Adhered roof structure
A membrane roof includes a supporting substrate covered with a roofing membrane. The roofing membrane is adhered to the substrate utilizing an adhesive such as a foam polyurethane adhesive. The adhesive has an elongation of at least 100% and a modulus no greater than 100 psi.
1. A roof structure comprising a roof membrane and a roof substrate, a first surface of said membrane adhered to said substrate by a foaming polyurethane adhesive, said adhesive having an elongation of at least about 100% and a modulus less than about 100 psi at 150% elongation;
wherein said polyurethane is formed from a polyol and an isocyanate prepolymer and wherein said polyol has a molecular weight of at least about 3000; and
wherein said isocyanate prepolymer has an isocyanate content of no greater than about 25% by weight.
2. The roof structure claimed in claim 1 wherein said first surface is a fibrous mat.
3. The roof structure claimed in claim 1 wherein said membrane is selected from the group consisting of polyvinyl chloride, thermoplastic olefin and EPDM.
4. The roof structure claimed in claim 1 wherein said adhesive has an elongation of at least about 150%.
5. The roof structure claimed in claim 4 wherein said adhesive has a modulus of 10 psi to about 100 psi at 150% elongation.
6. The roof structure claimed in claim 5 wherein said adhesive has a modulus of about 20 psi at 150% elongation.