Abstract:
A universal and integrated water barrier system for exterior wood construction is provided. The system includes a universal waterproofing strip material that is adaptable for use in all of the various connection conditions encountered in exterior construction. The strip material is adaptable for use as a joist cap that is applied over the joist members for use between the joists and deck boards, a beam cap for doubled framing support members and a ledger cap that acts as a flashing protecting the gap between the ledger and adjacent structure as well as the ledger itself. Further, a stair stair stringer base is provided for use on the bottom of stair stair stringers to prevent the bottom the stair stringer from resting in contact with the earth. The system overcomes the disadvantages found in the prior art by providing an effective and simple method of excluding water from the critical structural connections within the construction system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is related to and claims priority from earlier filed provisional patent application No. 60/470,643, filed May 15, 2003. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates generally to a new system for protecting the wood construction typically found within a deck. More specifically, this invention relates to components that are installed during construction that are adapted to reduce rotting of wood framing members resulting from moisture that is trapped between these members and the adjacent materials to which they are fastened. This is particularly the case in areas such as those at the supporting end of a joist or a supported flooring plank.  
           [0003]    Outdoor structures, such as decks, gazebos, fences, furniture etc., are subject to a continuous cycle of harsh environmental conditions generated by mother nature including extensive and continuous exposure to ultraviolet radiation, heat, humidity, freeze/thaw cycles, rain and snow. This rapidly changing environment can have a large impact on the wood materials used and the connections made between the framing members causing degradation in the overall structure. The construction of this type of outdoor structure typically consists of, for example, a supporting structure formed of spaced joists or stair stringers, which in turn support decking that extends transverse to the direction of the joist supporting the decking. The supported decking is typically secured to the joist using standard fasteners, such as nails or screws, to obtain a sound structure. Further, to make connections to surrounding structure, such as to attach the structure to the side of an adjacent building, a ledger is connected in a similar fashion. Finally, stair stringers leading from the deck and ultimately resting on the ground are also provided to allow access onto and off the deck. Each one of these connections and contact points provides a potential problem area that could ultimately lead to a degradation of the deck and stair structure.  
           [0004]    These connection areas are particularly susceptible to great stress, fatigue and eventual failure due to the nature of the wood material. Specifically, because of the nature of wood framing members, broad changes in temperature and humidity result in relatively high dimensional changes in the construction materials. When exposed to long periods of dry, cold weather the construction materials will shrink a great deal. When exposed to long periods of hot, humid weather or soaking rains, the construction materials will swell and expand. This movement is translated into the connections between all of the construction members causing the fasteners to move and the grain of the wood to open up allowing additional water infiltration.  
           [0005]    Often the exposed decking material is stabilized and protected somewhat from the weather by treating, such as by staining and water sealing with commercially available products. Further, the joists are typically made using a treated lumber to achieve a structure with a satisfactory useful life. However, even when treated lumber is utilized for the joists, the joists will eventually rot due to the moisture which becomes trapped between the supported decking where it bears upon the joists. In addition, even though the ends of the joists are usually not directly exposed to the atmosphere, the porous properties of wood cause the framing members to act as a wick and pull moisture from rain or condensation under the decking thereby also facilitating rotting.  
           [0006]    Many prior art systems are known to prevent moisture and humidity from migrating into a floor system from below, such as when a wood floor product is installed over a concrete basement floor. Typically, such a material is disposed between joists and the flooring to prevent moisture infiltration as well as to provide cushioning between the surfaces and to achieve a dampening of sound. For example, U.S. Pat. No. Re. 18,573 discloses a sound-deadening assembly where a felt strip is placed between a furring strip and the strips of flooring material. However, the felt strip in this application is not impermeable to water and is not effective to impede the rotting of the joist should it be utilized in an outdoor environment. Similarly, U.S. Pat. No. 3,385,018, issued to Harry teaches a support member that is particularly designed and dimensioned to conform to undulating surface of corrugated panels that are often used for walls, roofs etc. Disposed between each of the corrugated panels and the support member upon which they bear, there is an elastomeric filler strip of flexible, relatively dense material. The filler strip cushions the surfaces against one another, but does not serve to prevent moisture from becoming entrapped between the support member and the panels.  
