How to Build the Roof of a Container Board House

The construction of the roof of a container board house requires following standardized procedures, covering structural assessment, keel installation, material laying, and handling of special parts, with specific steps as follows:

I. Construction Preparation and Structural Assessment

1. Parameter Verification: Confirm the type of base material for the container roof panel (e.g., 1.6~2.0mm thick hot-dip galvanized stamped corrugated steel sheet) and check whether its longitudinal drainage slope (0.5%) meets design requirements.
2. Load Calculation: Calculate the total roof load based on local meteorological data (snowfall, rainfall, wind pressure). For non-accessible roofs, the load should be ≥0.5kN/㎡; for accessible roofs, it should be ≥2.0kN/㎡. The calculation documents must be signed and confirmed by a structural engineer.
3. Technical Disclosure: Clarify construction error thresholds (e.g., slope deviation ≤ ±0.2%), lap dimensions, and sealing requirements. Provide detailed node drawings for special parts such as cross-container seams and flashing.

II. Surveying and Keel Installation

1. Surveying and Layout: Snap the keel reference line along the longitudinal direction of the roof panel. Set horizontal elevation control points every 2m and use the upper surface of the corner fittings as a reference to verify roof height differences, ensuring uniform drainage slope.
2. Keel Installation:
   • Light Steel Frame: Use 8# channel steel for main keels (spacing 500mm) and 50×30mm square steel tubes for secondary keels (spacing 600mm). Nodes should be connected with M12 high-strength bolts, and the contact surfaces should be sandblasted (Sa2.5 grade).
   • Reinforcement Plan: For accessible roofs, weld C-shaped steel or square steel tubes (spacing 600-900mm) between the top beams and lay profiled steel sheets or OSB boards as the base layer.

III. Material Selection and Installation

1. Vapor Barrier: Choose 1.2mm thick HDPE geomembrane or 0.2mm thick polyethylene film to prevent moisture penetration.
2. Insulation Layer:
   • XPS Board: The apparent density should be ≥35kg/m³, with a combustion performance of B1 grade. The thickness should be selected according to climate zones (150mm for severe cold regions and 50mm for hot summer and warm winter regions).
   • Rock Wool Board: The density should be ≥120kg/m³, with a combustion performance of A grade, suitable for projects with high fire protection requirements.
3. Waterproof Layer:
   • First Layer: 1.5mm thick self-adhesive modified asphalt membrane or SBS membrane, with low-temperature flexibility meeting standards (-25℃ without cracks).
   • Second Layer: 1.2mm thick PVC or TPO membrane, with lap welding strength ≥95%.
4. Protective and Decorative Layer: 0.8mm thick galvanized aluminum-zinc color-coated steel sheet (coating ≥20μm) or aluminum-plastic panels, anti-corrosion wood hanging panels.

IV. Handling of Special Parts

1. Cross-Container Seams: Use special sealant or metal pressing strips to seal, ensuring no leakage.
2. Flashing Treatment: Fill the perimeter of roof protrusions (such as vents) with silicone weather-resistant sealant (displacement capacity ±25%), with a curing time ≤7 days.
3. Drainage Design: The slope should be 2%-3%, with single-slope drainage and an eave overhang ≤300mm.

V. Construction Precautions

1. Material Inspection: All materials must be provided with quality certificates and test reports and can only be used after passing sampling inspections.
2. Welding and Fixing: Use E4303 welding rods (diameter 3.2mm). Self-tapping screws should be equipped with EPDM waterproof washers, with a pull-out resistance ≥1.5kN.
3. Fire Protection Requirements: For projects with high fire protection requirements, prioritize the use of A-grade rock wool boards and avoid using combustible insulation materials.