Patent Publication Number: US-2007113499-A1

Title: House wrap with integral furring strips

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to exterior walls of building structures, primarily residential structures, wherein specific measures have been taken to ensure that the wall area between the exterior siding and the sheathing therebeneath can be dry and free of water buildup.  
      We are all aware of the damage that water penetration can cause including structural rotting, mildew formation, mold or mold spores may penetrate into the interior of a structure and can cause adverse health consequences for the occupants.  
     SUMMARY OF THE INVENTION  
      The present invention relates to a method and apparatus for ensuring that water entrapped between a structure&#39;s sheathing and its exterior cladding or siding is eliminated by means of drainage and drying of the area therebetween. This is accomplished through the use of a conventional water resistive barrier (WRB—also sometimes referred to as “Housewrap”) with furring strips attached to at least one side of the WRB. By using a furring strip on each side of the WRB, the distance between the sheathing and the siding or cladding is doubled to approximately 6-8 mm. The furring strips are placed approximately eight inches apart with the passages extending parallel to their vertical orientation, thus promoting draining and drying which helps prevent the accumulation of water between the sheathing and cladding.  
     DISCUSSION OF KNOWN PRIOR ART  
      A recent search of the Patent Office files in the appropriate Class and subclasses revealed the following prior art: 
      U.S. Pat. No. 6,938,383—issued to Richard J. Morris et al on Sep. 6, 2005—discloses a vented furring strip that is used to ventilate the area between the sheathing of a residence and the exterior siding or cladding and eliminate any moisture or water from therebetween. The elongate furring strips are installed as separate pieces on the first layer of a wall and covered with an exterior siding. The furring strips space the siding apart from the sheathing, forming a plurality of enclosed cavities or air spaces. The cavities are in fluid communication with each other through air passages in the furring strips that extend transversely to a longitudinal axis of the furring strip, i.e. these passages through the furring strips are horizontally disposed and serve to connect the cavities that are formed between adjacent furring strips thus providing ventilation of the entire area. By allowing air to enter the cavities between adjacent furring strips, there is a total or complete ventilation of the area between the sheathing and the exterior siding, thus the problems associated with water and moisture such mildew, rotting, mold and mold spores becomes moot.     U.S. Pat. No. 6,357,193—issued to Richard J. Morris on Mar. 19, 2002—discloses a roof batten for use in spacing tiles or similar exterior roofing members from a roof overlayment. This “batten” is structurally the same as the “furring strips” referred to in Morris, &#39;383 immediately above.     U.S. Pat. No. 6,267,668—issued to Richard J. Morris on Jul. 31, 2001—discloses a roof vent formed by utilizing a pair of spaced ventilation devices  50  that are advantageously disposed between installed sheets  20  and ridge cap  22  to insure that air exchange proximate peak  14  between the interior and exterior of roof will occur within vent  50 .    

