Patent ID: 8323801

Claim:
A construction barrier layer comprising: a porous moisture vapor permeable sheet selected from the group consisting of nonwoven fabrics, woven fabrics, microporous films, microperforated films and composites thereof, having first and second outer surfaces and at least one multilayer coating comprising: a metal coating having a thickness between about 15 nanometers and 200 nanometers deposited on the first outer surface of the moisture vapor permeable sheet; a synthetic metal oxide coating having a thickness of less than about 10 nm and having at least 72% Al 2 O 3 as measured by ESCA at a sampling depth of either 5 nm or 10 nm; and an outer organic coating having a thickness between about 0.05 μm and about 1 μm deposited on the metal layer; wherein the multilayer coating substantially covers the outer surface of the moisture vapor permeable sheet while leaving the pores substantially uncovered.