Roofing underlayment
AssigneeFT Synthetics Inc.
InventorsGurpreet S. Sandhar, Kenneth Russell Robson, Sahar Khedri
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Abstract
A breathable synthetic roofing underlayment having a hydrophobic nonwoven layer on top to deflect water, a liquid water-resistant and vapour-permeable membrane layer in the middle, and a bottom nonwoven layer which is hydrophilic and has rapid and high liquid water absorbency. This accelerates the movement of liquid water from a roofing deck into the nonwoven bottom layer and increases the rate of transfer of water through the underlayment. The bottom layer comprises a carrier resin and a hydrophilic agent, which may be a polyamide such as polycaprolactam (Nylon 6) or poly(hexamethylene adipamide), a polysorbate or other composition. The underlayment is especially useful for application to wet roofing decks.
Claims40
A roofing underlayment comprising:
- (a) a first layer that is nonwoven, vapour-permeable, has a hydrophobic surface and low liquid water absorptive capacity, comprising a polymer or mixture of polymers, the first layer being an outer layer for contact with an exterior roofing material;
- (b) a second layer that is water vapour-permeable and a liquid water barrier, comprising a carrier resin and a breathability agent, and
- (c) a third layer for contact with a roofing deck, the third layer being nonwoven, hydrophilic and liquid water absorptive, the second layer being between the third layer and the first layer.
Dependencies are inferred from the claim text.