| 摘要 |
PROBLEM TO BE SOLVED: To provide building boards capable of preventing any deterioration in their external appearance and quality. SOLUTION: A plurality of different kinds of projected portions 1 and 2 and recessed portions 3 each having different thickness are formed at random on the surfaces of substrata of building boards 4. Each surface of a substratum at the end portion of the building board 4 is formed as a plane 5 having a reference thickness located between the smallest projected thickness portion and the smallest recessed thickness portion 3. A falling sloped surface 6 is formed from the smallest thickness portion 1 adjacent to the reference thickness portion 5 toward the reference thickness portion 5; and also a rising sloped portion 7 is formed from the recessed portion 3 adjacent to the reference thickness portion 5 to the reference thickness portion 5. The thickness of the board sequentially varies with a projected portion 1 having the smallest thickness; a falling sloped surface 6; a reference thickness portion 5; a rising sloped surface 7; and a recessed portion 3. Therefore, rainwater or the like is hardly accumulated on the surface of the building boards. COPYRIGHT: (C)2008,JPO&INPIT
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