Investigation on the optimum copper plate placement for traditional Japanese-style Shake roof

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K01089
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 03060:Cultural assets study-related
• Research Institution: Kyoto University
• Principal Investigator: Fujiwara Yuko 京都大学, 農学研究科, 研究員 (60506088)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: こけら葺屋根 / 葺込銅板 / 銅元素量

Outline of Final Research Achievements

The present research investigated the effect of roof slope and setback distance for inserted copper plates on the distribution of copper elements on traditional Japanese-style shake roof models exposed to the outdoors for about 2 years. Copper elements were detected earlier and accumulated in greater amounts in models with gentle roof slopes and copper plates set closer to the eave-side edge. And this research also investigated the amount of copper elements on the exposed part of shakes in the shake roof 5 and 45 years after construction. The amount of copper elements was 1/3 to 1/2 of commercial preservative-treated wood in roofs 5 years old and equal or higher in roofs 45 years old. These results can be used to derive a predictive equation for copper distribution on the roof, which can then be used to determine the optimal placement of the copper plates.

Free Research Field

木材加工

Academic Significance and Societal Importance of the Research Achievements

こけら葺屋根が次の葺替えまで健全な状態を保つための工夫の一つとして葺込銅板が設置されているがその最適な配置は建物の立地や屋根の方位・形状等によって異なり，現場では試行錯誤が続いている。本研究では屋根勾配および銅板の配置の異なる屋根モデルについて銅元素付着量の経時変化を調べた他，施工年数の異なる実際の屋根の銅元素分布を明らかにした。これらの結果を利用して銅付着量の予測式を導出すれば葺込銅板の最適配置を決める一助となる。