Abstract:
Growth of toxic molds in residential and commercial buildings is prevented or eradicated by installing a system including liquid spray nozzle units within interior walls spaces likely to accumulate moisture. Spray nozzles are mounted in spaces between column or stud members of interior walls, plumbing chases, or similar locations and may be manifolded and connected to a fitting projecting through a wall in an inconspicuous location for connection to a portable pump unit for spraying surfaces of structural elements adjacent the spray nozzles. Methods for treating building interiors include applying a spray of anti-microbial treatment fluid to interior facing surfaces of exterior walls, plumbing chases, interior bathroom and kitchen wall column members and floor plates, floors, such as concrete slabs or wood flooring surfaces, roof penetrations and subfloors for utility appliances.

Description:
BACKGROUND  
         [0001]    Growth of fungi, such as certain types of black or gray molds in residential and commercial buildings, can produce significant health hazards to human occupants of such buildings. For example, the black molds known as Stachybotrys and Memnoniella are types that are known to produce mycotoxins which are hazardous to human health when exposure is encountered. These mold types typically occur on repeatedly wetted materials that contain cellulose, for example, including interior wall paneling, such as gypsumboard, and other materials used in residential and commercial buildings including cardboard, ceiling tiles, cellulose insulation, wood, etc.  
           [0002]    There are several sources of moisture which can accelerate and promote the growth of gray and black molds including the types mentioned above. Water piping extending through plumbing chases and piping extending through voids or spaces in interior walls of residential and commercial buildings can produce minute leaks sufficient to wet adjacent materials and promote the growth of mold. Leakage from the exterior of a building into various parts of the building, which goes undetected, can also wet the surfaces of various materials which will promote the growth of toxic molds. Still further, condensation, from time to time, on the surfaces of plumbing piping, air conditioning ducts, refrigerant conduits and other structures is also a source of moisture which can result in the growth of molds in unseen spaces, such as the interior wall spaces of buildings, among other locations, all of which are a source of mold contamination and exposure to humans.  
           [0003]    The growth of mold in interior wall spaces in residential and commercial buildings is particularly difficult to detect and difficult to eradicate by conventional methods. Since the interior wall spaces have been covered with various types of wall paneling, the growth of mold goes undetected and, when detected, is difficult to treat without major renovation of the building. Accordingly, there has been a longstanding need for the development of mold and other pest prevention systems and treatment methods which can eliminate toxic molds, in particular, from various places within a residential or commercial building, including interior wall spaces, plumbing chases, and virtually any portion of a building structural feature which is likely to be exposed to moisture, repeatedly, during the life of the building. It is to these ends that the system and methods of the present invention have been developed.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention provides a system and methods for preventing or eliminating fungi, such as gray or black mold, from various surfaces of a residential and/or commercial building including interior wall spaces, plumbing chases and other portions of a building structure which are likely to serve as a place for growth of such mold.  
           [0005]    In accordance with one aspect of the present invention, a mold prevention or eradication method is provided which includes the steps of removing all construction debris interfering with the application of a chemical mold treatment substance, such as an anti-microbial liquid, during construction, remodeling or repair of a building interior. The method includes spray application of a suitable anti-microbial fluid by delivery of a spray of a predetermined liquid particle size to surfaces which are likely to allow growth of mold thereon. A method in accordance with the invention may include that of applying the anti-microbial treatment fluid to all exposed interior surfaces of exterior walls of the building or structure, which may be done prior to installing interior wall panels or coverings at said exterior walls. The method also may include applying the treatment fluid, such as an anti-microbial liquid, to all plumbing chases and interior walls in rooms which include plumbing piping, such as bathrooms, kitchens, and the like. The treatment method preferably further includes applying the treatment fluid to wall column members, or so-called studs, floor plates, the interior surfaces of wallboard or paneling and other structural features which include cellulose or other mold growth promotion materials as part of the composition of the structural member. Still further, the treatment method involves application of a spray of the treatment fluid to the perimeter of the building flooring, a predetermined distance in from an exterior wall, including treatment of second and third story subflooring and decking, and treatment at or in the vicinity of all roof penetrations of the building.  
           [0006]    A method in accordance with the invention also may be carried out by a system in accordance with the invention as will be explained in detail herein.  
           [0007]    In accordance with another aspect of the present invention, a mold prevention and treatment system is provided which may be installed in various locations which are susceptible to the growth or harboring of toxic molds and vermin, including the spaces between interior wall panels, which spaces include plumbing or other sources of water leakage or condensation. The mold prevention and treatment system preferably includes a single or multi orifice liquid spray delivery system which is preinstalled and supported between opposed panels of an interior wall structure, for example. The delivery system also preferably includes a coupling or connector disposed in a location normally hidden from view so that, from time to time, a source of pressurized anti-microbial treatment fluid may be connected to the delivery system for spraying the spaces which are susceptible to mold growth or other contamination.  
