The Use of Prefabricated Panels in Single-Story Houses

The use of prefabricated panels in single-story houses presents specific conditions in terms of moisture resistance and building structure, and their application scenarios have evolved with the development of construction technology.

Moisture Resistance Principles and Practices

In terms of moisture resistance, prefabricated panels achieve this through special design. The principle involves leaving a 30 - 50 cm cavity between the foundation and the ground floor. Underground moisture rises into this cavity and dissipates, unable to reach the ground floor, thereby providing moisture resistance. The specific practice is to control the height of the backfill soil at a distance of 30 - 50 cm from the ground after the ground beam is poured, and to compact the backfill soil. However, its moisture resistance has certain limitations. If buried underground for a long time, sharp stones in the backfill soil or accidental damage to the prefabricated panel during construction can allow moisture to penetrate through the break, significantly reducing the moisture resistance effect. Moreover, if the house site is in a low-lying area with a high groundwater level, or if rainwater backs up during the rainy season, keeping the soil saturated for an extended period makes it difficult for the prefabricated panel alone to withstand the continuous moisture pressure, and moisture may still appear on the ground floor.

Building Structure Characteristics

Prefabricated panel houses are constructed using prefabricated panels as the main components. These panels are factory-made cement components, formed by nailing wooden models, laying out steel bars, and pouring cement. They come in two types: solid and hollow, with the hollow structure achieving lightweighting by reducing non-load-bearing concrete. Their advantages include low cost, simple construction, no need for complex processes, operable by ordinary people, and short construction periods. When building a two-story house in rural areas, using prefabricated panels for the first floor and cast-in-place concrete for the second floor can avoid the drawbacks of prefabricated panels, such as the inability to form a unified structure and susceptibility to leaks, while also saving some money. However, the disadvantages are also evident. Existing prefabricated panel houses generally have issues with weak earthquake resistance, poor sound and heat insulation, and a service life of about 30 - 50 years.

Application Scenarios and Development

This building form originated in the early 20th century and was mainly used for floor slabs and roof insulation layers. Most residential buildings constructed in China before 1985 adopted this structure. With the development of construction technology, cast-in-place concrete and prefabricated buildings have gradually replaced traditional prefabricated panel houses. Since 2022, China has implemented a policy of renovating old residential areas, focusing on repairing and renovating prefabricated panel houses and only demolishing those that meet the criteria for dangerous buildings.