           [0007]    U.S. Pat. No. 5,479,750 issued to Carlberg provides for the installation of a rigid plastic cap over the joist members before the installation of the deck members. The deck boards are then fastened in the traditional manner using screws or nails. This system has several drawbacks. First, the fasteners create punctures that are not sealed thereby still allowing water infiltration around the shaft of the fastener. Second, water flowing along the top of the cap is still entrapped beneath the deck boards. Finally, the system can only be applied to the single joist framing structural members and does not allow for larger members such as laminated or doubled up joists.  
           [0008]    There is therefore a need for a material and system for constructing a wood framed exterior structure that provides improved durability and enhanced resistance against exposure to water. Further, there is a need for providing a means for constructing a wood structure that is rot resistant while further enhancing the overall performance of the entire structure.  
         BRIEF SUMMARY OF THE INVENTION  
         [0009]    In this regard, the present invention provides for a universal and integrated water barrier system for exterior wood construction. The system includes a universal waterproofing strip material that is adaptable for use in all of the various connection conditions encountered in exterior construction. The strip material is adaptable for use as a joist cap that is applied over the joist members for use between the joists and deck boards, a beam cap for built-up framing support members and a ledger cap that acts as a flashing protecting the gap between the ledger and adjacent structure as well as the ledger itself. Similarly, the same concepts and materials in the present invention may also have applicability for use in numerous applications including but not limited to fence purlins and between various interconnected parts of outdoor furniture. Further, a stair stringer base is provided for use on the bottom of stair stringers to prevent the bottom of the stair stringer from resting in contact with the earth. The system overcomes the disadvantages found in the prior art by providing an effective and simple method of excluding water from the connections within the construction system.  
           [0010]    Specifically, the present invention provides a membrane composition that is produced in strip form. In the preferred embodiment, the composition of the membrane includes two layers of resilient membrane material applied to the top and bottom of the strip and may optionally include a reinforcing scrim material. In this fashion, the pliable membrane is reinforced in a dimensionally stable product for use in the present invention. On the bottom of the membrane, a layer of pressure sensitive adhesive is provided for adhering the material to the structure being protected. On top of the membrane, an optional bonding layer is provided. The bonding layer is a key element of the present invention. When placed into a structure, the material of the present invention is installed on top of the structural support elements. The deck members are then placed over the membrane elements. The top layer of the membrane includes a pliable and flowable material that is pressed into firm contact with the underside of the deck members and slightly up into the gap between adjacent deck board members. When the material flows in this manner and ultimately cures, a seal is formed between the protective membrane and the deck member preventing water from flowing between the membrane and the deck member. Further, the flowable material includes a curing agent to allow the exposed material between the deck boards to cure and form a durable, impact and UV resistant coating. By excluding water in this fashion, the life of the deck member is greatly enhanced. As can be seen the membrane of the present invention thereby provides both an effective cap for the framing members located below as well as preventing the infiltration and entrapment of water between the membrane and the decking members installed on top thereof.  
           [0011]    A further feature that differentiates the present invention from the prior art devices is that the membrane material is pliable and forms a seal around the locations where the fasteners are installed. This is important because the fasteners create a gap in the wood fibers that allows water infiltration. When the water is trapped in this manner, wood rot and damage from freeze/thaw cycles is accelerated. The membrane of the present invention is self-sealing around each of the fastener punctures to create a truly sealed assembly.  
