How to Prefabricate a House on a Cement Floor

Prefabricating a house on a cement floor requires completing key steps in sequence, including foundation treatment, foundation construction, production and installation of prefabricated components, and roof construction. The specific process is as follows:

1. Foundation Treatment
The foundation is the basis for the stability of the house, and an appropriate method needs to be selected according to the geological conditions:

• Compaction Method: Use a pneumatic hammer or heavy-duty road roller to repeatedly compact the soil layer, increasing the soil density to the bearing capacity standard. This method is suitable for areas with relatively dense soil.
• Soil Replacement Method: Replace loose soil with high-density materials (such as gravel or clay), backfill in layers, and compact to ensure uniform stress on the foundation.
• Piling Method: Embed reinforced concrete piles into soft soil layers to enhance stability through the frictional force or end-bearing capacity between the piles and the soil. This method is suitable for scenarios with soft geology or heavy loads.

2. Foundation Construction
The foundation needs to be closely integrated with the foundation to ensure the safety of the superstructure:

• Site Leveling: Remove weeds and stones, fill in pits and depressions, and ensure that the ground flatness error is ≤ 5 cm.
• Layout and Positioning: Use a tape measure and lime powder to mark the foundation outline, with an error controlled within ± 2 cm.
• Excavation of Foundation Pits: Excavate according to the designed depth, with the bottom width being 10-15 cm wider than the foundation. The slope of the side slopes is adjusted according to the soil quality (e.g., 1:0.5-1:1).
• Cushion Construction: Pour 10-15 cm thick C15 concrete, smooth it out, and let it stand for 24 hours.
• Rebar Binding: Place rebars according to the designed spacing, tie the intersection points of the main rebars and stirrups firmly with iron wire, and ensure that the thickness of the protective layer is ≥ 3 cm.
• Formwork Installation and Concrete Pouring: The formwork needs to be stable without slurry leakage. The concrete strength grade should be no less than C25. After pouring, cover it with plastic film for curing for 7 days.

3. Production of Prefabricated Components
Standardized production of components is the core of improving efficiency:

• Design and Disassembly: Disassemble the building into modules such as columns, beams, and slabs, following a unified modulus (e.g., multiples of 300 mm) to reduce the variety of molds.
• Factory Production: Use high-precision molds to pour concrete, reserve connection holes or slots, and demold after curing to the designed strength.
• Quality Inspection: Check the dimensional deviation of components (≤ ± 3 mm), surface flatness (≤ 2 mm), and the thickness of the rebar protective layer. Only qualified components can leave the factory.

4. Installation of Prefabricated Components
On-site assembly must strictly follow connection specifications:

• Column Installation: After each column is hoisted into place, connect the rebars of the upper and lower columns through sleeve grouting. The grout strength needs to be ≥ 85 MPa.
• Beam Installation: Place the beam end slots on temporary supports on the side of the columns, fix them with corbel plates, and then pour C30 concrete to form a rigid joint.
• Floor Installation: First lay the prefabricated bottom slab, then pour a 5-8 cm thick cast-in-place layer, vibrate and compact it, and then smooth it out.
• Other Components: Prefabricated parts such as stairs and balconies are connected to the main structure by welding or grouting the reserved rebars.

5. Roof Construction
The roof needs to take into account both waterproofing and load-bearing:

• Structural Construction: Hoist the prefabricated roof panels to the top of the columns and fix them with bolts or welding.
• Support Reinforcement: Set up diagonal braces or crossbeams below the roof to ensure that the load is transferred to the walls.
• Cement Pouring: After laying the waterproofing membrane, pour 5-10 cm thick fine aggregate concrete, level it with a scraper and press it smooth, with a curing period of ≥ 14 days.