           [0008]    The system may be installed in new construction or during major repair or renovation of a structure at which the eradication of mold is desired or has been required. Moreover, the system comprises one or more spray nozzles which are operable to emit a fine mist of an anti-microbial treatment fluid, preferably in liquid form, in the vicinity of likely locations for mold growth to prevent or eliminate such growth. The system provides access to likely locations of mold growth or other contamination which are hidden from view by the occupants of the building and are normally inaccessible unless major structural modifications are made to the building.  
           [0009]    Those skilled in the art will further appreciate the advantages and superior features of the system and methods of the present invention together with other important aspects thereof upon reading the detailed description which follows in conjunction with the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective view of a residential dwelling unit or house, with the roof structure removed, to illustrate typical locations for a prevention and treatment system in accordance with the invention;  
         [0011]    [0011]FIG. 2 is a detail elevation view taken generally from the line  2 - 2  of FIG. 1;  
         [0012]    [0012]FIG. 3 is a view taken substantially from the line  3 - 3  of FIG. 2; and  
         [0013]    [0013]FIG. 4 is a view taken generally from the line  4 - 4  of FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    In the description which follows, like elements are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale and some elements may be shown in somewhat generalized or schematic form in the interest of clarity and conciseness.  
         [0015]    The mold prevention and treatment system and methods of the invention may be carried out in conjunction with many types of residential dwelling units, commercial buildings, or virtually any structure which may be occupied by humans and which may be susceptible to contamination, including the growth of mold of the types discussed herein. By way of example only, FIG. 1 illustrates, in perspective view, the interior of a residential dwelling unit or house  10  which includes exterior walls  12 ,  14 ,  16 ,  18 ,  20 , and  22  enclosing a dwelling unit having several rooms, as illustrated. The dwelling unit  10  may be built on a concrete slab type foundation  24  or one of many other types of foundations commonly used for residential or commercial structures. The interior of dwelling unit  10  is subdivided by plural interior walls, certain ones of which are identified herein by numerals  26 ,  28 ,  30 ,  31 ,  39  and  39   a  by way of example only, and which contribute to dividing the interior of the dwelling unit into plural rooms such as a kitchen  32 , first and second bathrooms  34  and  36 , an air conditioning unit closet  38  and a water heater closet  40 , for example, see FIGS. 2 and 3, also. Each of the aforementioned rooms has plumbing piping leading thereto and disposed within certain interior walls, such as the wall  26  for example. Each of the piping locations within interior walls may be subject to leakage or condensation on the exterior surfaces of the piping and which can wet the surfaces of the adjacent walls and/or floors.  
         [0016]    Referring to FIGS. 2 and 3, by way of example, there is illustrated a portion of interior wall  26  extending between a floor surface  24   a  and a ceiling structure including paneling  25 . Interior wall  26  is of somewhat conventional construction including spaced apart vertical column members  42 , commonly known as studs, which are typically formed of wood, such as pine. Column members or studs  42  are secured to an elongated wood floor plate member  44  and to a ceiling plate or joist member  46  and form plural spaces  48  therebetween and between wall paneling members  50  and  52 . In FIG. 2 a portion of wall panel  50  is broken away to show the spaces  48  separated by the column members  42 . Since interior wall  26  forms one wall of bathroom  34 , for example, there exist certain pressure water conduits  54   a ,  54   b , and  54   c  extending therewithin and leading to certain fixtures, not shown, within bathroom  34 . Additionally, certain kitchen fixtures, not shown, may include one or more water conduits or lines leading thereto, which water lines may also extend within one or more of the spaces  48 .  
         [0017]    The spaces  48  are susceptible to moisture which may originate from a minute leak in one or more of the pressurized water lines  54   a ,  54   b , or  54   c . Moisture may also condense on one or more of these water lines if the condition of ambient atmospheric air within the dwelling unit  10  and the temperature of the water flowing through one or more of the water lines is conducive to such condensation. The materials of which the wall paneling  50  and  52  and the structural members  42  and  44  are formed often contain cellulose on which certain types of mold, as described previously herein, will grow profusely.  
         [0018]    A method in accordance with the present invention for treatment of the building or dwelling unit  10  may be carried out during or upon substantial completion of construction or major remodeling of the building. Such method will be described in further detail hereinbelow. However, one aspect of the invention provides a system for mold eradication and prevention, which system may also be installed during new construction or major remodeling of the building  10 , for example.  