           [0012]    Each of the components of the present invention is tailored to the specific location in which it will be installed. The same material structure is employed but alternate configurations are utilized. For joist caps, the profile is slightly wider than the standard 1½″ dimension of standard framing lumber. Similarly for doubled framing members, the profile is slightly wider than 3″ and optionally includes an additional bead of flowable material on the centerline of the bottom side of the material to fill the gap between the sistered framing members. The material is further scored on the underside to allow the overhanging sides to bend slightly downwardly creating a drip edge and includes registration marks thereon to assist the installer in aligning the material with the framing members onto which it will be installed. The ledger flashing is fashioned from the same material construction but is configured to act as a flashing under the siding material and project over the top of the ledger board effectively protecting the connection between the ledger board and the adjacent construction to which it is attached. Finally, the pan flashing typically used in door thresholds is configured to form a pan beneath the door installation and includes means for positive drainage to the exterior of the structure on the threshold portion, and preformed corner pieces that interface with the threshold to seal the corners of the opening once the pan flashing is installed.  
           [0013]    Additionally, the present invention discloses a rigid component for installation onto the bottom edge of a stair stringer member. Stair stringer base is a manufactured element that serves to isolate and elevate the stair stringer from contact with the ground allowing air circulation and reinforcing of the end of the stair stringer. Further, the base includes leveling screws or other fastening means such as inserts for casting into concrete to facilitate installation. The top portion of the stair stringer base includes periphery edges that extend upwardly to engage the bottom of the stair stringer member and further serve to provide a positive contact between the stair stringer bottom and a strip of membrane material provided on the top of the stringer base.  
           [0014]    Accordingly, it is an object of the present invention to provide a novel structure for wood construction applications which require protection against water infiltration. It is a further object of the present invention to provide a unique sealant strip for use in wood construction applications to prevent water infiltration between the structural members. It is yet a further object of the present invention to provide a sealant strip material that includes a fiber impregnating material thereon which creates an impervious seal when installed between structural members of a wood structure. It is an even further object of the present invention to provide an integrated system for constructing a wood structure which includes a sealant assembly for preventing water infiltration between the structural members. It is yet a further object of the present invention to provide an integrated system for use in wood construction that includes components that shield all of the critical connections and structural intersections from the infiltration of water.  
           [0015]    These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:  
         [0017]    [0017]FIG. 1 is a perspective view of the wood framing support for a deck including the waterproofing members of the present invention;  
         [0018]    [0018]FIG. 2 is a cross sectional view taken along the line  2 - 2  of FIG. 1;  
         [0019]    [0019]FIG. 3 is a cross sectional view taken along the line  3 - 3  of FIG. 1;  
         [0020]    [0020]FIG. 4 is a cross sectional view taken along the line  4 - 4  of FIG. 1; and  
         [0021]    [0021]FIG. 5 is a cross sectional view taken along the line  5 - 5  of FIG. 1.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Now referring to the drawings, the system for enhancing the durability of exterior structures having wood frame construction is shown and generally illustrated in FIGS. 1-5. While the preferred embodiment of the present invention is illustrated in the context of a wooden framed deck structure, this disclosure is not meant to be limiting on the application for the present invention but illustrative on one potential application. Further, while this particular embodiment is shown in the context of a wood deck, the present disclosure would be equally applicable in any exterior wood framing environment where such a connection as is detailed is encountered, these structures may include but are not limited to, decks, gazebos, docks, stages, fences and furniture.  
         [0023]    In general the generic components utilized in a wood framed structure are detailed in FIG. 1. The wood framed structure has a group of supporting structural members and a plurality of deck members extending over the supporting members to form a usable platform or surface. The primary supporting structural members are beams  2 . Typically the beams  2  are formed from two or more pieces of dimensional framing lumber  4  joined or sistered together. The beams  2  are supported at their ends and occasionally at additional intermediated points by vertical support members  6 . These vertical supports  6  may be posts as is shown in FIG. 1, or simply concrete piers upon which the bottom edge of the beams  2  rest. If the deck is free standing, the deck support will include at least two beams  2  in parallel spaced relation. If the deck is to be attached to an adjacent supporting structure  8 , the deck will use at least one beam  2  on one side and in place of a second beam  2 , a ledger board  10  will be mounted to the adjacent supporting structure  8  on the other side. The ledger board  10  is attached directly to the wall of the adjacent supporting structure  8  to create a rigid connection between the deck structure and the adjacent structure  8 , such as a house.  
