Permeable water resistive roof underlayment
The present invention relates to a water resistant, UV resistant, vapor permeable, air barrier roofing underlayment assembly for use on flat or low sloped roofs comprising a substrate of permeable polyester, a permeable copolymer acrylate coating bonded to the permeable polyester substrate and a pressure sensitive permeable copolymer adhesive secured to the acrylate coating. The permeable coating is a copolymer including a primary polymer of n-butyl acrylate and contains carbon black.
1. An underlayment for a roof having a slope angle of 5° or less, that is an air barrier and self-adhering, vapor-permeable, water-resistive, and UV-resistant, the underlayment comprising:
a substrate of polyester having a surface;
a foamed, permeable copolymer coating attached to the polyester substrate's surface, wherein the foamed, permeable copolymer coating includes an n-butyl acrylate copolymer that;
includes n-butyl acrylate in an amount ranging from 30% to 98% by weight, and
has a foam density that ranges from 50% to 65% of the copolymer's density before foaming; and
a permeable pressure-sensitive adhesive bonded to said foamed,
permeable copolymer coating; the underlayment having a permeability of 25 perms or more.
2. The underlayment as claimed in claim 1 , wherein the underlayment has a permeability of about 35 perms or more.
3. The underlayment as claimed in claim 1 , wherein the permeable-pressure-sensitive adhesive does not include a solvent.
4. The underlayment as claimed in claim 1 , wherein the foamed, permeable copolymer coating includes n-butyl acrylate copolymer with solids ranging from about 30% to about 55% of the foamed, permeable copolymer coating.
5. The underlayment as claimed in claim 1 , wherein the foamed permeable copolymer coating has a permeability that ranges from about 30 perms to about 60 perms.
6. The underlayment as claimed in claim 1 , wherein the polyester substrate ranges in thickness from about 180 mils to about 220 mils, and has a permeability that ranges from about 65 perms to about 80 perms.
7. The underlayment as claimed in claim 1 , wherein the foamed permeable copolymer coating includes carbon black.
8. A membrane for a flat or low sloped roof, that is an air barrier, and water-resistant, vapor-permeable, and self-adhering, the membrane comprising:
a substrate of polyester having a surface, and that is permeable and consists of a single ply;
a foamed, permeable n-butyl acrylate copolymer coating attached to the polyester substrate's surface, comprising n-butyl acrylate copolymer, wherein the n-butyl acrylate copolymer has a foam density that ranges from 50% to 65% of the n-butyl acrylate copolymer's density before foaming;
a pressure-sensitive, permeable, co-polymer acrylate adhesive bonded with the foamed, permeable n-butyl acrylate copolymer coating; and
wherein, the combination of the substrate, the foamed, permeable n-butyl acrylate copolymer coating, and the pressure-sensitive, permeable copolymer acrylate adhesive has a permeability that ranges from about 25 perms to about 45 perms.
9. The membrane of claim 8 wherein said low sloped roof has a sloped angle of 5° or less.
10. The membrane of claim 8 wherein the pressure-sensitive, permeable, copolymer acrylate adhesive includes a silicon release film.
11. The membrane as claimed in claim 8 wherein the foamed, permeable n-butyl acrylate copolymer coating includes carbon black.
12. The membrane of claim 8 wherein the foamed, permeable n-butyl acrylate copolymer includes solids ranging from about 20% to about 50%.
13. The membrane of claim 8 wherein the pressure-sensitive, permeable, copolymer acrylate adhesive includes a removable silicon release film mounted thereto to form an exterior surface of said roofing membrane.
14. A membrane laminate for a flat roof, that is an air barrier and water-resistant, UV-resistant, vapor-permeable, and self-adhering, the laminate comprising:
a substrate of polyester having a surface and that is vapor permeable;
a foamed, vapor-permeable, solvent-free, n-butyl acrylate copolymer coating attached to the polyester substrate's surface, wherein the foamed, vapor-permeable, solvent-free, n-butyl acrylate copolymer coating includes carbon black;
a permeable, pressure-sensitive, copolymer adhesive attached to the foamed, vapor-permeable, solvent-free, n-butyl acrylate copolymer coating, wherein the permeable, pressure-sensitive, copolymer adhesive is vapor permeable; and
wherein the combination of the substrate, the foamed, vapor-permeable, solvent-free, n-butyl acrylate copolymer coating, and the permeable, pressure-sensitive, copolymer adhesive has a permeability greater than 25 perms.
15. The membrane laminate as claimed in claim 14 wherein the foamed, vapor-permeable, solvent-free, n-butyl acrylate copolymer coating has a thickness ranging from about 80 mils to about 100 mils.
16. The membrane laminate as claimed in claim 14 wherein the membrane laminate is capable of supporting a water column at least 24 inches high for at least 48 hours.