         [0019]    At least one part of a mold prevention system of the invention is illustrated by way of example in FIGS. 2 and 3, and is generally designated by numeral  45 . Mold prevention system  45  includes one or more spray nozzles  58  formed integral with or suitably secured to T-type fittings  60  which are manifolded together by a set of conduit sections  62 ,  63  and  64 , for example. The manifold formed by the conduit sections  62 ,  63  and  64  and the fittings  60  may be installed during new construction of the dwelling unit  10  or during remodeling or renovation. The manifolded spray nozzles  58  are connected at one end of conduit  64  to a further conduit section  66  via an elbow fitting  65  extending to a fitting  68  which may have a connector end  70  extending through wall panel  50  and disposed in a hidden location, such as within a cabinet or enclosure  74 , FIG. 3. The endmost fitting  60  is closed by a suitable plug  61 , FIG. 2.  
         [0020]    The system  45 , comprising the manifolded spray nozzle arrangement illustrated in FIGS. 2 and 3, may be connected, from time to time, to a source of fungicide including a portable electric motor driven pump unit generally designated by the numeral  75  in FIG. 2. The pump unit  75  includes a suitable electric motor  76  drivingly connected to a centrifugal, high pressure pump  78  operable to deliver liquid fungicide to the manifolded spray nozzles  58  at a pressure of up to about 200 psig. The pump unit  75  is adapted to be connected to a source of fungicide including a portable reservoir  80  having a quantity of liquid pesticide or fungicide  82  therein and which may be of a type commercially available and known to be suitable for a eradicating mold of the types described herein or other vermin which may require eradication from time to time. Flexible conduits  83  and  85 , FIG. 2, interconnect pump  78  with reservoir  80  and pump  78  with a suitable quick disconnect fitting  87  which may be releasably connected to fitting  68  at connector end  70 .  
         [0021]    Accordingly, the mold prevention and treatment system  45  shown in FIGS. 2 and 3 or a modified form thereof may be installed in any one of the interior walls of the dwelling unit  10  which include water piping, or are likely to be exposed to moisture. In this way, the dwelling unit  10  may be treated, from time to time, on a maintenance basis to eradicate or prevent the accumulation of toxic molds within the wall spaces enclosed by the interior walls, including the interior walls  26  and  28 .  
         [0022]    For example, referring briefly to FIG. 4, an interior wall  31  separates the air conditioning unit closet  38  from the water heater closet  40 . As shown in FIG. 4, the closet  38  includes a conventional forced air heating and air conditioning unit  90  mounted on a suitable subfloor  92  and enclosed by walls  28  and  31 , as well as interior wall  39  and an interior wall  39   a , FIG. 1. In like manner, water heater closet  40  is adapted to be provided with a conventional water heater  93  mounted on a subfloor  94 , which may be an extension of subfloor  92 , as shown. Pressure water lines  95  and  96  extend partly within a space  33  within interior wall  31 . Space  33  also includes one or more spray nozzles  58  mounted therein and operably connected to a fitting, such as the fitting  68 , not shown in FIG. 4. Still further, one or more manifolded spray nozzles  58  are disposed in interior wall space  37  formed within interior wall  28 , also as shown in FIG. 4, for discharging fungicide into the space  37  to prevent or eradicate mold which might grow within the space as a consequence of leakage from or condensation on pressure water line  97 .  
         [0023]    It will be noted that FIG. 4 also illustrates a penetration  69  through a roof deck  71  for a vent pipe  98  for water heater  93  which should also be treated for mold prevention or eradication in accordance with a method of the present invention.  
         [0024]    Accordingly, with various single or plural manifolded spray nozzles  58  disposed within interior walls of the dwelling unit  10  and connected to suitable fittings  68  at various hidden locations throughout the dwelling unit, as illustrated by way of example in FIGS. 2 and 3, the portable pump unit  75  and reservoir  80  may be carried from one location to another within the dwelling unit, periodically, suitably connected to respective fittings  68  and energized so that a quantity of mold eradicating anti-microbial fluid, preferably in liquid form, may be discharged into the spaces likely to provide for growth of mold, for example. In this way, the dwelling unit  10  may be prevented from acquiring growth of toxic mold or the like. Those skilled in the art will also recognize that the system and methods of the invention may be carried out using other anti-microbial treatment fluids, including fungicide or pesticide-type fluids, to rid or eradicate contaminations of various types other than molds of the types described herein.  
