Flat Roof Cement Prefabricated Installation

For the flat roof cement prefabricated installation, it is crucial to focus on the installation steps, advantages and disadvantages, and improvement measures. The key points are as follows:

I. Installation Steps

1. Preparation Stage
   Strictly inspect the dimensions, specifications, and strength of the prefabricated components to ensure they meet the design requirements. Confirm that the positions of the reserved sleeves and reinforcing bars are consistent with the drawings. Simultaneously, prepare tools such as cement mortar, lifting equipment (e.g., cranes), bolts, and sealing materials, ensuring the quality of the materials meets the standards.
2. Foundation Treatment
   Pour a concrete base or strip foundation to ensure a flat and stable foundation, adjusting the dimensions and elevation according to the design requirements. If there is a weak layer in the foundation, reinforce it in advance to prevent structural cracking due to settlement later.
3. Component Lifting and Connection
   Lift components such as columns, beams, and slabs in sequence, prioritizing the installation of load-bearing structures (e.g., main beams) before laying the floor slabs. The connection method should be selected according to the design:

• Bolt Connection: Suitable for fixing between prefabricated components. Ensure that the bolt specifications match the reserved holes and that the tightening torque complies with the specifications.
• Sleeve Grouting: Used for reinforcing bar connections. Control the fluidity of the grout and the curing time to ensure connection strength.
  Seal the wall gaps with sealing materials (e.g., polyurethane foam) to prevent rainwater leakage.

II. Advantages and Disadvantages of Prefabricated Floor Slabs

1. Advantages

• Low Cost: The material prices are low, and the construction period is short (lifting can be completed within one day), making it suitable for budget-limited projects such as rural self-built houses.
• Convenient Construction: Prefabricated components are produced in a standardized manner, resulting in high on-site installation efficiency and reduced labor dependence.

2. Disadvantages

• Poor Waterproof Performance: The joints between floor slabs are prone to becoming leakage channels, requiring additional waterproof treatment (e.g., applying waterproof coatings), but it is difficult to completely solve the problem.
• Low Seismic Resistance: The overall integrity is weaker than that of cast-in-place structures, making it unsuitable for earthquake-prone areas.
• Poor Thermal Insulation: Secondary coverage with materials such as cinder, lime, or insulation boards is required to compensate.

III. Improvement Suggestions

1. Alternative Solution
   If the budget allows, it is recommended to use a cast-in-place cement roof. Although the cost is higher (approximately 3000 yuan for 40-50 square meters), its waterproof and structural performance are superior, and it has better overall integrity and significantly improved seismic resistance.
2. Enhanced Waterproof Measures
   If you insist on using prefabricated floor slabs, you can combine the following methods:

• Waterproof Membrane: Lay SBS modified asphalt membrane with a lifespan of about 15 years, paying attention to joint treatment.
• Color Steel Roof: Install color steel plates (with a lifespan of about 20 years and a cost of 60-80 yuan per square meter), which have both waterproof and heat insulation functions.

IV. Other Precautions

After installation, clean up excess materials to keep the roof tidy. Before the rainy season, focus on inspecting the waterproof layer and joints to prevent leakage due to construction defects.