Julu Prefabricated Roof Panels
Julu prefabricated roof panels are roofing materials made in advance using rice stone, cement, sand, and coiled steel bars (small-diameter rebar), and are used in some locally built rural houses in the area. The following provides an introduction from the aspects of construction, usage methods, advantages and disadvantages, service life, and evaluation points.
Construction and Materials: The materials used in prefabricated roof panels are essentially the same as those in cast-in-place roofs, but with reduced specifications. Cast-in-place roofs commonly use No. 12 rebar, while prefabricated panels use coiled steel bars or cold-drawn wires; cast-in-place roofs use graded stones, while prefabricated panels use rice stone. This difference in materials makes it easier to prefabricate the panels in advance.
Usage Methods: There are two common methods. One is layered usage, where in two-and-a-half or three-story houses, the lower two floors use prefabricated panels, and the top floor uses a cast-in-place roof. This combination takes advantage of the low cost of prefabricated panels while enhancing the overall integrity and stability of the roof through the cast-in-place roof. The other method is full-house usage, although this is relatively rare.
Advantages and Disadvantages: The advantage is low cost. Among various roofing materials, prefabricated panels are the cheapest option, effectively reducing construction costs. The disadvantages are more pronounced. Poor integrity: Prefabricated panels are placed directly on brick walls and are not integrated with the walls, so they cannot provide tensile force and stability. They are prone to danger in the event of geological disasters. Prone to leakage: Since prefabricated panels are pieced together and connected with concrete or cement mortar in the middle, they are not a monolithic structure, and rainwater can easily seep in through the gaps between the panels. Prone to cracking: Over time, if the house experiences foundation settlement, the prefabricated panels will move and form cracks, which will not only cause leakage but also create psychological fear for the occupants.
Service Life: There is no fixed specific lifespan, as it is affected by various factors. If the raw materials are of good quality and the house does not encounter major natural disasters or foundation settlement, the house can remain stable for many years.
Evaluation Points: In the evaluation of dilapidated houses in Julu, for houses using prefabricated roof panels, the evaluation of the floor panels mainly focuses on deformation and cracking. It is necessary to carefully inspect the cracking of the panel joints of the prefabricated floor panels and use floor load tests to detect possible hidden deformations, thereby judging the safety and stability of the house.
