| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceiling board causing little chipping of a lower end corner part of both side end parts at execution work in the ceiling board composed of a mineral fiberboard. SOLUTION: This ceiling board is constituted so that a lower half part in both side end parts of the ceiling board A is cut out in a cross-sectional inverse L shape, an upper half part is formed as locking projection strip parts 2 and 2 horizontally projected outside from the upper end of cutout step parts 1 and 1, and an under surface of these locking projection strip parts 2 and 2 is stretched in an installing state between ceiling board receiving surfaces 12 and 12 of ceiling board receiving frames 11 and 11 arranged in parallel. The lower end corner part of the cutout step parts 1 is formed as a projecting circular arc-shaped curved surface causing little chipping even if the ceiling board A collides with the receiving frames 11 at execution work. |
