Single ply roofing system

Abstract

A single ply flexible membrane roofing system secured to a roof deck has a first membrane secured to the roof deck by fasteners. The membrane system includes a second membrane with an edge portion overlapping the first membrane edge which can be “factory” weld-bonded to the first membrane along the edge of the second membrane to provide waterproofing such that the first membrane edge projects forwardly from the bond to define a fastening projection extending forwardly from the weld bond for the laterally spaced fasteners. An adhesive coating over the fastening projection and fasteners extends essentially from the weld bond forwardly to provide a continuous adhesive coating over the first membrane projection and the fasteners to provide a substantially monolithic water-sealed seaming bond of enhanced strength with enhanced resistance to uplift forces. The invention is concerned also with the labor reduced method of constructing the system.

1 . A single ply membrane roofing system secured to a roof deck, said system comprising: 
 a first flexible membrane with a longitudinally extending first membrane free edge secured to said roof deck by transversely spaced fasteners, said roofing system having a second flexible membrane with a second membrane edge portion overlapping said first membrane free edge and weld bonded to said first membrane via a continuous weld bond along the second membrane edge portion such that said first membrane free edge projects forwardly from said bond to define a fastening projection for said fasteners extending forwardly from said weld bond; and    an adhesive coating over said fastening projection and fasteners, extending essentially from said weld bond forwardly to provide a continuous adhesive coating over said first membrane free edge and said fasteners providing a substantially monolithic bond comprising said weld bond and said adhesive coating.    
   
   
       2 . The first membrane roofing system of  claim 1  wherein said adhesive coating extends down said free edge to the level of said roof deck between said first membrane free edge and the underside of said second membrane.  
   
   
       3 . The first membrane roofing system of  claim 1  wherein said adhesive coating extends forwardly of said first membrane free edge for a restricted distance between said second membrane and said roof deck.