         [0024]    A plurality of joist members  12  is installed to extend between the spaced apart beam members  2  or the beam and ledger members  10 . The plurality of joists  12  may be installed on top of both the beam members  2  and ledger members  10  or on the same level as the beam  2  and ledger members  10 , using construction means and techniques well known in the art. Further the joists  12  are rigidly fastened to these supporting members  2 ,  10 .  
         [0025]    The decking members  14  are then installed over the top of the entire structure spanning over and supported by a top supporting surface of each of the plurality of joists  12 , beams  2  and ledgers  10 . It is primarily the interface region where the deck members  14  contact these structural framing supports that is the concern of the present disclosure. These interface regions provide a region where water can become trapped resulting in the deterioration of the integrity of the wood structure.  
         [0026]    Two additional areas of concern are at the bottom of the stair stringer framing member  16  and at openings  18  in the adjacent support structure  8 . The stair stringer  16  supports a stairway that extends from the deck surface to the ground or second deck level beneath the deck. In most cases, the stair stringer  16  is supported directly on the ground  20  or on a concrete pad  22  at ground level. In either case, the bottom of the stair stringer  16  is in a location that allows the wood material to absorb a large quantity of water over an extended period of time. Additionally, where openings  18  are provided in the adjacent supporting structure  8  for access to the deck surface, such as patio doors, a special condition exists that requires a tailored flashing configuration to prevent water from infiltrating the adjacent structure  8 .  
         [0027]    Primarily, all of the framing members encountered in each one of the identified applications above is formed from wood. It is the nature of wood that the material is fibrous and susceptible to absorbing water into the fibrous structure. In particular, when water is maintained in a standing condition in contact with wood members for long periods of time, the wood will rot. The disclosure of the present invention is directed at protecting these susceptible regions in wood framed construction by preventing water migration between the various mated surfaces of the structural members.  
         [0028]    The present invention provides a plurality of water impervious barrier members that are installed onto a bearing surface of each of the ledger members  10 , beam members  2 , joist members  12  and stair stringer members  16 . The barrier members serve to protect their respective structural framing members by shielding the exposed surface of the members directly from contact with moisture and by preventing the migration of water into the connections between the structural members and the adjacent structures such as the deck members, the adjacent supporting structure or the ground.  
         [0029]    Generally, the barrier members have two different constructions. The first general group of barrier members has a similar construction and is particularly suited for use as joist cap members  24 , beam cap members  26 , ledger flashing  28  and pan flashing. The second barrier member type is particularly suited for use as a stair stringer support member  30 . While differing in actual construction, the application and purpose of the two different barrier members is the same. Specifically they are tailored to protect their respective framing support members from the adverse effects of prolonged exposure to standing water or against particular configurations resulting in water entrapment.  
         [0030]    Turning now to FIGS. 2 and 3, the first group of barrier members is generally illustrated in the context of a joist cap flashing  24  and a beam cap flashing  26 . The barrier member is a flexible resilient strip material configured for installation on top of a joist member  12  or a beam member  2  between the joist  12  or beam  2  and the decking members  14 . The barrier member is preferably a resilient membrane and more preferably a strip of bituminous material  32 ,  34  with a pressure sensitive adhesive (PSA) layer  38  on the bottom surface thereof and a fiber impregnating material  40  applied to a top surface thereof. To facilitate shipping and handling of the barrier members, a protective backing sheet will be applied to the top and bottom of the strip to maintain the integrity and cleanliness of the PSA  38  and the fiber impregnating material  40 . In this manner, immediately prior to installation, the backing strip is removed from the bottom surface to expose the PSA  38  and the barrier member is placed onto the framing member using guidelines printed on the top protective strip. The PSA  38  accordingly adheres the barrier member to the respective framing member preventing it from becoming dislodged during subsequent construction operations. Similarly, immediately prior to the installation of the decking members  14 , the protective backing strip is removed from the top surface of the barrier strip exposing the fiber impregnating material  40  and allowing it to contact the bottom surface of the decking members  14 .  
