Fastener, roofing system and method

Abstract

The present disclosure relates to a penetrating fastener for a roofing system having a flexible waterproof membrane adhesively attached to an upper layer which is fastened to a roof deck. The fastener is dimensioned to extend through the upper layer and threadingly engage the lower roof deck. The fastener includes a self-drilling tip for piercing the upper layer and the roof deck and a self-tapping threaded shank portion located above the tip. An unthreaded shank portion is located adjacent the threaded shank portion. A tapered collar is located above the unthreaded shank portion. The fastener further includes a driving head which has a flange extending at an angle from a first side of the head to the tapered collar for reducing the tensile forces associated with the head being installed flush with or slightly below the upper layer. The unthreaded shank portion, tapered collar and driving head together form an unthreaded length of the penetrating fastener that is at least as great as a thickness of a portion of the upper layer. A method includes attaching a roofing system using the penetrating fasteners.

1 . A penetrating fastener for an associated roofing system having a flexible waterproof roof membrane, an upper layer covered by the roof membrane, and a lower roof deck, the penetrating fastener dimensioned to extend through the upper layer and threadingly engage the lower roof deck, the fastener comprising: 
 a self-drilling tip for piercing the upper layer and the roof deck;    a self-tapping threaded shank portion located above the tip;    an unthreaded shank portion located above the threaded shank portion;    a tapered collar located above the unthreaded shank portion; and,    a driving head located above the tapered collar, said driving head including opposing first and second sides and a flange extending from the first side of the head to the tapered collar.    
   
   
       2 . The fastener of  claim 1 , wherein the upper layer of the associated roofing system includes first and second vertically stacked sections with the first section having a first thickness, and wherein the unthreaded shank portion, the tapered collar and the driving head comprise an unthreaded portion extending from the second side of the driving head to a distal end of the unthreaded shank portion, the unthreaded portion having an unthreaded length that is one of equal to or greater than the first thickness.  
   
   
       3 . The fastener of  claim 2 , wherein the second section of the upper layer has a second thickness and includes a foam core having a first surface and an opposing second surface, the lower roof deck has a deck thickness, and the self-drilling tip and the self-tapping threaded shank portion comprise a threaded portion of the penetrating fastener having a threaded length greater than the sum of the second thickness and the deck thickness.  
   
   
       4 . The fastener of  claim 2 , wherein the first section of the upper layer is a structural section that includes a sheet of material selected from a group consisting of oriented strand board (OSB) and plywood, the first thickness of the first section being approximately 7/16 inches, and the unthreaded shank portion of the penetrating fastener having an axial length of at least approximately ½ inch.  
   
   
       5 . The fastener of  claim 1 , wherein at least the threaded shank portion includes a plurality of threads extending at from 12 threads per inch to 14 threads per inch.  
   
   
       6 . The fastener of  claim 1 , wherein the head has an axial length of from approximately 0.025 to approximately 0.035 inches.  
   
   
       7 . The fastener of  claim 1 , wherein the flange of the head extends from the first side of the head to the tapered collar at an angle between about 9° and about 20°.  
   
   
       8 . The fastener of  claim 1 , wherein the driving head has a diameter from approximately 0.49 to approximately 0.53 inches.  
   
   
       9 . The fastener of  claim 1 , wherein the tapered collar of the fastener has a taper angle between about 25° and about 35°.  
   
   
       10 . The fastener of  claim 1 , wherein the second side of the driving head includes a non-circular recess.  
   
   
       11 . A roof system for application to an associated roof deck, the roof system comprising: 
 a first layer including first and second vertically stacked sections, the first section being a structural performance section having a first thickness, and the second section being a thermal performance section having a second thickness;    at least one penetrating fastener for attaching the first layer to the associated roof deck, the fastener including:    a self-drilling tip for piercing the first layer and the associated deck,    a self-tapping threaded shank portion located adjacent the tip for threadingly engaging a portion of the first layer and a portion of the associated roof deck,    a unthreaded shank portion located adjacent the self-tapping threaded shank portion,    a tapered collar located above the unthreaded shank portion, and,    a driving head located adjacent the tapered collar, and including a non-circular recess and a flange extending at an angle from a first side of the head to the tapered collar for reducing the tensile forces associated with the head being installed flush with or slightly below the first layer; and,    a flexible, water impermeable second layer adapted to sealingly engage the first layer and the at least one penetrating fastener.    
   
   
       12 . The system of  claim 11 , wherein the first thickness of the first section is approximately 7/16 of an inch.  
   
   
       13 . The system of  claim 11 , wherein the second section includes a foam core having a first surface and a second surface and a reinforced mat secured to the first surface of the foam core.  
   
   
       14 . The system of  claim 11 , wherein the second layer includes a synthetic polymer selected from a group consisting of an ethylene propylene diene rubber and thermoplastic polyolefin.  
   
   
       15 . The system of  claim 11 , wherein the at least one penetrating fastener includes a plurality of penetrating fasteners disposed in spaced apart relation along the first layer to secure the first layer to the associated roof deck.  
   
   
       16 . The system of  claim 11 , wherein the unthreaded shank portion, the tapered collar and the driving head comprise an unthreaded length of the at least one penetrating fastener, and the unthreaded length is one of equal to or greater than the first thickness of the first section.  
   
   
       17 . The system of  claim 11 , wherein the self-drilling tip and self-tapping threaded shank portion comprise a threaded length of the at least one penetrating fastener, the associated roof deck has a deck thickness, and the threaded length is one of equal to or greater than a sum of the second thickness and the deck thickness.  
   
   
       18 . A method of attaching a flexible waterproof membrane and a first layer of roofing material to a roof deck, the first layer of roofing material including first and second vertical sections, and the first section being a structural performance section having a first thickness, the second section being a thermal performance section having a second thickness, the method comprising the steps of: 
 positioning the first layer upon the roof deck;    piercing the first layer with a plurality of fasteners;    installing a head of each fastener flush with or slightly below the first layer;    threadingly engaging the deck with a threaded shank portion of each fastener thereby securing the first layer to the roof deck; and,    positioning the membrane over the first layer and the plurality of fasteners.    
   
   
       19 . The method of  claim 18  comprising the further step of extending an unthreaded shank portion of each fastener through the first thickness of the first section.  
   
   
       20 . The method of  claim 18  comprising the further steps of folding a first portion of the membrane onto itself to expose an underside surface of the first portion of the membrane: 
 applying a bonding adhesive to a portion of the underside surface of the first portion of the membrane to be secured to the first layer;    rolling the adhesive coated first portion of the membrane onto the first layer;    folding a second, un-adhered portion of the membrane onto the adhesively secured first portion of the membrane to expose an underside surface of the second portion of the membrane;    applying a bonding adhesive to a portion of the underside surface of the second portion of the membrane to be secured to the first layer; and,    rolling the adhesive coated second portion of the membrane onto the first layer.