Prefabricated Slab Roofing for Houses

Prefabricated slab roofing is a roofing method used in rural or individual residential construction, achieving rapid roofing through on-site installation of factory-prefabricated slabs, but requiring attention to structural safety and waterproofing.

I. Basic Information and Material Selection

Prefabricated slabs include cement prefabricated slabs, lightweight sandwich panels, etc., all of which are produced in a standardized manner in factories and then transported to the construction site for installation. Their core advantages lie in fast construction speed (roofing can be completed in half a day) and reduced on-site wet work, but they must meet the overall design requirements of the house (such as load distribution and span limitations). In terms of cost, cement prefabricated slabs are relatively lower, but the overall cost is still higher than that of traditional cast-in-place structures. Waterproofing is a critical step, requiring the completion of waterproof layer construction before roofing installation to prevent joint leakage.

II. Standardized Construction Process

1. Foundation Construction: Ensure that the foundation is compacted without voids, and strictly control the flatness and strength when pouring the concrete foundation to provide stable support for the columns.
2. Column Installation: After positioning, lay polypropylene film for waterproofing, and fix the prefabricated columns with screws, ensuring that the verticality deviation is ≤3mm.
3. Purlin Installation: After fixing the wooden joists, use angle steel or wooden beams as purlins, with uniform spacing (usually 60-80cm) to ensure uniform distribution of roof loads.
4. Insulation Layer Construction: When selecting extruded polystyrene boards or polystyrene boards, ensure tight adhesion to the purlins, and fill gaps with expanding foam to prevent cold bridge effects.
5. Roofing Installation: Before installing metal or cement tiles, perform secondary waterproofing treatment, lay the slabs in a staggered manner, and reserve a drainage slope (≥2%) to prevent water accumulation.
6. Final Inspection and Acceptance: After cleaning up construction debris, inspect joint sealing, column stability, and other indicators in accordance with the "Building Structural Load Code" and issue an acceptance report.

III. Advantages, Disadvantages, and Applicability

Advantages:

• Short construction period, suitable for emergency housing needs;
• Industrialized production ensures controllable quality and low material loss.

Disadvantages:

• Weak seismic performance: Node connections rely on mechanical fastening, making them prone to displacement during earthquakes;
• Joint vulnerabilities: Slab joints require regular maintenance to prevent air and water leakage;
• Limited durability: Lower steel content and concrete grades may lead to cracking under long-term loads.

IV. Design Life and Maintenance Recommendations

The design life is typically 50 years, but the actual service life depends on regular inspection results. It is recommended to conduct a structural safety assessment every 10 years, focusing on column settlement, joint sealing, and steel corrosion. If the inspection is satisfactory, the house can continue to be used; if there are safety hazards, the service life can be extended through reinforcement (such as adding structural columns) or slab replacement.