There is provided an article that includes a polymeric layer disposed on and covering a first major surface of an porous layer, an adhesive layer disposed on a second major surface of the elastic layer opposite the polymeric layer; and a liner disposed on a major surface of the polymeric layer opposite the first major surface of the elastic layer. The polymeric layer and the porous layer together form an air and water barrier that is water vapor permeable. The liner is water vapor impermeable. In a preferred embodiment the polymeric layer comprises a polyoxyalkylene polymer having at least one end group derived from an alkoxy silane. A method of applying the article to a surface of a building component is also provided.