Abstract:
A crawlspace encapsulation system that enables sealing and insulating of the crawlspace while allowing for the venting of gases trapped between the ground and the sealing and insulating system. The crawlspace encapsulation system includes an insulation joist plug, one or more insulation panels, and a polymeric membrane.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the earlier filing date of provisional application 61/353,681, filed Jun. 11, 2010. 
    
    
     FIELD 
     The present disclosure relates to an insulated foundation and subflooring structure. More particularly, the disclosure relates to an insulation structure having improved insulating and venting structure. 
     BACKGROUND 
     Many homes are constructed having a crawlspace that is created under the floor of the house as a result of the house being placed on a foundation. Crawlspaces are generally porous and do not provide adequate sealing against moisture and insulating to prevent heat loss and gain. When moisture enters the crawlspace, water enters the wood forming the floor joists and the various other flooring structures above the crawlspace. The moisture can result in a large number of mold spores and create a desirable environment for insects to live. An additional problem relates to preventing insects such as termites from nesting in the crawlspace. Another problem relates to allowing the ventilation of gases, such as radon, while still providing protection against moisture and heat loss and gain. While various attempts have been made to provide suitable sealing and insulating systems, improvement is desired. 
     Accordingly, the present disclosure relates to an encapsulation system that provides for sealing against moisture, insulating to prevent heat loss and gain, the repelling of insects, and allowing the venting of gases in crawlspaces. 
     SUMMARY 
     In a first aspect, the present disclosure provides an insulated foundation and subflooring structure that includes a foundation wall, a sill plate fastened to the top of the foundation wall, a header joist fastened to the top of the sill plate, a first and a second floor joist spaced apart from each other where the floor joists are fastened to the top of the sill plate, and an insulating joist plug compressibly fit between the floor joists and fastened to the top of the sill plate. 
     In one embodiment, the insulated foundation and subflooring structure includes an insulating joist plug made from a foamed polymer selected from the group consisting of polystyrene, polyurethane, polyethylene, polypropylene, polyisocyanurate, and mixtures thereof. In certain embodiments of the insulated foundation, the insulating joist plug is made of foamed polystyrene. 
     In certain embodiments of the insulated foundation and subflooring structure, the insulating joist plug is made of a foam polymer having an insecticide dispersed within the foamed polymer. Further, in some embodiments according to the present disclosure, the insulating joist plug is made of a foamed polymer having an insecticide, containing a boron-containing compound, dispersed within the foamed polymer. In one embodiment of the insulated foundation, the boron-containing compound is disodium octaborate tetrahydrate. 
     In certain embodiments of the foundation and subflooring structure, the insulating joist plug has an R value from about 10 to about 36. Further, in some instances, the insulating joist plug contains one or more slits. The insulated foundation and subflooring structure may also consist of the two floor joists where the two floor joists are substantially parallel to one another and perpendicular to the header joist. 
     In a second aspect, the present disclosure provides a crawlspace encapsulation system that includes a foundation wall, a sill plate fastened to the top of the foundation wall, a header joist fastened to the top of the sill plate, a first and second floor joist space apart from each other where the floor joists are fastened to the top of the sill plate, an insulating joist plug shaped to compressibly fit between the floor joists, one or more insulating panels fastened to a portion of the foundation wall, and a polymeric membrane that overlaps a portion of the insulating panels and covers the ground adjacent the foundation wall. The polymeric membrane is preferably waterproof and/or resistant to moisture and/or other vapors. 
     In one embodiment, the encapsulation system includes the insulating panels having a portion that is comprised of one or more venting channels that are connected to the space beneath the polymeric membrane. 
     In certain embodiments of the encapsulation system, the insulating joist plug and insulating panels are made of a foamed polymer selected from the group consisting of polystyrene, polyurethane, polyethylene, polypropylene, polyisocyanurate, and mixtures thereof. In a particular embodiment, the insulating joist plug and the insulating panels are made from foamed polystyrene. 
     In certain embodiments, the encapsulation system includes an insulating joist plug and insulating panels made of a foam polymer having an insecticide dispersed within the foamed polymer. In one embodiment, the insulating joist plug and insulating panels are made of a foamed polymer having an insecticide, containing a boron-containing compound, dispersed within the foamed polymer. In a particular embodiment, the boron-containing compound includes disodium octaborate tetrahydrate. 
     In certain embodiments, the floor joists are substantially parallel to one another and are substantially perpendicular to the header joist. 
