How to Read the Prefabricated Panel Atlas in House Appraisal

When conducting a house appraisal, reviewing the prefabricated panel atlas requires a professional process, focusing on understanding the atlas structure and appraisal needs. Here are the specific methods:

1. Clarify the Atlas Type and Scope of Application

The prefabricated panel atlases commonly used in house appraisals are primarily based on local standards, such as the series of atlases for prefabricated concrete standard components for assembled residential buildings issued by Sichuan Province, including the 'Standard Base Plate for Prestressed Concrete Steel Pipe Truss Laminated Panels'. These atlases are typically compiled for specific regions or component types, and it is necessary to confirm whether they are applicable to the type of prefabricated panels (such as laminated panels, hollow panels, etc.) in the house under appraisal and the regulatory requirements of the region. For houses built early or with non-standard designs, more general atlases or design drawings may need to be referenced.

2. Grasp the Core Components of the Atlas

The prefabricated panel atlas generally consists of four parts, which need to be consulted in a targeted manner:

1. General Instructions: Include the compilation basis, applicable conditions, material requirements (such as concrete strength grade, steel bar specifications), and construction precautions of the atlas. During the appraisal, it is necessary to focus on verifying whether the prefabricated panels comply with the material and process standards specified in the general instructions, such as whether the concrete has carbonized or whether the steel bars have rusted.
2. Base Plate Selection Table: Lists the dimensions, bearing capacity, applicable spans, and other parameters of prefabricated panels of different specifications. During the appraisal, it is necessary to compare the data in the selection table based on the actual load (such as floor usage, service life) and span requirements of the house to determine whether the prefabricated panels meet the design bearing requirements.
3. Base Plate Template Drawings and Reinforcement Drawings: The template drawings show the plan shape, dimensions, and reserved hole positions of the prefabricated panels; the reinforcement drawings indicate the arrangement, diameter, spacing, and anchoring method of the steel bars. During the appraisal, it is necessary to check whether the actual reinforcement of the prefabricated panels is consistent with the drawings, such as whether the number of steel bars has decreased, whether the spacing is too large, or whether there is cross-sectional loss caused by steel bar corrosion.
4. Laminated Panel Construction Details: Explain the connection nodes, post-pouring strips, and other details of laminated panels (composed of prefabricated base plates and cast-in-place layers). During the appraisal, attention should be paid to the bonding quality between the laminated layer and the prefabricated panel, whether the post-pouring strip has cracked, and whether the node construction complies with seismic requirements.

3. Combine Appraisal Standards with On-Site Measurements

The information in the atlas should be used in conjunction with standards such as the 'Standard for Reliability Appraisal of Civil Buildings' (GB 50292). For example, obtain data on the actual dimensions, concrete strength, and steel bar protective layer thickness of the prefabricated panels through on-site testing, and compare them with the parameters in the atlas to assess whether they meet safety requirements. If the atlas is missing or inconsistent with the actual situation, calculations and reviews should be conducted in accordance with the standards, or professional institutions should be commissioned to conduct structural calculations.