Factory Building Roof Prefabricated Panels

There are mainly two types of factory building roof prefabricated panels: prefabricated sandwich panels and prefabricated panels manufactured using the 'pre-tensioning method' process, each with its own characteristics and applicable scenarios.

Prefabricated Sandwich Panels

Prefabricated sandwich panels are one-time pressed products from factories, formed by integrating upper and lower color-coated steel plates with a central core material. They are packaged and transported to the construction site, where they are directly hoisted and laid, with the seams fixed, making them standardized finished panels. However, they have several limitations:

• Difficult Maintenance: Prefabricated sandwich panels are pieced together one by one, resulting in numerous horizontal and vertical seams on the roof. Once photovoltaic panels are installed and cover these seams, if water leakage occurs later, a large area of photovoltaic components must be removed for maintenance, leading to high labor and downtime costs.
• Transportation Limitations: Due to the length limitations of truck transportation, they can generally only be transported up to 6-8 meters in length. For large-span factory buildings, multiple overlapping seams must be reserved during installation, increasing the risk of water leakage with more nodes.
• Poor Adaptability: For complex conditions such as renovation of old factory buildings, irregular roofs, or multiple high and low spans, prefabricated sandwich panels come in standard sizes. After cutting and fitting, a large number of edge seams are generated, making sealing difficult and prone to water leakage.

Prefabricated Panels Manufactured Using the 'Pre-tensioning Method' Process

Prefabricated panels manufactured using the 'pre-tensioning method' process involve first tensioning steel bars to the designed strength (prestress) using equipment. After the steel bars are tensioned, concrete is poured. When the cement sets, the retraction force of the steel bars compresses the concrete, giving it ultra-high tensile strength. The manufacturing process is relatively precise:

• Workers first lay a layer of cement and place fixed large foam blocks (connected with iron hooks; there are two viewpoints on the role of foam: lightweight design for weight reduction and sound insulation, or cost-cutting). After pouring, a vibrating rod is used to remove air bubbles.
• Subsequently, curing is carried out, which can be done by continuously steaming with high-temperature steam for four hours in an underground 'sauna room' or by covering with a waterproof membrane for natural curing for one day.
• After curing, they are precisely cut using a CNC electric saw, with a hollow design inside that can be used for running cables and draining sewage.