     The encapsulation system preferably has an insulating joist plug with an R value from about 10 to about 36 and insulating panels with an R value from about 5 to about 30. The encapsulation system also preferably is configured such that at least a portion of the insulating panels are separated from one another on one side of the insulating panels. Preferably, the insulating panels have a width of from about 1 to about 24 inches and are fastened to one another by adhesive tape or a polymeric film. 
     In certain embodiments of the encapsulation system a portion of the insulating panels may be removed to provide access to the foundation wall and sill plate. In one particular embodiment, a portion of the insulating panels includes a hinge that allows the portion to be opened to provide access to the foundation wall and sill plate. In one embodiment, the insulating joist plug may be removed from the encapsulation system to provide access to the foundation wall and the sill plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages of the disclosure are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
         FIG. 1  is a perspective view of an insulating joist plug according to one embodiment of the disclosure. 
         FIG. 2  is a top plan view of the insulating joist plug of  FIG. 1 . 
         FIG. 3  is a side view of an encapsulation system according to one embodiment of the disclosure. 
         FIG. 4  is a top plan view of the insulating panels having venting channels adjacent the foundation wall according to one embodiment of the disclosure. 
         FIG. 5  is a top plan view of an alternate embodiment of an insulating panel having individual panels of varying thickness to create venting channels according to one embodiment of the disclosure. 
         FIG. 6  is a side view of the insulating panel of  FIG. 4  showing the hinged portion of the panel providing access to the foundation wall and sill plate according to one embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the drawings, the disclosure relates to a crawlspace encapsulation system  10  having one or more insulating joist plugs  12  installed above one or more insulating panels  14  and a polymeric ground membrane  16  installed on the floor of the crawlspace. 
     In a typical foundation and subflooring system, as shown in  FIG. 3  for example, the floor  114  is supported by one or more floor joists  100  rest on top of the sill plate  104  and are fastened to a header joist  102  also resting on the sill plate  104 . The sill plate  104  is attached to the top of the foundation wall  106 . The foundation wall  106  supports the sill plate  104  and flooring joists  100  and is attached to the ground  110 . The foundation wall  106  may include a ventilation duct  112  between the interior and exterior of the crawlspace. Any or all of the floor joists  100 , header joist  102 , sill plate  104 , and foundation wall  106  may be chemically treated to provide resistance to termite infestation. For instance, a composition comprising a boron-containing compound (such as disodium octaborate tetrahydrate) and a glycol and/or glycerine may be applied to the outer surfaces of these members. 
     With reference to  FIG. 2 , the insulating joist plug  12  is desirably configured to compressibly fit between the floor joists  100   a  and  100   b . The insulating joist plug  12  is constructed of a foamed polymer such as polystyrene, polyurethane, polyethylene, polypropylene, polyisocyanurate, and like materials. More preferably, the foamed polymer is foamed polystyrene. It is also understood that the insulating joist plug  12  may be constructed of a foamed polymer which includes an insecticide dispersed in the interstitial spaces between the cells or beads of the foamed polymer. For instance, an organic insecticide such as deltamethrin or imidicloprid may be included within the foamed polymer. More preferably, the insecticide may be a boron-containing compound, such as disodium octaborate tetrahydrate. Other suitable boron-containing insecticide compounds include boric acid, sodium borates (such as borax and sodium pentaborate) calcium borates, sodium calcium borates, and mixtures thereof. Certain insects, such as termites, may forage on and damage untreated foamed polymers, or eat wood. The inclusion of such insecticides within the insulating joist plug provides the joist plug with a resistance to termite foraging and damage. 
     The insulating joist plug preferably includes a plurality of slits  14  oriented parallel to the floor joists. The slits  14  allow for compression of the insulating joist plug  12  to ensure a tight fit of the insulating joist plug  12  between the floor joists  100   a  and  100   b . Because of the compression abilities of the insulating joist plug  12 , the width W ( FIG. 1 ) of the insulating joist plug  12  may be such that it is equal to or slightly greater than the distance between floor joists D, ensuring a secure fitting of the insulating joist plug  12 . In typical modern framing, floor joists are generally placed about 16 inches apart from center to center. Allowing for the thicknesses of the floor joists, this means that the width W of the insulating joist plug will generally be from about 14″ to about 15″ inches. 
     The insulating joist plug  12  is preferably configured to rest above of the sill plate  104  and to sit adjacent to the header joist  102 . The insulating joist plug generally has a thickness from about 2½″ to about 10″ inches and provides an insulating R value of from about 10 to about 36. 
