Mould Growth in Residential Building in China: How Big Is the Problem?

The indoor environment plays an important role in the quality of people life, specially now that they spend most of their time indoor. In recent decades, the construction industry in China has had rapid development as has been the growing problem of mould growth in buildings. In this paper, we explore the problem of mould growth in different climate regions of China and analyse the influence of various factors and control method. Firstly, the problem of mould growth occurring in different climate regions in China is reviewed. The prevalence of visible mould spots on the internal surface was found to be higher in Severe Cold and Hot Summer and Cold Winter regions. For the buildings in Severe Cold region, the mould problems often occur during winter seasons as a result of the large temperature difference between room and internal surfaces, causing surface condensation on the wall. For the Hot Summer and Cold Winter region buildings, mould growth was often reported during the spring seasons as a result of humid and warm climate conditions. Secondly, the factors influencing mould growth in a typical building were assessed using simulations and the moisture criteria proposed in Approved Document F. The results showed that the ground floor apartments had a higher risk of having indoor mould contamination compared to top floors. Also, room orientation, indoor temperature and occupancy density could influence mould growth. Finally, the past and current building regulations were assessed and recommendations were provided. With the building regulation introduced, the External wall insulation introduced in new building regulations significantly reduce the risk of mould growth in Severe Cold and Cold regions. However, the regulations were not good enough to completely prevent the development of mould in indoor environment.