Construction Methods for the Roof of Prefabricated Concrete Houses
The construction methods for the roof of prefabricated concrete houses mainly include steps such as construction preparation, installation of prefabricated roof panels, acceptance of the roof structural layer, construction process flow, and key operational points, as detailed below:
Construction Preparation: In terms of materials, select P.O 42.5 ordinary Portland cement, fine aggregate using medium sand, coarse aggregate using 5-10mm crushed stone, and mixing water from municipal tap water. For the insulation layer, use extruded polystyrene board (XPS), for the waterproof layer, choose SBS modified bitumen waterproof membrane, and for sealing materials, use polyurethane construction sealant. Auxiliary materials include interface treatment agents, isolation layers, and steel mesh sheets. For equipment, prepare forced-action mortar mixers and concrete delivery pumps.
Installation of Prefabricated Roof Panels: After the installation of prefabricated roof panels is complete, panel joint treatment is crucial. Fill the joints with C30 micro-expansion fine aggregate concrete, ensuring the filling depth reaches or exceeds half the panel thickness to ensure structural stability. After filling, cure for 7 days, then conduct a load-bearing capacity test to ensure the installation quality of the roof panels meets requirements.
Acceptance of the Roof Structural Layer: The roof structural layer must pass acceptance, with surface flatness error controlled within ≤5mm/2m. At internal and external corners, use 1:2.5 cement mortar to form an R = 50mm arc to reduce stress concentration. Around pipe roots and embedded parts, fill tightly with expanding fireproof sealant to prevent leakage.
Construction Process Flow: Follow the process of structural layer acceptance → measurement and layout → pipe root sealing → base layer cleaning → watering for moisture → setting out guide marks → laying mortar → vibrating and compacting → surface finishing → curing → dividing joint treatment to ensure each step complies with specifications.
Key Operational Points: During measurement and layout, set guide marks according to a 2% drainage slope, with guide mark dimensions of 50×50mm and spacing of 1.5m×1.5m, directing drainage towards the gutter outlet. Within a 500mm radius around the gutter outlet, increase the slope to 5% to ensure smooth drainage. For pipe root treatment, chisel a circular groove at the root of pipes extending through the roof, clean it, apply an interface treatment agent, then pour fine aggregate concrete to the height of the pipe root to enhance waterproofing at the pipe root.
