Film for construction and film combination

Abstract

A film ( 1 ) for construction with at least one functional layer ( 2 ) and optionally at least one other layer, especially a carrier layer and/or reinforcing layer ( 3 ), the functional layer ( 2 ) having a water vapor diffusion resistance (s d value) that is dependent on the ambient humidity. The functional layer ( 2 ) has at least one material ( 4 ) that can be obtained from a renewable raw material, especially at least one polymer based on a renewable raw material. A method of applying a functional layer to building construction involves installing the functional layer as a vapor control layer over rafters of a building either inside, outside or in a loop shape, or alternatively, installing the functional layer as a vapor control layer barrier in a sheeted roof, ceiling or façade region of a building as at least one of an underform web and a counter ceiling web.

What is claimed is: 
     
         1 . A building comprising a roof, said roof comprising rafters and a vapor control film combination comprising at least one functional layer and at least one carrier or reinforcing layer, the at least one functional layer having a water vapor diffusion resistance (s d  value) that is dependent on ambient humidity, wherein the functional layer is formed of a biodegradable polymer selected from the group consisting of a biodegradable polyester, a biodegradable polyhydroxyalkanoate, a biodegradable polylactide, a biodegradable polyester urethane and a biodegradable polysaccharide. 
     
     
         2 . The building of  claim 1 , wherein the vapor control film combination is disposed over the rafters of said roof 
     
     
         3 . The building of  claim 1 , wherein the vapor control film combination is disposed in a loop shape over said rafters. 
     
     
         4 . Method of applying a functional layer to building construction as at least one of a vapor control layer, an underform web and a counter ceiling web, comprising the steps of:
 providing an indefinite length of a functional layer having a water vapor diffusion resistance s d  value that is dependent on ambient humidity and a static water column water tightness of at least 10 cm, wherein the functional layer is formed of at least one renewable raw material, and   at least one of the following steps:   installing the functional layer as a vapor control layer inside, outside or in a loop shape over rafters of a building,   installing the functional layer as a vapor control layer barrier in a sheeted roof, ceiling or façade region of a building as at least one of an underform web and a counter ceiling web.   
     
     
         5 . Method of applying a functional layer to building construction according to  claim 4 , wherein both of said steps of installing the functional layer as a vapor control layer inside, outside or in a loop shape over rafters of a building, and installing the functional layer as a vapor control layer barrier in a sheeted roof, ceiling or façade region of a building as at least one of an underform web and a counter ceiling web are performed. 
     
     
         6 . Method of applying a functional layer to building construction according to  claim 4 , wherein said step of installing the functional layer as a vapor control layer inside, outside or in a loop shape over rafters of a building is performed. 
     
     
         7 . Method of applying a functional layer to building construction according to  claim 4 , wherein said step of installing the functional layer as a vapor control layer barrier in a sheeted roof, ceiling or façade region of a building as at least one of an underform web and a counter ceiling web is performed.