Ventilating moisture barrier for roof vent

Abstract

The present invention relates to a protective barrier adapted to fit over a roof vent, particularly an off-ridge roof vent, which provides for ventilation and also restricts pass-through of wind-driven rainwater. The barrier comprises two parallel orifice plates, such as louvered panels with passages, that are spaced apart a desired distance by a stagnation zone, so that the device is effective to reduce or eliminate of passage of wind-driven rainwater to the interior of the vent. In various embodiments, the number of louvers in the more outward-disposed orifice plate is greater than the number of louvers in the more inward-disposed orifice plate.

1 . A ventilating moisture barrier for covering a roof vent exterior aperture, the roof vent exterior aperture having a height and a width defined respectively by distances between a front lip and a bottom delineation, and a left side transversely spaced from a right side, the ventilating moisture barrier comprising: 
 a. a first, exterior orifice plate comprising a first number of exterior louvers extending transversely, and a plurality of exterior passages formed through the first orifice plate;    b. a second, interior orifice plate comprising a second number of interior louvers extending transversely, and a plurality of interior passages formed through the second orifice plate; and    c. a stagnation zone disposed and establishing a distance between the first orifice plate and the second orifice plate, the distance effective to reduce passage of wind-driven water droplets through the interior passages;    wherein the first number is greater than the second number, and wherein at least one of the exterior louvers is aligned laterally with one of the interior louvers.    
   
   
       2 . The ventilating moisture barrier of  claim 1 , additionally comprising a top flange and a bottom flange providing respective surface or holes for means for attachment, respectively, to the top lip and a portion of roof below the bottom delineation.  
   
   
       3 . The ventilating moisture barrier of  claim 1 , wherein at least half of the exterior louvers is aligned laterally with the interior louvers.  
   
   
       4 . The ventilating moisture barrier of  claim 2 , the interior louvers having a lateral depth measured between a first end and a second end, wherein the stagnation zone distance is at least the lateral width.  
   
   
       5 . The ventilating moisture barrier of  claim 4 , wherein the stagnation zone distance is at least 1.50 times the lateral width.  
   
   
       6 . The ventilating moisture barrier of  claim 1 , the interior passages providing a first total open area greater than a second total open area of the exterior passages.  
   
   
       7 . The ventilating moisture barrier of  claim 2 , wherein the first number is seven and the second number is six.  
   
   
       8 . A ventilating moisture barrier comprising 
 a. a first orifice plate comprising a first number of interior louvers extending transversely, and a plurality of passages formed through the first orifice plate;    b. a second orifice plate comprising a second number of exterior louvers extending transversely, the exterior louvers having a depth from a first end to a second end, and a plurality of passages formed through the second orifice plate; and    c. a stagnation zone between the first orifice plate and the second orifice plate, establishing a distance effective to reduce passage of wind-driven water droplets through the second orifice passages;    wherein the first number is greater than the second number, and wherein the first orifice plate and the second orifice plate are positioned substantially parallel.    
   
   
       9 . The ventilating moisture barrier of  claim 8 , additionally comprising a top flange and a bottom flange providing respective surface or holes for means for attachment.  
   
   
       10 . The ventilating moisture barrier of  claim 8 , wherein at least half of the exterior louvers is aligned laterally with the interior louvers.  
   
   
       11 . The ventilating moisture barrier of  claim 8 , the interior louvers having a lateral depth measured between a first end and a second end, wherein the stagnation zone distance is at least the lateral width.  
   
   
       12 . The ventilating moisture barrier of  claim 11 , wherein the stagnation zone distance is at least 1.50 times the lateral width.  
   
   
       13 . The ventilating moisture barrier of  claim 11 , the plurality of passages formed through the second orifice plate providing a first total open area greater than a second total open area of the plurality of passages formed through the first orifice plate.  
   
   
       14 . The ventilating moisture barrier of  claim 11 , wherein the first number is seven and the second number is six.  
   
   
       15 . A roof vent comprising a bottom plate, a top surface, and side panels, and an exterior aperture having a height and a width defined respectively by distances between a front lip and a bottom delineation, and a left side transversely spaced from a right side, and a ventilating moisture barrier covering the exterior aperture, the ventilating moisture barrier comprising: 
 a. a first orifice plate comprising a first number of exterior louvers extending transversely, and a plurality of passages formed through the first orifice plate;    b. a second orifice plate comprising a second number of interior louvers extending transversely, the interior louvers having a depth from a first end to a second end, and a plurality of passages formed through the second orifice plate; and    c. a stagnation zone between the first orifice plate and the second orifice plate, establishing a distance effective to reduce passage of wind-driven water droplets through the second orifice passages; and    wherein the first number is greater than the second number, and wherein the first orifice plate and the second orifice plate are positioned substantially parallel.    
   
   
       16 . The roof vent of  claim 15 , wherein at least half of the exterior louvers is aligned laterally with the interior louvers.  
   
   
       17 . The roof vent of  claim 15 , the ventilating moisture barrier additionally comprising a top flange and a bottom flange providing respective surface or holes for means for attachment to, respectively, the front lip and a portion of bottom plate along the bottom delineation.  
   
   
       18 . The roof vent of  claim 15 , the interior louvers having a lateral depth measured between a first end and a second end, wherein the stagnation zone distance is at least the lateral width.  
   
   
       19 . The roof vent of  claim 15 , the plurality of passages formed through the second orifice plate providing a first total open area greater than a second total open area of the plurality of passages formed through the first orifice plate.  
   
   
       20 . The roof vent of  claim 15 , wherein the first number is seven and the second number is six.