metal roof might have the advantage of avoiding dripping, from the fact that it would interpose a barrier between the moist air and the cold surface of the underside of the roof....To accomplish this it will be necessary to put the paper on very carefully, making tight joints along the rafters. —from Carpentry & Building, March 1887 (courtesy G.E. Hahns, USDA forest Products Lab) by Bill Rose Three separate studies, along with reports in the press about them, have raised serious questions about vapor barriers, sparking controversy and confusion among people in the building trades. A look at the facts, however, quickly puts the matter to rest. Vapor barriers are just as important as ever. Oregon Research Research
