Insect net greenhouse Flat roof structure,span: 4.2M, section:3.8M; Wind load: 0.75 KN/M2; The frame works structure is consisting of main poles, self-made specialmetal profiels, O shape PP pressing bar and various joints.It is prefabricatedstructure without any welding point. All material is hot galvanized with zinc cover 275g/M2; Covering is insect net or shade net with anti-UV; Double insect insulated doors;