古蹟修復磚牆灰作層添加疏水性摻料之防水透濕性能探討

Waterproof Properties and Moisture Permeability of Lime Plaster Layers Containing Hydrophobic Additives in Brick Walls of Restored Heritage

臺灣為海島型氣候，長期處於高溫高濕的環境，氣象條件反覆變化的情況之下，材料會因膨脹收縮產生自然老劣化，造成龜裂或起甲等物理性損壞；為保護磚石砌築的建築構造，先人們就近使用容易取得的生物灰與麻絨，作為表面粉刷材料。本研究探討了灰作層在磚牆的防水透濕性能，藉由添加疏水材料，減少側向水滲入灰作層的影響，並保持牆體的透氣性，以避免過多的水氣損壞古蹟的牆面（地仗層、彩繪層）。邀請匠師以其目前修復磚造古蹟的方法砌築14座試驗牆，在灰作材料中加入不同比例的疏水材料予以粉刷（灰作層），找出不同試驗磚牆和灰作層的水氣遷移，最後根據實測結果整理出較佳的疏水材料添加比例和施工注意事項，作為古蹟修復之參考。

Taiwan is an island divided between tropical and subtropical climate zones. Because of the persistent high temperatures and humidity and recurrent meteorological changes in Taiwan, materials naturally deteriorate because of expansion and contraction, which causes physical damage such as cracking and scaling. To protect the structures of brick buildings, the ancestors of contemporary Taiwanese people used readily available bio-ash and hemp fiber as materials for surface plastering. This study explored the waterproof properties and moisture permeability of the lime plaster layers in brick walls. Incorporating Hydrophobic Additives can reduce the impact of lateral water infiltrating the lime plaster layers while preserving the permeability of the wall, thereby protecting the wall (specifically its base and painted layers) from damage due to excess moisture. In this study, craftsmen were invited to construct 14 test walls through bricklaying by using their current methods of restoring brick heritage buildings. Different concentrations of Hydrophobic Additives were incorporated into the material used for plastering (lime plaster layer), and the moisture migration in different test brick walls and their lime plaster layers was measured. Finally, the optimal concentration of Hydrophobic Additives and precautions for construction were determined according to the actual measurement results. The results of this study may serve as references for heritage restoration.