FIREPROOF CONSTRUCTION OF GUIDE RAIL OF WINDOW SHUTTER

PROBLEM TO BE SOLVED: To improve fireproof performance of a guide rail structure.SOLUTION: In an internal space formed between a first side edge 30 of a guide rail 3 located closer to an external wall and a second side edge 31 thereof facing an outdoor space, a reinforcement plate 7 formed of a material having a melting point higher than that of a material forming the guide rail 3 is provided on at least a part of the inner surface facing the outdoor space including the second side edge 31 so as not to project toward a guide space G. The reinforcement plate 7 part provided on the inner surface of the second side edge 31 has a width dimension so as to face a slat end received in the guide space G. A storage space extending in a height direction is located in the internal space of the guide rail 3 so as not to project toward the guide space G. A thermal expansion fireproof member 8 extending in a height direction is stored in the storage space so as not to project toward the guide space G at ordinary temperature.