| 摘要 |
PROBLEM TO BE SOLVED: To provide an opening building material that prevents a shutter slat from coming off, even when exposed to flame heat. ! SOLUTION: An opening building material includes a guide frame, an inside-of-groove reinforcement material, and an outside-of-groove reinforcement material. The guide frame has an outdoor side wall, an indoor side wall, a depth wall, and a groove surrounded by the three walls. The inside-of-groove reinforcement material, which is arranged in the groove of the guide frame, has an outdoor-side face piece, a depth piece and an indoor-side face piece. The outdoor-side face piece abuts on the outdoor side wall of the guide frame; the depth piece abuts on the depth wall of the guide frame; the indoor-side face piece abuts on the indoor side wall of the guide frame; and the outside-of-groove reinforcement material is arranged on the outside of the groove of the guide frame and abuts on the indoor side wall of the guide frame. The indoor side wall of the guide frame is co-fa |
