insulation.  
         [0050]    [0050]FIG. 10 illustrates a tray unit  30  with one block  32  installed over the left pan  56 . For clarity, the CMU  26  is not shown in FIG. 10. As is apparent, the block top portion  74  will be supported above or by the tray unit upper surface  60 . The bottom portion  76  could be resting directly atop the strip  40  or be supported slightly above the strip  40 , as necessary or desired.  
         [0051]    As described, the tray  30  is adapted to function with a dual core CMU, such as a CMU  26 . The tray unit  38  could be provided with a single pan with two strips  40  as by eliminating the web flange  52  for use with dual cores, or could be provided in half the size with only a single pan for use with a smaller CMU having only a single core.  
         [0052]    Referring to FIG. 11, a tray element  90  according to an alternative embodiment of the invention is illustrated. The tray unit  90  comprises a plurality of trays  30  formed together of one piece construction to be received beneath a plurality of CMUs  26  in a course. In the illustrated embodiment of the invention, the tray element  90  comprises six trays  30  integrally joined together so that at least one side flange of each tray  30  adjoins a side flange of an adjacent tray. A score line  92  could be provided between adjacent trays  30  for separability in the field if fewer than six trays  30  are required. Also, a score line  92  could be provided between pans  56  and  58  of each tray  30  in the event that an odd number of cores are present. In all other respects, the trays  30  are as described above relative to FIGS. 2-5. As is apparent, the tray element  90  could have more or less than six trays  30 .  
         [0053]    After installation, a block  32  of water permeable material will be positioned above the tray element  90  at each core  36 , as described above.  
         [0054]    Referring to FIG. 12, a tray  100  is adapted to accommodate rebar in a reinforced wall. The tray unit  100  comprises a pan  102  connected to a left side sloped end wall  104 . The end wall  104  includes a semicircular notch  106  to receive a rebar. The notch  106  should be sized larger than the rebar to allow field placement of the tray  100 . Front and rear flanges  108  and  110 , respectively, extend across the pan  102  and the end wall  104  and are connected by a right side flange  112 . A notch  114  in the front flange  114  receives a strip  40  of water permeable material, as above. As is apparent, the end wall  104  and side flange  112  could be reversed for installation on the opposite side of the rebar.  
         [0055]    [0055]FIG. 13 illustrates an adapter  120  for use with the tray  30  of FIG. 2 to accommodate rebar. The adapter  120  comprises a plate  122  having a notch  124  on one side edge  126  and a downwardly depending lip  128  on an opposite edge  130 . The lip  128  can hook over a side flange  48  or  50  so that the notched edge  126  is away form the pan  58  or  56 .  
         [0056]    Though the block  32  is described as a T-shaped sheet element, other configurations for the block  32  could also be used. These blocks include triangular elements, cylindrical elements, as well as other shapes. Such shapes and the water permeable material are described in applicant&#39;s pending application Ser. No. 10/393,689, filed Mar. 21, 2003, the specification of which is hereby incorporated by reference herein.  
         [0057]    Thus, in accordance with the invention, there is provided a drainage system including a tray unit including a pan with a strip of water permeable material attached to an upper surface of the pan and a block of water permeable material position above the pan. In one embodiment, a peel and strip adhesive is applied to the tray unit so that it is self adhering to a CMU prior to laying of the CMU on a foundation wall.