      Although these three references discloses ventilated furring strips, batten strips, and ridge vent spacer strips they each rely on cavities that are within the strips that are transverse to the longitudinal axis of the various strips. Further, these three patents are all directed to the use of furring strips installed individually in the field whereas the subject matter of the instant invention provides a series of furring strips that are pre-attached to at least one side of conventional water resistive barrier (WRB) in the factory and automatically spaced and installed when the WRB is installed in the field. Additionally, the instant invention provides air passages or ridges that extend along the longitudinal axis, vertically disposed, which helps to promote drainage and drying longitudinally and prevents water from migrating laterally between the furring strips.  
     OBJECTS OF THE INVENTION  
      An object of the invention is to provide a water resistive barrier (WRB) with furring strips for draining and drying the area between the exterior sheathing and the exterior cladding or siding.  
      Another object of the invention is to provide a WRB with furring strips that have been previously attached to the WRB, which facilitates placement and spacing of the furring strips at the same time the WRB is installed.  
      A further object of the invention is to attach the furring strips to any type of WRB, such as commercially available housewraps, regardless of the material composition of the WRB or furring strip.  
      Yet another object of the invention is to provide a house wrap that includes furring strips that will help ensure that water will not accumulate between the structure&#39;s sheathing and the WRB or the WRB and the exterior cladding.  
      A further object of the invention is to provide vertical passageways or ridges to help promote drainage and drying longitudinally in the wall assembly.  
      These and other objects of the invention will become more apparent hereinafter. The instant invention will now be described with reference to the accompanying drawings wherein like reference characters designate the corresponding parts throughout the several views. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an illustration of a house wherein the furring strips have been attached to the water resistive barrier (WRB) prior to installation of the WRB on the house.  
       FIG. 2  is a view of a roll of WRB with the furring strips attached to both sides thereof prior to installation on the building.  
       FIG. 3  is a sectional view taken along the plane  3 - 3  of  FIG. 2  illustrating the furring strips and their placement on the inner and outer surfaces of the WRB material.  
       FIG. 4  is a sectional view taken along the plane  44  of  FIG. 1  illustrating the passages within a pair of furring strips on opposite sides of the WRB.  
       FIG. 5  is a detail illustration of the area enclosed by the oval in  FIG. 4 , illustrating the vertical passage in the furring strips.  
       FIG. 6  is a sectional view taken along the plane  6 - 6  of  FIG. 4 , illustrating the relationship of the furring strips relative to the WRB and the exterior siding. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
      Referring now to  FIG. 1 , there is shown a house with an attached garage  51 . As illustrated, house  50  is wrapped with a water resistive barrier  60 , which will be referred to as WRB hereinafter, that includes a plurality of furring strips  61  attached to both sides of WRB  60 . However, only the outer side is shown in this view with the furring strips  61  aligned as successive rows of WRB  60  are applied to the house  50 . As noted in  FIG. 1 , the lowermost horizontal row of WRB  60  begins at the lowermost right-hand side of house  50  with furring strip  61  aligned with the right end of the exterior sheathing and flap portion  60 RF extending around the house on the right side thereof. Additionally, the lower end  61 B of furring strips  61  are aligned with the bottom of the exterior sheathing, not shown. The next horizontal row of WRB  60  is installed by overlapping the bottom of the roll  60 BF over the top flap  60 TF of the roll and unwrapping the WRB from the roll  60 , thus any water from the upper row of WRB  60  is discharged onto the top flap  60 TF of the previous roll for easy run-off down the building side.  
      Turning now to  FIG. 2 , there is shown a roll of WRB  60  with furring strips  61  attached to both sides thereof. As shown, roll  60  is partially unwrapped showing a right flap portion  60 RF at the rightmost end of roll  60 , the opposite end is provided with a left flap portion  60 LF, not shown. Furring strips  61  are positioned on both sides of the WRB with the sides offset vertically from each other, leaving a top flap portion  60 TF and a bottom flap portion  60 BF on the respective sides thereof. This feature facilitates proper overlapping of rolls  61  as shown in  FIG. 1 . Although emphasis has been placed on the use of the WRB in “roll form”, it has been found to be equally useful when presented in “folded sheet form”.  
      Referring now to  FIG. 3 , there is shown a sectional view taken along the plane  3 - 3  of  FIG. 2 . This sectional view illustrates the relationship between the furring strips  61 W and  61 N. As shown, the larger strip  61 W is approximately  1  and ¾ inches wide while the other, narrower strip  61 N is approximately 1¼ inch in width. The narrower strip  61 N is placed against the sheathing of the home with the wider strip  61 W in abutting relation to the siding. Narrow strip  61 N is approximately 1¼ inch in width, centered on the wider strip  61 W with approximately ¼ overlap on each side thereof. As shown, WRB  60  is sandwiched between the two furring strips  61 W and  61 N. The WRB  61  is installed with the narrower furring strip  61 N against the sheathing. The reason for installing the furring strips in this manner is to minimize surface contact and thereby reduce the potential for water retention against the underlying structure.  
      Turning now to  FIG. 3 , there is shown the wider furring strip  61 W on one side of WRB  60  with narrower furring strip  61 N centrally located on the opposite side of WRB  60 . As shown, furring strips  61  include an upper wall and a lower wall with partitioning elements  61 P interconnecting upper and lower walls,  61 UW and  61 LW, forming passageways  61 P to promote drainage and drying therethrough. The illustrated furring strip  61  is but one example of many types that could be utilized. Additional types of furring strips include but are not limited to extruded expanded polystyrene, molded expanded polystyrene, polyurethane or polyethylene closed cell foam, or other non-absorptive spacer materials. The WRB sheets include but are not limited to polymeric, paper and felt type products. The type of WRB  60  may be changed as well as the manner of attaching the furring strips  61  to the WRB. As an alternative to furring strips with passageways, the furring strips may have exterior grooves therein that serve as passageways for air, moisture and water. Although reference is made to the passage of air, moisture and water through passageways,  61 P, this is not the primary path for drainage and drying. The primary area for drainage and drying is the space or areas between adjacent furring strips  61 , the underlying components and exterior cladding.  
      Referring now to  FIG. 4 , there is shown a vertical sectional view taken along the plane  4 - 4  of  FIG. 1 . This is a sectional view through the wall of the garage illustrating the relationship of the sheetrock  75 , insulation  73  WRB  60 , sheathing  70 , and siding  80 . Positioned at the bottom of the air ventilation passageway is a screening  65  that serves to limit the entrance of common insects into vertical passageways.  
      Referring now to  FIG. 5 , there is shown an enlarged view of the area within the oval marked  FIG. 5 . As shown, narrower furring strip  61 N is placed against sheathing  70  with wider strip  61 W immediately beneath siding  80 .  
      Referring now to  FIG. 6 , there is shown a sectional view taken along the plane  6 - 6  of  FIG. 4 , illustrating an enlarged showing of the structure found in  FIG. 4 . It is to be kept in mind that not only is there drainage and drying through passageways  61 P of furring strips  61 W and  61 N (found in  FIG. 3 ), there is more substantial areas for drainage and drying between adjacent furring strips  61 W and  61 N thus ensuring that water between WRB  60  and sheathing  70  and between WRB  60  and siding  80 , will be contained and eliminated due to drainage and drying therebetween.  
      While the invention has been described in its preferred embodiment, it is to be understood that the words which have been used are words of description rather than words of limitation and that changes may be made within the purview of the appended claims without departing from the full scope or spirit of the invention. Accordingly, the present invention is to be limited only by the appended claims, and not by the foregoing specification.