         [0031]    More preferably the barrier strips will be constructed having a central reinforcing layer  36  such as a fabric scrim, fiberglass mesh or UV stable plastic with a top  34  and bottom  32  bituminous layer applied thereto. While two particular constructions are detailed herein regarding the barrier members it can be appreciated that other constructions are possible and different layers may be added to tailor the product to other applications. In turn as was disclosed above, a PSA  38  layer is applied to the bottom surface of the bottom bituminous layer  32  and a fiber impregnating material  40  is applied to the top surface of the top bituminous layer  34 . This particular construction provides a highly durable barrier strip material that has improved dimensional stability and can endure relatively rough handling on a construction site while maintaining its integrity when installed and facilitates control of the exposure and use of each of the various layers depending on the particular application.  
         [0032]    In accordance with the present invention, the barrier strip members will be provided in widths that are slightly wider than the structural members to which they will be applied. As is generally known in the art, a dimensional framing member such as is used to form a joist  12  is typically 1½″ thick. Similarly, a beam  2  formed of two framing members  4  joined together is 3″ thick. When provided as a joist cap barrier member  24  the barrier strip will have a width that is slightly wider than the 1½″ thickness of the joist  12  while providing sufficient additional material to either side of the joist  12  to deflect water away from the joist member  12 . Similarly, when provided as a beam cap barrier member  26  the barrier strip will have a width that is slightly wider than 3″. Further, in either of the above applications, the bottom layer of material may include longitudinal score lines  42  defining a central region  44  that corresponds to the width of the framing member and two side regions  46 . The score lines  42  assist in aligning the barrier strip with the top of the framing member. Similarly guide or registration lines may be provided in the top release sheet to assist in aligning the barrier member. The score lines  42  also facilitate the bending of the side regions  46  relative to the central region  44 . In this manner, when the installer installs the joist cap  24  or beam cap  26  on the top surface of the framing member, the side regions  46  can be bent slightly downward thereby allowing water to be shed off of the central region  44  of the barrier strip and downwardly along the side regions  46  where the water reaches a drip edge formed by the end of the side region. This configuration prevents the water from migrating upwardly between the barrier member and the top of the structural framing member and generally allows the water to drip clear of the side of the wood framing members.  
         [0033]    Further, the barrier strip includes a fiber impregnating material  40  provided on the top surface thereof in the central region  44 . When the decking members  14  are installed onto the barrier strips, the bottom surface of the deck members  14  are in contact with the fiber impregnating material  40 . Preferably, the beads of fiber impregnating material  40  will be disposed transverse to the length of the barrier member. When fastened in place, the deck members  14  compress and distribute the fiber impregnating material  40  between the top surface  34  of the barrier strip and the bottom surface of the deck member  14 . Additionally, the fiber impregnating material  40  penetrates and seals the wood fibers of the deck members  14 . The fiber impregnating material  40  effectively forms a dam between the bottom surface of the deck members  14  and the top surface  34  of the barrier strips thereby preventing water infiltration at the connection. The fiber impregnating material  40  may further be provided with a curing agent that hardens the material after prolonged exposure to air. The curing agent causes the impregnating material  40  to harden in the areas where it is not in contact with a deck member  14  thereby forming an abrasion and ultraviolet radiation resistant coating over the top bituminous layer  34  of the barrier strip. Additionally, when used as a beam cap member  26 , the barrier strip may include an additional bead of fiber impregnating material  48  applied to the center of the bottom surface  32 . This bead of material  48  corresponds to the seam  50  between the two framing members  4  used to form the beam  2  and serves to form a waterproof dam between the two framing members  4  used to fabricate the beam  2 .  
