The present invention relates to a roof structure for a lightweight film-based greenhouse which, more particularly, can be installed only with aluminum bars and cover materials when the roof structure for the lightweight film-based greenhouse is designed, and can increase binding force by comprising a ridge, roof rafters, and a fixation means for connecting posts to the roof rafters. Unlike a glass-based greenhouse, a roof unit of the lightweight film-based greenhouse is formed by using a lightweight cover material. Thus, an iron material is formed in the shape of a thrust a C-shaped steel pipe or a pipe is fixated on the thrust in the direction perpendicular to the thrust aluminum rafters and the ridge or the like are fixated on the C-shaped steel pipe or the pipe and the roof unit is covered. Therefore, the roof structure of the lightweight film-based greenhouse is complicated and installation costs increase. According to the present invention, the roof structure for the lightweight film-based greenhouse is provided by suggesting the roof structure which can be installed only with aluminum bars and cover materials, like a glass-based greenhouse with a heavy weight. The ridge, the roof rafters, and the fixation means, formed as fixating tools in the shapes of rectangular pipes, for connecting posts to the roof rafters are fixated to each other to increase binding force. Sealing rubber is forcibly joined to a ceiling unit and connecting end portions of the ridge in order to increase sealing properties. Water leakage is prevented by increasing sealing properties of the lightweight ceiling unit as stopper rubber is joined to a rear end portion of a rotation end portion of the ceiling unit.COPYRIGHT KIPO 2016본 발명은 경질필름 온실의 지붕구조를 설계함에 있어서, 더 상세하게는 알루미늄바와 피복재만으로 설치가 가능하도록 한 것으로, 용마루와 지붕서까래, 그리고 기둥과 지붕서까래를 연결하는 고정수단을 구성하여 지지결속력을 증가시킬 수 있도록 한 경질필름 온실 지붕구조에 관한 것이다.경질 필름 온실은 유리온실과 달리 경량 피복재를 이용한 관계로 지붕부를 구성함에 있어서 철재를 트러스 형태로 제작하여 트러스 위에 트러스 직각 방향으로 C형강이나 파이프를 고정하고 그 위에 알루미늄
