Composite membrane for building applications
A roofing composite membrane includes a base layer including a first thermoplastic polyolefin. A weight of the base layer is between 5 and 25 grams per square foot. A coating layer at least partially coats the base layer. The coating layer includes at least one inorganic additive, and a second thermoplastic polyolefin including polypropylene and having a melt flow rate between 0.5 grams per 10 minutes and 12 grams per 10 minutes.
1. A roofing system, comprising:
a steep sloped roof comprising a substrate; and
a roofing composite membrane installed on the substrate,
wherein the roofing composite membrane
is in the form of a sheet,
has a width of at least 2 feet,
is not a shingle, and
is not covered by a shingle,
the roofing composite membrane comprising:
a coating layer comprising:
at least one inorganic additive, and
a first thermoplastic polyolefin comprising polypropylene, wherein the first thermoplastic polyolefin has a melt flow rate between 0.5 grams per 10 minutes and 12 grams per 10 minutes,
wherein the coating layer comprises a top surface and a bottom surface opposite the top surface,
wherein the top surface of the coating layer forms a top surface of the roofing system; and
a base layer comprising a second thermoplastic polyolefin,
wherein the base layer comprise a top surface and a bottom surface opposite the top surface,
wherein the bottom surface of the coating layer at least partially covers the top surface of the base layer; and
an adhesive layer,
wherein the adhesive layer at least partially covers the bottom surface of the base layer.
2. The roofing system of claim 1 , wherein the the coating layer comprises polyethylene.
3. The roofing system of claim 1 , wherein the first thermoplastic polyolefin comprises at least 80 mol % polypropylene.
4. The roofing system of claim 1 , wherein the coating layer has a flexural modulus between 5,000 psi and 175,000 psi.
5. The roofing system of claim 1 , wherein the base layer has a tear strength between 10 lbf and 30 lbf.
6. The roofing system of claim 1 , wherein the at least one inorganic additive comprises CaCO 3 , Mg(OH) 2 , TiO 2 , colorants, fire retardants, or combinations thereof.
7. The roofing system of claim 1 , wherein the base layer comprises a woven or nonwoven fabric.
8. The roofing system of claim 1 , further comprising an adhesive layer in contact with the base layer, wherein the adhesive layer comprises a butyl, styrene, or acrylic hot melt.
9. The roofing system of claim 1 , wherein a combined thickness of the base layer and the coating layer is between 6 mils and 40 mils.
10. The roofing system of claim 1 , wherein a weight of the base layer is between 5 and 25 grams per square foot.
11. The roofing system of claim 1 , wherein the roofing membrane comprises a thin, pliable sheet.
12. The roofing system of claim 1 , wherein the width of the roofing membrane is 2 to 8 feet.
13. The roofing system of claim 1 , wherein the width of the roofing membrane is 2 to 4 feet.
14. The roofing system of claim 1 , wherein the width of the roofing membrane is 2 to 6 feet.
15. The roofing system of claim 1 , wherein the width of the roofing membrane is 4 to 8 feet.
16. The roofing system of claim 1 , wherein the width of the roofing membrane is 4 to 6 feet.