How to Accept a Prefabricated Slab House

The acceptance of a prefabricated slab house requires a combination of structural feature inspections, physical parameter measurements, professional equipment scans, and delivery process verifications. The specific methods are as follows:

I. Basic Structural Feature Inspections

1. Observation of Slab Joint Gaps
   Remove the decorative layer to inspect the horizontal joints of the floor slabs. Prefabricated slabs are typically laid longitudinally, with a 20-centimeter overlap between slabs and interspersed steel bars. Each bedroom or living room should have 3-8 evenly spaced horizontal gaps, approximately 50-60 centimeters apart. If the gaps are unevenly distributed or lack cement caulking marks, there may be construction issues.
2. Wall Tapping Sound Feedback
   Tap the ceiling or partition walls with moderate force. Prefabricated slabs will produce a hollow 'dong dong' sound, with no obvious tapping marks on the surface. The regular hexagonal or circular holes inside will make the sound clear and uniform (similar to the sound of a plastic bucket). Avoid the beam support areas, as the sound feedback in reinforced concrete areas will be deep and muffled.

II. Physical Parameter and Drawing Verifications

1. Measurement of Slab Thickness and Hole Spacing
   Lift the baseboard to inspect the edge thickness of the slab. The standard thickness of a prefabricated slab should be 16±2 centimeters, with hole spacing arranged in an arithmetic sequence of 12-18 centimeters. Cast-in-place slabs are generally 11 centimeters thick and have no holes. Bathrooms should use reinforced prefabricated waterproof slabs with a thickness exceeding 20 centimeters, which can be verified by cutting through the prefabricated anchor systems in the walls.
2. Verification of Architectural Drawing Annotations
   Obtain the original design drawings and focus on verifying the structural description clauses. Prefabricated components are usually labeled as 'B1-grade hollow floor slabs', 'YB12 roof panels', etc. The text should include terms such as 'prefabricated component assembly', 'embedded steel plates', and 'prestressed circular hole slabs'. Drawings archived before 2001 can be retrieved as scanned copies from the urban construction archives for verification.

III. Professional Equipment and Operation Verifications

1. Ground-Penetrating Radar Scan
   Hire a construction engineer to use ground-penetrating radar to scan the house frame, distinguishing the ripple differences between the steel bar mesh in cast-in-place structures and the preset metal joints in prefabricated slabs through electronic feedback.
2. Ground Microseismic Feedback Test
   After turning off the air conditioning power, two people alternately jump at different points to trigger low-frequency vibrations. A prefabricated slab room will produce continuous amplitude aftershocks (buzzing for more than 4 seconds), while a cast-in-place solid room will immediately dissipate energy. The operation should be carried out in adjacent unrenovated rooms, avoiding the sensitive period of solid sound transmission before 10 a.m., with the decibel level controlled within the 40-70db safety threshold.

IV. Delivery Process Node Verifications

The following key nodes need to be confirmed:

• Factory Acceptance: Inspect the appearance, doors, windows, and basic functions;
• Transportation and Installation: Check the packing list numbers and quantities, confirm the transportation route and unloading method, and supervise the on-site installation cycle and daily progress;
• Function Debugging: Verify the water and electricity joint debugging (lighting, sockets, drainage), waterproofing and sealing (bathrooms, doors, windows, roof);
• Delivery Documents: Require a third-party organization to provide a CMAP-certified quality inspection certificate, clearly stating the acceptance standards, problem rectification timelines, and warranty descriptions.