Treatment of Cement Prefabricated House Roof

The treatment of cement prefabricated house roofs should be carried out comprehensively from four aspects: reinforcement, construction, thermal insulation, and gap treatment. The specific methods are as follows:

I. Reinforcement Treatment

Take targeted measures for different structural types:

1. Floor and Roof Reinforcement: If the prefabricated panels are pulled apart or damaged, use cement mortar to refill and add steel bars for thickening. When the roof shifts, use iron pipes for support or add brick piers. For brick-wood houses, use "clout nails" to strengthen the connection between the wooden roof truss and the purlins, use backing plates to reinforce the gable walls and purlins, and add diagonal braces between wooden columns. Tilted roofs need to be straightened, and decayed wooden roof trusses should be provided with additional beams and columns.
2. Reinforcement of Protruding Parts: Install vertical tie bars for chimneys, parapet walls, and other parts, and remove unnecessary attachments to reduce the impact of wind loads.
3. Wall Reinforcement: When load-bearing and non-load-bearing walls crack or tilt, use methods such as brick removal and joint filling, steel bar reinforcement, setting up "wall cables" or attached columns. Non-load-bearing walls can be provided with additional buttresses to enhance stability.

II. Construction Treatment

1. Material and Equipment Preparation:
   • Select P.O 42.5 ordinary Portland cement for the cement, with a storage period not exceeding 3 months. Cement that is damp and caked is prohibited. The fine aggregate is medium sand with a silt content of ≤3%, and the coarse aggregate is 5-10mm crushed stone.
   • The thermal insulation layer uses extruded polystyrene board (XPS), the waterproof layer uses 4mm thick SBS modified asphalt waterproof membrane, and the sealing material is polyurethane construction sealant.
   • Equip with forced-action mortar mixers, concrete pumps, and other equipment to ensure construction efficiency.
2. Process Flow: Structural layer acceptance → Surveying and setting out → Pipe root sealing → Base layer cleaning → Water spraying for wetting → Screed strip and screed bar setting → Mortar laying → Vibrating and compacting → Surface finishing → Curing → Dividing joint treatment.
   • During surveying and setting out, set screed strips according to a 2% drainage slope, and increase the slope to 5% within a 500mm radius around the gutter outlet.
   • For pipe root treatment, chisel a 20mm deep circular groove at the root of pipes with a diameter of ≤100mm, apply an interface treatment agent, and then pour with C25 fine aggregate concrete (mixed with 5% expansion agent).

III. Thermal Insulation Treatment

1. Material Selection: Preferably use polystyrene boards, rock wool boards, or polyurethane foam, which should have fire-resistant and moisture-proof properties.
2. Laying Requirements: Evenly lay 20-30cm thick thermal insulation materials on a dry and clean roof to ensure no gaps. Cover the surface with a waterproof layer (such as waterproof membrane or coating), and then carry out leveling and decoration.
3. Maintenance Points: Regularly check the condition of the thermal insulation layer, repair damaged areas in a timely manner, and avoid long-term water accumulation or exposure to the sun.

IV. Gap Treatment

1. Initial Filling: Use foam glue to fill the roof gaps to ensure a flat surface.
2. Waterproof Reinforcement: Apply waterproof coating or lay waterproof membrane on the surface of the foam glue to form double protection and prevent leakage.