         [0025]    The installation of the nozzles  58 , their associated fittings  60  and  68  and connecting piping may be carried out during construction of a building, such as the dwelling  10 , or during major remodeling or, as required after initial construction has been completed.  
         [0026]    One method in accordance with the present invention contemplates that mold prevention and eradication within a building such as the dwelling unit  10 , may be carried out as described hereinbelow.  
         [0027]    During construction of a building, such as the dwelling unit  10 , a requisite number of spray nozzles  58  and associated fittings and conduits are installed, generally as described above and as shown in the drawing figures. A typical spray nozzle or misting nozzle  58  may be of a type commercially available, have a 0.008 inch diameter orifice mounted in a stainless steel T-fitting  60  with 0.375 inch internally threaded national pipe thread construction. The fittings  60  may be connected to 0.375 inch diameter high pressure polyethylene tubing used for the conduit sections  62 ,  63 ,  64  and  66 , for example, with each fitting  60  being disposed in a void or space, such as the spaces  48 . One source of spray nozzle commercially available is of a type used for water misting systems for horticultural or human comfort purposes in out of doors facilities. Equipment available from Arizona Mist of Gilbert Ariz. may be suitable for the system  45  described and shown. As previously mentioned, systems in accordance with the invention and, as shown in FIGS. 2 and 3, may be installed during new construction or during remodeling or rehabilitation of a building. Suitable notches or holes  42   a , FIG. 2, may be formed in the column or stud members  42  for extending the conduits  62 ,  63  and  64  therethrough, for example. The manifolded spray nozzles  58  of system  45  are advantageously supported by the column members  42  within the spaces  48 .  
         [0028]    After installation of the system  45 , for example, and upon completion of construction, the spaces  48  may be treated at any time that mold growth may occur or be anticipated. Moreover, during construction or remodeling of a building, such as the dwelling unit  10 , a method in accordance with the present invention also contemplates the steps of cleanup of all construction debris which might interfere with the application of fungicide to be sprayed on a surface, such as the column members  42 , the floor plate  44 , the floor surface  24   a , the interior wall panels such as the panels  50  and  52  and the wall panels which form the interior walls  28  and  31 . All debris collected by sweeping, picking up or vacuuming the surfaces in question should, of course, be subjected to suitable disposal. Once the interior structural features of the dwelling unit are cleaned, a portable application unit including components such as the pump unit  75  and reservoir  80 , may be brought to the dwelling unit and connected to a suitable portable high pressure spray nozzle, not shown, which may be manually operated.  
         [0029]    All surfaces which are subject to mold growth should then be sprayed, including all wood and other structural features which include cellulose material, as well as concrete surfaces. For example, the subfloors  92  and  94  should be treated and the point of penetration  69  of the vent conduit  98  at the roof  71  should be sprayed. The treatment fluid is applied via the aforementioned equipment so that a predetermined fungicide particle size of from about eighteen to one hundred microns may be sprayed on the surfaces.  
         [0030]    In addition to treating the exposed interior surfaces mentioned above, the interior surfaces of exterior walls  12 ,  14 ,  16 ,  18 ,  20  and  22  should be treated. In addition, any space which occupies water piping or structural features which are subject to accumulation of leaking water or condensed water vapor should be sprayed during the mold prevention or eradication treatment process. As described in detail above, all interior wall structural components, such as studs or columns, floor plates, and the interior of wall paneling should be sprayed as well as subfloors which support equipment which is likely to leak water or to shed condensed water vapor. Still further, the perimeter of all floors from the outer edge thereof to at least about two feet toward the interior of the structure should be sprayed with fungicide prior to the application of floor coverings. As shown in FIG. 1, the floor surface  24   a  should be treated inward from the exterior walls  12 ,  14 ,  16 ,  18 ,  20 , and  22  a distance of up to about two feet as indicated by the treatment lines  12   a  and  14   a  in FIG. 1, for example.  
         [0031]    The above-described methods and system are exemplary. Various residential dwelling structures and commercial buildings will have other structural features which will advantageously utilize the treatment system and methods in accordance with the invention. For example, in many multi-story buildings or buildings with basements, the interior floors may be other than concrete slabs and be built up of spaced apart structural members with subflooring disposed thereover and paneling disposed thereunder. The interior spaces formed by such flooring structures are also susceptible, in many instances, to mold growth and should have installed therein a system as described hereinabove and shown by way of example in FIGS. 2 and 3.  
         [0032]    Although preferred embodiments of a system and methods for mold prevention and eradication have been described in detailed herein, those skilled in the art will also recognize that various substitutions and modifications may be made without departing from the scope and spirit of the appended claims.