The invention relates to a multi-layer weatherable film structure having an outer layer of a highly weatherable film, a layer having a high thermal deformation temperature, an optional tie layer, and a thin layer of polyolefin or polyamide. The highly weatherable film layer preferably is polyvinylidene fluoride. The polyolefin or polyamide layer is less than 500 microns in thickness, and preferably the whole film structure is less than 750 microns thick. The polyolefinjpolyamide side of the film structure can easily be adhered to many different substances—especially polyolefins and polyamides. This film can be used to provide a highly weatherable protective layer a substrate. One useful application for the film is in a photovoltaic module to protect the back side of the module from weathering and abrasion. The multi-layer film structure can be adhered to a typical polyolefin-based encapsulant layer and used as a backsheet encapsulant in a photovoltaic module.