Double barbed plate with fastener

Abstract

A two-piece fastener plate and fastener assembly and method of securing a roof membrane to a roof deck wherein the fastener is reinforced with concentric dome-shaped ribs separated by concentric depressions or dimples. The concentric depressions or dimples are provided with pairs of barbs for gripping the roof membrane when the fastener secures the roof membrane to the roof deck.

What is claimed is:  
     
         1 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of circular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and    d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;    e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;    g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         2 . The two-piece fastener assembly of  claim 1  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         3 . The two-piece fastener assembly of  claim 1  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         4 . The two-piece fastener assembly of  claim 1  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         5 . The two-piece fastener assembly of  claim 1  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         6 . The two-piece fastener assembly of  claim 1  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         7 . The two-piece fastener assembly of  claim 1  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         8 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of elliptical configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and    d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above said fastener plate;    e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;    g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         9 . The two-piece fastener assembly of  claim 8  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         10 . The two-piece fastener assembly of  claim 8  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         11 . The two-piece fastener assembly of  claim 8  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         12 . The two-piece fastener assembly of  claim 8  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         13 . The two-piece fastener assembly of  claim 8  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         14 . The two-piece fastener assembly of  claim 8  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         15 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of square configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and    d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;    e) a first concentric dimple between said-first dome-shaped concentric rib and said second dome-shaped concentric rib;    f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;    g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         16 . The two-piece fastener assembly of  claim 15  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         17 . The two-piece fastener assembly of  claim 15  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         18 . The two-piece fastener assembly of  claim 15  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         19 . The two-piece fastener assembly of  claim 15  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         20 . The two-piece fastener assembly of  claim 15  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         21 . The two-piece fastener assembly of  claim 15  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         22 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of rectangular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and    d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;    e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;    g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         23 . The two-piece fastener assembly of  claim 22  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         24 . The two-piece fastener assembly of  claim 22  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         25 . The two-piece fastener assembly of  claim 22  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         26 . The two-piece fastener assembly of  claim 22  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         27 . The two-piece fastener assembly of  claim 22  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         28 . The two-piece fastener assembly of  claim 22  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         29 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of circular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate;    d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         30 . The two-piece fastener assembly of  claim 29  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         31 . The two-piece fastener assembly of  claim 29  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         32 . The two-piece fastener assembly of  claim 29  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         33 . The two-piece fastener assembly of  claim 29  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         34 . The two-piece fastener assembly of  claim 29  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         35 . The two-piece fastener assembly of  claim 29  wherein said pair of barbs are substantially evenly spaced from each other.  
     
     
         36 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of elliptical configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate;    d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         37 . The two-piece fastener assembly of  claim 36  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         38 . The two-piece fastener assembly of  claim 36  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         39 . The two-piece fastener assembly of  claim 36  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         40 . The two-piece fastener assembly of  claim 36  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         41 . The two-piece fastener assembly of  claim 36  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         42 . The two-piece fastener assembly of  claim 36  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         43 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of square configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate;    d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         44 . The two-piece fastener assembly of  claim 43  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         45 . The two-piece fastener assembly of  claim 43  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         46 . The two-piece fastener assembly of  claim 43  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         47 . The two-piece fastener assembly of  claim 43  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         48 . The two-piece fastener assembly of  claim 43  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         49 . The two-piece fastener assembly of  claim 43  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         50 . A two-piece fastener assembly for securing a roof membrane to an underlying roof deck comprising: 
 a fastener plate of rectangular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:    a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;    b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;    c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate;    d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;    e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;    and wherein said fastener is a screw member having threads thereon.    
     
     
         51 . The two-piece fastener assembly of  claim 50  wherein said multiple pairs of barbs are extending 90° downward from the bottom surface of said fastener plate.  
     
     
         52 . The two-piece fastener assembly of  claim 50  wherein said multiple pairs of barbs are of triangular configuration.  
     
     
         53 . The two-piece fastener assembly of  claim 50  wherein said multiple pairs of barbs are of rectangular configuration.  
     
     
         54 . The two-piece fastener assembly of  claim 50  wherein said multiple pairs of barbs are of semi-circular configuration.  
     
     
         55 . The two-piece fastener assembly of  claim 50  wherein said fastener plate is formed of stainless steel or galvanized steel.  
     
     
         56 . The two-piece fastener assembly of  claim 50  wherein said pairs of barbs are substantially evenly spaced from each other.  
     
     
         57 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of circular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;  
 e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;  
 g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.    
     
     
         58 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of ellipsoidal configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;  
 e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;  
 g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.    
     
     
         59 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of square configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;  
 e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;  
 g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.    
     
     
         60 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of rectangular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a third dome-shaped concentric rib spaced from said second dome-shaped concentric rib rising above the top surface of said fastener plate;  
 e) a first concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 f) a second concentric dimple between said second dome-shaped concentric rib and said third dome-shaped concentric rib;  
 g) a flat concentric surface extending between said third dome-shaped concentric rib and said circumferential edge; wherein at least one of said first or second concentric dimples or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.    
     
     
         61 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of circular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.    
     
     
         62 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of elliptical configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said paisr of barbs piercing said roof membrane.    
     
     
         63 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of square configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.    
     
     
         64 . A method of securing a roof membrane to a roof deck comprising the steps of: 
 1) providing a two-piece fastener assembly comprising: 
 a fastener plate of rectangular configuration defined by a top surface, a bottom surface, and a circumferential edge, said fastener plate comprising:  
 a) an opening in its center portion for receiving a fastener therethrough for securing the fastener plate to a roof deck;  
 b) a first dome-shaped concentric rib rising above the top surface of said fastener plate;  
 c) a second dome-shaped concentric rib spaced from said first dome-shaped concentric rib rising above the top surface of said fastener plate; and  
 d) a concentric dimple between said first dome-shaped concentric rib and said second dome-shaped concentric rib;  
 e) a flat concentric surface extending between said second dome-shaped concentric rib and said circumferential edge; wherein at least one of said concentric dimple or said flat concentric surface is provided with multiple pairs of barbs extending downward from the bottom surface of said fastener plate;  
   2) placing a roof membrane having a top surface on a roof deck;    3) placing said fastener plate on said roof membrane with its bottom surface projecting toward the top surface of said roof membrane;    4) inserting said fastener through said opening in said fastener plate; and    5) threading said fastener through the roof membrane into said roof deck to fasten the roof membrane to the roof deck without said pairs of barbs piercing said roof membrane.