         [0034]    Finally, the resilient nature of the bituminous layers  32 ,  34  provides the additional feature of being self healing or self flashing when punctured. This feature is particularly useful when the deck members  14  are fastened to the support members using screws or nails. When the fastener is installed, the fastener punctures the barrier member. The resilient nature of the barrier member causes the material adjacent the puncture to contract around the shaft of the fastener thereby waterproofing each fastener installation.  
         [0035]    The barrier member can also be formed into a specialty configuration for use in flashing a ledger board against an adjacent supporting structure. Turning to FIG. 4, a barrier strip formed for use as a ledger flashing  28  is shown. In this application, one score  42  is made in the bottom bituminous layer  32  and the second score  52  is made in the top bituminous layer  34 . The scores  42 ,  52  are spaced apart at a distance corresponding to the thickness of the ledger member  10 . The opposing scores  42 ,  52  allow one of the side regions  46  to be bent downwardly over the edge of the ledger  10  as was described above relative to joist  24  and beam cap  26  members. The other edge region  54  is scored to allow it to be bent upwardly as a flashing against the wall of an adjacent support structure  8 . When the siding is installed over the upwardly bent portion  54  of the flashing a complete flashing system is provided preventing water from infiltrating between the ledger  10  and the adjacent support structure  8  as well as preventing water from infiltrating the adjacent support structure  8  itself. When an opening  18  is provided in the adjacent support structure  8 , such as an opening  18  for a patio door, an additional pan flashing member  51  is provided that has a lip  53  that extends over and counter flashes the upwardly bent portion  54 . The base  55  of the pan flashing  51  provided with means for positive drainage in the base  55  of the pan flashing  51  that directs water towards the exterior of the structure causing positive drainage from under the threshold  57  of the door that is installed into the opening  18  in the adjacent structure  8 . Corner members  59  are also provided to enhance the performance of the pan flashing  51  and prevent migration of water laterally off the sides of the pan flashing  51 .  
         [0036]    The second category of barrier members is the stair stringer support member  30 . The stair stringer support member  30  has a polymer or metallic body with a top  56  and bottom surface  58 . The stair stringer support  30  is configured and arranged to be installed onto the bottom of a stair stringer  16  framing member to rigidly support the stair stringer  16  and prevent the stair stringer  16  from contacting the ground  20  or the contact pad where the bottom of the stair is to terminate. The top surface of the stair stringer support  56  has a wall  60  extending upwardly therefrom. The wall  60  has a tapered profile ending in a knife-like edge. When the stair stringer support  30  is installed onto the bottom of the stair stringer  16 , the wall  60  engages the bottom of the stair stringer  16  to prevent water from infiltrating between the top surface  56  of the stair stringer support  30  and the bottom of the stair stringer  16 . Holes  62  are provided through the body of the stair stringer support  30  so that fasteners  64  can be installed to firmly attach the stair stringer support  30  to the stair stringer  16 . It is anticipated that as the fasteners  64  are installed, they will draw the stair stringer support  30  tightly against the base of the stair stringer  16  causing the wall  60  to penetrate more deeply into the stair stringer  16 . Further, the present invention provides that a strip of bituminous barrier strip be installed at this location to further enhance the seal and prevent the migration of water.  
         [0037]    The bottom surface  58  of the stair stringer support member  30  includes holes therein to receive mounting members  66  to facilitate the stair stringer support  30  interface with the adjacent ground  20 . The mounting members  66  may be concrete hook anchors that are cast into a concrete pad when formed, concrete sleeve anchors that are drilled into concrete after it is cured, leveling bolts threadedly received into said bottom surface of said stair stringer support  30  or flange connections for attaching to additional wood supports such as another deck level.  
         [0038]    It can therefore be seen that the present invention provides a novel integrated system for constructing a rot resistant wood framed structure that provides superior water sealing properties and a novel construction for preventing water from migrating into the critical joints of the wood structural members. Further, the present invention can be modified to accommodate any conceivable number of different wood framed structures to create a highly improved and durable structure. For these reasons, the present invention is believed to represent a significant advancement in the art, which has substantial commercial merit.  
         [0039]    While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.