This article deals with the hygrothermal performance of wooden beam ends embedded in brick masonry walls. The real-scale experiment involving three interior insulation systems with different water vapor resistances and different treatments of joist pockets was monitored for three consecutive years. The moisture load of test walls was controlled during the experiment. First, humidity of indoor air was increased in the cold season (2016–2017). Then, an artificial short-time intensive rain event brought liquid water onto the external surface of the test walls in July 2017. Despite relatively mild external climatic loads, relative humidity was unsatisfactorily high in unsealed joist pockets. Vapor and airtight sealing of the joist pockets improved the microclimate of the wooden beam ends. However, even in this case, relative humidity approached critical values for the onset of mold growth. The artificial rain load applied on the experimental walls noticeably worsened the hygrothermal conditions in the joist pockets. Relative humidity in the joist pockets further increased to a level where massive mold growth could be expected. Visual inspection of the wooden beam ends during reconstruction of the experiment, however, revealed only a small spot of mold on a single beam located in an unsealed joist pocket. Mold growth on samples of organic thermal insulation material was found by microscopic investigations. Molds were localized in small separated colonies. These in situ and laboratory investigations do not confirm the calculated values of mold growth index. In conclusion, sealing of wooden beam ends improved their hygrothermal performance in the experiment.

中文翻译：

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内保温砖石木梁端部的实验研究：暴露于半大陆气候条件的真实比例实验墙的测量数据

本文讨论嵌入砖砌墙的木梁端部的湿热性能。连续三年监测涉及三个具有不同水蒸气阻力和不同托梁袋处理方式的内部保温系统的真实规模实验。在实验过程中控制测试墙的水分负荷。首先，室内空气湿度在寒冷季节（2016-2017）增加。然后，2017 年 7 月的一次人工短时强降雨事件将液态水带到测试墙的外表面。 尽管外部气候负荷相对温和，但未密封的托梁袋中的相对湿度高得令人不满意。托梁口袋的蒸汽和气密密封改善了木梁末端的小气候。然而，即使在这种情况下，相对湿度接近霉菌生长开始的临界值。施加在实验墙上的人工雨水荷载明显恶化了托梁袋中的湿热条件。托梁袋中的相对湿度进一步增加到可以预期大量霉菌生长的水平。然而，在实验重建期间对木梁末端的目视检查发现，在未密封的托梁袋中的单个梁上只有一小块霉菌。通过显微研究发现有机隔热材料样品上的霉菌生长。霉菌位于分离的小菌落中。这些原位和实验室调查并未证实霉菌生长指数的计算值。总之，木梁端部的密封在实验中提高了它们的湿热性能。