Roofing seam with reactive adhesive

Abstract

A roofing system includes a first membrane, second membrane and an adhesive layer with no VOC content. A portion of the second membrane overlaps a portion of the first membrane. The adhesive layer directly adheres the overlapping portions of the first membrane and the second membrane together.

What is claimed is: 
     
         1 . A roofing system comprising:
 a first membrane:   a second membrane, a portion of the second membrane overlapping a portion of the first membrane; and   an adhesive layer directly adhering the overlapping portions of the first membrane and the second membrane together, the adhesive layer having no VOC content.   
     
     
         2 . The roofing system of  claim 1  wherein the adhesive layer is the product of mixing an A side composition and a B side composition together. 
     
     
         3 . The roofing system of  claim 2  wherein the B side composition includes a polyol, a catalyst and a chain extender, and wherein the A side composition includes at least one of a polyurethane prepolymer and a diisocyanate. 
     
     
         4 . The roofing system of  claim 3  further comprising at least one adhesion promoter present in at least one of the A side and the B side. 
     
     
         5 . The roofing system of  claim 4  wherein the at least one adhesion promoter is selected from the group consisting of chlorinated paraffins and chlorinated polyolefins. 
     
     
         6 . The roofing system of  claim 4  wherein the at least one adhesion promoter includes at least two adhesion promoters each selected from the group consisting of chlorinated paraffins and chlorinated polyolefins. 
     
     
         7 . The roofing system of  claim 2  wherein a ratio of isocyanate groups in the A side to hydroxyl groups in the B side is greater than 1.5:1. 
     
     
         8 . The roofing system of  claim 1  wherein the adhesive layer further includes a blowing agent. 
     
     
         9 . The roofing system of  claim 1  wherein the first membrane and the second membrane are unprimed prior to the application of the adhesive layer. 
     
     
         10 . The roofing system of  claim 1  wherein the first membrane and the second membrane are sheets of EPDM. 
     
     
         11 . The roofing system of  claim 1  wherein the adhesive layer is a one-part composition including at least one poyol, at least one moisture cure prepolymer, and at least one catalyst. 
     
     
         12 . A composite roof structure comprising:
 a roofing substrate having a substrate surface;   a first roofing membrane having a membrane surface that opposes the substrate surface of the roofing substrate;   a second roofing membrane having a membrane surface that opposes the substrate surface of the roofing substrate, a portion of the second roofing membrane overlapping a portion of the first roofing membrane and   an adhesive layer directly adhering to the substrate surface of the roofing substrate and directly adhering to the membrane surface of the first roofing membrane and to the membrane surface of the second roofing membrane; and   a splice adhesive layer directly adhering the overlapping portions of the first roofing membrane and the second roofing membrane together, the splice adhesive layer having no VOC content.   
     
     
         13 . The roofing structure of  claim 12  wherein the adhesive layer and the splice adhesive layer of made of the same adhesive composition. 
     
     
         14 . The roofing structure of  claim 12  wherein the adhesive layer and the splice adhesive layer are the product of mixing an A side composition and a B side composition together. 
     
     
         15 . The roofing structure of  claim 14  wherein the B side composition includes a polyol, a catalyst and a chain extender, and wherein the A side composition includes at least one of a polyurethane prepolymer and a diisocyanate. 
     
     
         16 . The roofing structure of  claim 15  further comprising at least one adhesion promoter present in at least one of the A side and the B side. 
     
     
         17 . The roofing structure of  claim 16  wherein the at least one adhesion promoter is selected from the group consisting of chlorinated paraffins and chlorinated polyolefins. 
     
     
         18 . The roofing structure of  claim 16  wherein the at least one adhesion promoter includes at least two adhesion promoters each selected from the group consisting of chlorinated paraffins and chlorinated polyolefins. 
     
     
         19 . The roofing structure of  claim 14  wherein a ratio of isocyanate groups in the A side to hydroxyl groups in the B side is greater than 1.5:1. 
     
     
         20 . The roofing structure of  claim 12  wherein the first roofing membrane and the second roofing membrane are unprimed prior to the application of the splice adhesive layer. 
     
     
         21 . The roofing structure of  claim 12  wherein the first roofing membrane and the second roofing membrane are sheets of EPDM. 
     
     
         22 . The roofing structure of  claim 12  wherein the adhesive layer and the splice adhesive layer are a one-part composition including at least one poyol, at least one moisture cure prepolymer, and at least one catalyst.