Precautions for Precast Panel Houses

Precast panel houses require special attention to three main aspects: service life, purchase details, and reinforcement specifications:

I. Dynamic Assessment of Service Life

When of good quality and without external interference, precast panel houses can last 30-50 years; if there are material defects or installation issues, they may only be habitable for a dozen years. For houses with a designed lifespan of 30 years, annual safety inspections are required after 18 years. When purchasing, it is mandatory to check the safety appraisal report. If the remaining lifespan is less than 60%, the seller should be required to sign a reinforcement agreement. After external damage (such as earthquakes or floods), the structural safety must be assessed by a professional agency, and it should not be judged solely by appearance whether it can continue to be inhabited.

II. Strict Verification During Purchase

1. Seismic Performance: Require the seller to provide a seismic report, focusing on checking whether steel plates are added for reinforcement at the connections between floor slabs and whether high-strength grout is used for filling the joints.
2. Material Quality: Use a magnet to detect the diameter of steel bars (which should be ≥8 mm), check the cement packaging label (which should be ≥C25), and be vigilant against violations such as the use of sea sand or recycled steel bars.
3. Construction Techniques: Verify the original construction records to confirm whether seismic columns are added at the corners of beams and columns and whether the materials used for filling the slab joints meet standards.
4. Concealed Works: Conduct a 72-hour closed water test in the kitchen and bathroom, and use an endoscope to inspect whether there is water trapped in the internal cavities of the wall panels.
5. Renovation Restrictions: It is strictly prohibited to modify load-bearing walls. For non-load-bearing wall renovations, a professional agency should calculate the load, and the weight of stacked items should not exceed 200 kg/㎡ (approximately two bags of cement).
6. Property Rights and Maintenance: Check the safety appraisal report, set aside 0.5% of the house price per year as a maintenance fund, inspect the crack width every six months (immediate repair is required if it exceeds 3 mm), and houses with a Class C seismic rating require reinforcement at a cost of 120-200 yuan/㎡.
7. Risk Avoidance: Confirm that the house is not within the demolition planning area for 2025-2035, specify compensation terms in the contract, and purchase structural insurance at an annual rate of 0.3%.

III. Professional and Standardized Reinforcement Construction

1. Scheme Selection: Select materials according to functional requirements. Use carbon fiber cloth or steel plates for reinforcement in areas with insufficient bearing capacity, and adopt steel structure hoops or add supports to improve seismic performance.
2. Construction Details: Ensure complete adhesion and uniform adhesive when pasting carbon fiber cloth, and install steel structure hoops with tight connections and firm fixation.
3. Quality Acceptance: Use ultrasonic or radiographic testing to inspect the reinforced parts to ensure they meet the standards of the "Technical Regulations for Seismic Reinforcement of Buildings".
4. Environmental Management: Take noise reduction and dust prevention measures during construction to avoid affecting surrounding residents. After reinforcement, conduct regular inspections and maintenance, and establish a hidden danger investigation ledger.

All operations must be planned by certified structural engineers, and the construction team must possess special engineering qualifications. Unauthorized renovations by unqualified personnel are strictly prohibited.