This is on a bank owned shell about 4 years old, exterior mostly installed, electric installed, but otherwise it's just studs inside. Exterior has a reflective material used as a weather barrier under vinyl siding. Same material was used on the bottom of the roof sheathing. Looks like a woven material with a foil coating? I found no markings on either side. Any idea what this is? Is it listed for use as a weather resistant barrier? If so, is it supposed to be sealed with UL-181 tape instead of lapped shingle-fashion? Click to Enlarge 62.71 KB Click to Enlarge 37.65 KB Click to Enlarge 54.13 KB