Investigating the performance of solid walls with water-repellent surface treatments

潮湿的实心墙比干墙具有较差的热性能，因此影响其能量性能。在未来的气候情景下，固体墙壁的含水量可能会增加，特别是由于降雨强度增加。此外，实墙保温改变了现有墙体的水分平衡;湿热模拟通常强调，如果要安装内墙保温，则需要额外的雨水保护。因此，对于面临更高暴露于大气介质的实墙建筑，提供雨水保护通常是必要的。传统的方法包括将添加剂（例如牛脂或亚麻籽油）掺入石灰水中，可能与粉刷和垫层砂浆结合使用，这可能会影响建筑物的美学外观，例如如果建筑物之前没有粉刷过。另一方面，有证据表明现代无色防水表面处理的长期有效性，这将使建筑物的美学外观得以保留。如果有效，这些表面处理有可能成为改善固体墙壁能源性能的技术。虽然防水剂可以带来好处，但过去有证据表明，有机硅防水表面处理的性能较差，与外表面的蒸汽渗透性降低有关。最近的发展，在化学成分的防水处理声称已改善这一特点。然而，长期性能存在不确定性，特别是对于不同矿物和孔隙率的建筑材料。在更广泛的层面上，几乎没有证据表明防水表面处理对建筑物能源性能的积极和长期不利影响，该研究旨在研究具有水的固体墙壁的长期湿热性能和有效性，防水表面处理。特别是，研究将解决以下研究问题，这是符合技术和系统性能和舒适，健康和福祉埃尔贝的主题：1。在传统的实心墙中已经存在哪些与防水表面处理有关的证据？2.这些处理方法对传统建筑物外墙材料的孔隙结构有何影响？3.这些处理方法对提高实心墙的热传递率有什么影响？4.经过防水表面处理的实心墙的长期湿热性能如何？5.防水表面处理对固体墙壁的长期不利影响和积极影响是什么？a.重新使用防水剂的长期有害和积极影响是什么？6.防水表面处理对实墙建筑的室内空气质量和能源性能有什么影响？

A damp solid wall has poorer thermal performance than a dry wall, hence affecting its energy performance. Under future climate scenarios, the moisture content of solid walls is likely to increase, particularly due to higher rainfall intensity. Moreover, solid wall insulation changes the moisture balance of the existing wall; hygrothermal simulations often highlight the need for additional rainwater protection if internal wall insulation is to be installed.Therefore, providing rainwater protection is often necessary for solid-wall buildings that are facing higher exposure to atmospheric agents. Traditional methods include incorporating additives (e.g. tallow or linseed oil) into limewash, perhaps in conjunction with rendering and bedding mortars, which might affect the aesthetic appearance of the building, e.g. if the building was not previously rendered. On the other hand, there is some evidence on the long-term effectiveness of modern colourless water-repellent surface treatments, which would allow preservation of the aesthetic appearance of the building. If effective, these surface treatments have the potential to be an enabling technology for the improvement of the energy performance of solid-walls.Although water-repellents can have benefits, in the past, there has been evidence of the poor performance of silicone water-repellent surface treatments associated with the reduction of vapour permeability of the external surface. Recent developments in the chemical composition of water-repellent treatments are claimed to have improved this feature. However, there are uncertainties of long-term performance, particularly on building materials of different mineralogy and porosity.In a broader level, little evidence is available on the positive and long-term adverse effects of water-repellent surface treatments on building energy performance, occupants' health and durability.The research aims to investigate the long-term hygrothermal performance and effectiveness of solid walls with water-repellent surface treatments. In particular, the research will address the following research questions, which are in line with both the Technology and system performance and Comfort, health and well-being ERBE themes:1. What evidence already exists in relation to water-repellent surface treatments in traditional solid walls?2. What is the influence of these treatments on the pore structure of material usually found in external walls of traditional buildings?3. What is the influence of these treatments on the improvement of the thermal transmittance of solid walls?4. What is the long-term hygrothermal performance of solid walls with water-repellent surface treatments?5. What are the long-term adverse and positive effects on solid walls with water-repellent surface treatments?a. What are the long-term harmful and positive effects on reapplying water repellents?6. What is the influence of water-repellent surface treatments on the indoor air quality and energy performance of a solid-walled building?