Construction Method for the Roof of Prefabricated Cement Houses

The construction method for the roof of prefabricated cement houses mainly includes steps such as construction preparation, construction process flow, thermal insulation, and waterproofing treatment, as detailed below:

Construction Preparation

• Material Selection: For cement-based materials, use P.O 42.5 ordinary Portland cement, medium sand as fine aggregate, and 5-10mm crushed stone as coarse aggregate. Functional materials include thermal insulation layers (e.g., extruded polystyrene boards), waterproofing layers (e.g., SBS modified bitumen waterproofing membranes), and sealing materials (e.g., polyurethane construction sealants).
• Roof Panel Treatment: Ensure that the prefabricated roof panels are installed, with the panel joints filled with C30 micro-expansion fine aggregate concrete and subjected to load-bearing capacity tests to ensure structural safety.

Construction Process Flow

• Structural Layer Acceptance: The roof structural layer must pass acceptance tests, with a surface flatness error of ≤5mm/2m, providing a stable foundation for subsequent construction.
• Surveying and Layout: Set up reference blocks according to a 2% drainage slope, with block dimensions of 50×50mm and spacing of 1.5m×1.5m, ensuring smooth roof drainage.
• Pipe Root Sealing: Chisel out annular grooves at the roots of pipes protruding from the roof, clean them, apply an interface treatment agent, and pour fine aggregate concrete to the height of the pipe roots to prevent leakage.
• Base Layer Cleaning: Thoroughly clean the roof base layer to ensure it is free of debris, oil, and other contaminants, ensuring good adhesion quality.
• Mortar Laying: Lay a leveling layer of cement mortar, vibrate it densely, and finish the surface to create a flat base layer.
• Curing: Cure the leveling layer to ensure its strength meets design requirements and prevent cracking.
• Dividing Joint Treatment: Set up dividing joints according to design requirements to prevent roof cracking due to temperature changes or structural deformation.

Thermal Insulation and Waterproofing Treatment

• Thermal Insulation Layer Construction: Use thermal insulation materials with low water absorption, good water repellency, and light weight (e.g., extruded polystyrene boards) laid on the roof structural layer to improve thermal insulation performance.
• Waterproofing Layer Construction: Select flexible waterproofing materials such as SBS modified bitumen waterproofing membranes laid on the thermal insulation layer to ensure waterproofing effectiveness. Alternatively, an inverted roof method can be used, where the waterproofing layer is constructed first, followed by the thermal insulation layer, to extend the service life of the waterproofing layer.

Other Considerations

• Construction Sequence: Generally, the sequence is to accept the roof structural layer → clean the base layer → prepare cement adhesive → construct the leveling layer → construct additional layers → construct the base layer → construct the protective layer → cure.
• Waterproofing Method Selection: For rural self-built houses, choose rigid waterproofing (e.g., waterproofing mortar plastering) or flexible waterproofing (e.g., membrane waterproofing) based on actual conditions to ensure effective roof waterproofing.