Translation of Prefabricated Structure Diagram for Old Houses

In the 1980s, old houses generally did not have readily available prefabricated structure diagrams for direct acquisition, but some understanding could be gained through their structural characteristics. Houses from the 1980s were mostly brick-concrete structures. The following provides a detailed introduction from the aspects of structural composition, prefabricated slab conditions, and load-bearing wall characteristics:

Structural Composition

Brick-concrete structure houses from the 1980s were mainly composed of components such as brick walls, reinforced concrete beams, and slabs. The brick walls, as the main load-bearing and enclosing structures, bore the vertical loads of the houses and also served to separate spaces and provide thermal insulation. The reinforced concrete beams were used to bear the loads transmitted from the floor slabs and transfer them to the brick walls or columns.

Prefabricated Slab Conditions

• Types of Prefabricated Slabs: Floor slabs could be either prefabricated slabs or cast-in-place slabs. Prefabricated slabs were floor slab components pre-made in factories and then transported to the construction site for installation. Common types of prefabricated slabs included solid slabs and hollow slabs. Hollow slabs, with holes in the middle, reduced their own weight while ensuring a certain level of strength, saving materials, and were widely used in old houses from the 1980s.
• Installation of Prefabricated Slabs: When installing prefabricated slabs, they needed to be placed on brick walls or beams and fixed with materials such as cement mortar. During the installation process, the flatness and stability of the prefabricated slabs had to be ensured to ensure the normal use of the floor.

Characteristics of Load-Bearing Walls

• Load-Bearing Function: In general brick-concrete structure buildings, the prefabricated slab walls were load-bearing walls and should not be removed or have doors or windows opened in them. Since load-bearing walls bore the weight of the upper part of the house, random removal or modification would damage the overall structural force system of the house, reduce its load-bearing capacity, and potentially lead to serious safety issues such as wall cracking, house tilting, or even collapse.
• Identification Methods: The location of load-bearing walls could be determined by observing the building drawings of the house (if available). One could also knock on the walls; a dull sound generally indicated a load-bearing wall, while a clear sound might indicate a non-load-bearing wall. Additionally, the thickness of the walls could be used for judgment; load-bearing walls were usually thicker, generally over 24 centimeters, while non-load-bearing walls were relatively thinner, approximately 10 - 12 centimeters.