Fire doors - Rubner internal doors protect against fire In schools, kindergartens, old people's homes, all public buildings, hotels and restaurants, where fire doors are required by the law. This is the reason why Rubner Doors has dedicated so much attention to the development of safety doors conforming to standards. Rubner Türen Inc. produces firedoors in Classes REI 15 (resistance to fire for 15 minutes), 30, 60, 90 and 120. Competence in production and more than thirty years experience allow Rubner to produce almost all inside doors in the firedoor version too.