Dimensions of Prefabricated Panels for Old-Style Houses

The common dimension designs of prefabricated panels for old-style houses need to comprehensively consider load, construction, and material characteristics, mainly divided into standard dimensions and special-scenario dimensions, and must comply with industry norms and error control requirements.

I. Standard Span and Width Combinations

1. Span (Length): The common range is from 3.0 meters to 4.2 meters, increasing in increments of 0.3 meters (e.g., 3.0m, 3.3m, 3.6m, etc.), with a maximum length of up to 6.0 meters. When the span exceeds 4.2 meters, it is necessary to enhance the load-bearing capacity by reinforcing the reinforcement or adopting a double-layer panel design. For example, a residential building project selected prefabricated panels with a span of 3.6 meters, a width of 0.5 meters, and a thickness of 100mm, meeting the load requirements of ordinary residences.
2. Width: Fixed at 0.5 meters or 0.6 meters, with a few projects using 0.4-meter narrow panels (requiring an increased number of splices). The width design of 0.5 meters or 0.6 meters facilitates single-person handling, improving construction efficiency; overly wide panels require mechanical assistance for installation.
3. Thickness: Typically ranges from 80mm to 120mm, with areas subject to heavier loads (such as industrial plants) possibly increasing to 150mm. The thickness selection needs to be combined with structural calculations to ensure a balance between safety and economy.

II. Non-Standard Dimensions for Special Scenarios

1. Large-Span Structures: In buildings such as auditoriums and warehouses, spans can reach 6.0 meters, requiring the use of prestressed technology or increasing the panel thickness to over 150mm to resist greater bending moments.
2. Irregular Space Adaptation: For L-shaped or curved layouts, trapezoidal or fan-shaped panels can be customized, but they require on-site splicing or combination of small panels, increasing construction complexity.
3. Light-Load Areas: Balconies and corridors may use thin panels with a span of 2.4 meters and a thickness of 80mm, but structural calculations are required to verify safety and avoid deformation or cracking due to insufficient load-bearing capacity.

III. Industry Norms and Restrictions

1. Transportation Restrictions: The length of prefabricated panels usually does not exceed 12 meters; otherwise, segmented production or special transportation plans need to be formulated to avoid damage during transportation.
2. Material Economy: Priority is given to standard dimensions (e.g., a span of 3.3 meters is more economical in terms of concrete usage than 3.5 meters), reducing waste of offcuts and lowering project costs.

IV. Dimension Tolerance and Quality Control

According to the "Quality Inspection Standard for Prefabricated Concrete Components" (GB 50204-2015), the allowable tolerances are:

• Length: ±5mm
• Width: ±3mm
• Thickness: ±3mm
• Surface Flatness: ≤3mm/m

Strict quality control ensures the installation accuracy of prefabricated panels, avoiding difficulties in splicing or structural safety hazards due to dimensional deviations. Old-style prefabricated panels are still suitable for renovation projects or projects with limited budgets due to their low cost and high construction proficiency.