     The encapsulation system  10  also includes a plurality of insulating panels  14 . The insulating panels  14  may be formed from the same polymeric materials as the insulating joist plugs  12 , although the thickness and other dimensions of the panels  14  may differ from those of the joist plugs  12 . For instance the insulating panels  14  may be constructed of a foam polymer such as polystyrene, polyurethane, polyethylene, polyproplyene, polyisocyanurate, and like materials. More preferably, the foamed polymer is foamed polystyrene. The insulating panels  14  may also include an insecticide as in the insulating joist plug  12 . Preferred insecticides include boron-based compounds such as disodium octaborate tetrahydrate. The insulating panels generally provide an insulating R value of from about 5 to about 30. 
     In one embodiment, shown in  FIG. 4 , the insulating panels  14  may be configured such that alternating rectangular insulated panels  400  and one or more vented insulating panels  402  are placed adjacent to each other. The vented insulating panels  402  preferably include a vent channel  404  that is oriented such that the open side of the vent channel is directly adjacent to the foundation wall  106 . The vent  404  is also preferably oriented such that it traverses the vertical length of the insulating panel  402  from the bottom of the insulating panel  402  to the top of the insulating panel  402  near the floor joist  100  and such that the vent  404  comes in contact with the ventilation duct  112  of the foundation wall  106 . The insulating panels  14  may be configured for installation individually or such that the insulating panels  14  are attached to one another by an adhesive tape or polymeric film attached on one side of the insulating panels  14 . Attachment of the insulating panels  14  to one another by an adhesive tape or polymeric film allows the insulating panels  14  to fold so that they may be placed into the crawlspace for installation. 
     In an alternative embodiment, shown in  FIG. 5 , the insulating panels  14  may also be configured such that an alternating panel  502  is of a different thickness than the adjacent insulating panel  504 . The insulating panels with a lesser thickness  504  than the adjacent panels  502  create a vent channel  506  directly adjacent to the foundation wall  106 . 
     With reference to  FIG. 6 , the insulating panels  14  may include a removable panel  602  located at the top of the insulating panel  14 . The removable panel  602  is preferably configured to allow access to the foundation wall  106  and the sill plate  104 . The removable panel  602  preferably rests on top of the lower portion of the insulating panel  604  and may be configured to be completely removed during inspection and repair of the foundation wall  106 . The removable panel  602  may then be reinstalled upon completion of inspection and repair. It is also understood that the removable panel  602  may be attached to the lower portion of the insulating panel  604  through use of an adhesive tape, polymeric film,  606  or similar means, allowing the removable panel  602  to hinge with respect to the lower portion of the insulating panel  604 . 
     In a particularly preferred embodiment, the insulating panel  14  may be provided as a panel having a width of approximately eight feet and a height of approximately four feet. Both surfaces of the panel  14  are preferably laminated with a polymer film, such as a polyethylene film. Before being laminated, however, the panel  14  is preferably scored across its width at approximately one foot intervals. The panel  14  may then be easily cut along one of the score lines to remove a portion of the panel so as to provide an appropriate size for a particular crawlspace installation. Alternatively, the panel may be cut along one of the score lines, while leaving the laminated film intact, thereby providing a hinge. In this way a portion of the panel  14  may also be temporarily folded back along one of the score lines to facilitate inspection of the foundation hidden behind the panel. 
     With reference to  FIG. 3 , the polymeric membrane  108  may preferably be installed on the ground of the crawlspace adjacent the foundation wall  106 . The polymeric membrane  108  may be fastened to the insulating panels  14  on the second side facing the crawlspace such that the polymeric membrane overlaps at least a portion of the insulating panels  14  forming a substantially airtight seal. The overlap and seal of the polymeric membrane  108  over the insulating panels  14  ensures that no moisture or other gas will be allowed to pass from the ground to the crawlspace 
     The polymeric membrane is preferably composed of a polymer such as polyethylene or polypropylene, and generally has a thickness from about 1 to about 5 mils. The polymeric membrane acts as a barrier to undesired vapors, such as water vapor and radon. In some instances, the polymeric membrane may also be waterproof. 
     The crawlspace encapsulation system creates a waterproof barrier between the crawlspace and the ground. When gases (such as radon gas) and moisture rise from the ground, the gases and moisture may occupy the space between the polymeric membrane  108  and the ground  110 . The polymeric membrane  108  prevents the moisture and gases from entering the crawlspace and allows the gases and moisture to travel to the insulating panels  14  and enter the vent channel  404 . The moisture and gases then travel through the vent channel to a ventilation duct  112  in the foundation wall  106  where it passes outside. 
     According to the present disclosure, the insulating joist plug preferably has with an R value from about 10 to about 36. The insulating panels preferably have an R value from about 5 to about 30, and more preferably from about 10 to about 15. 
     The foregoing description of preferred embodiments for this disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated.