How to Waterproof Container Houses

Waterproofing container houses requires a comprehensive approach involving design, external treatment, sealant application, and regular maintenance. The specific plan is as follows:

I. Waterproofing Strategies at the Design Stage

Site selection and environmental assessment should consider climatic factors (such as rainfall intensity and groundwater level) and on-site drainage conditions to determine the roof slope, drainage outlet positions, and the direction of the external moisture barrier, preventing water accumulation and infiltration. Structural and material matching involves selecting materials with strong anti-permeability for the roof (such as metal panels or waterproof membranes), using waterproof coatings or membranes for walls, sealing gaps while retaining ventilation and moisture-removal channels; insulation materials should have low water absorption, and a breathable waterproof barrier should be installed between the insulation layer and the structure. Steam and moisture control requires mechanical or natural ventilation to prevent water vapor accumulation, with dehumidification systems added in humid areas and proper planning of the direction of the steam isolation layer.

II. Key Points for External Waterproofing

1. Roof Waterproofing

   • Base treatment: Remove debris, dust, and rust from the roof, and apply anti-rust primer after grinding severely rusted areas.
   • Waterproof coatings: Select polyurethane or acrylic coatings, applying 2-3 coats (total thickness 1.5-2.0 mm) with perpendicular cross directions.
   • Waterproof membranes: Use SBS modified asphalt or PVC membranes, laying them from low to high points with an overlap width of ≥100 mm and sealing.
   • Node treatment: Lay an additional 300 mm wide waterproof membrane at weak points such as the connection between the roof and walls and exhaust vents.

2. Exterior Walls and Around Windows and Doors

   • Gap sealing: Fill wall gaps, bolt holes, and welding points with silicone sealant or polyurethane foam sealant.
   • Waterproof coatings: Apply waterproof coatings to the entire wall surface, focusing on applying 2-3 coats at joints.
   • Window and door sealing: Use dedicated sealant strips between frames and wall panels, apply weather-resistant sealant around them, and set drainage slopes on window sills.

3. Bottom Waterproofing

   • Foundation setting: Place the container on a flat and solid foundation higher than the surrounding ground, with drainage ditches around it (slope ≥2%).
   • Moisture barrier layer: Lay a polyethylene moisture barrier film or asphalt felt between the container bottom and the foundation, sealing overlaps and fixing them by turning them up.

III. Selection and Application of Sealants

• Butyl sealant: With a wide temperature resistance range (-40°C to 120°C) and strong aging resistance, it is suitable for long-term outdoor use.
• Chloroprene sealant: Such as Jitai 123, it is convenient for repair and can be painted over, suitable for emergency repairs or scenarios with aesthetic requirements.
• MS sealant: With excellent elasticity (can be stretched 4 times), it adapts to the dynamic swaying of containers, preventing cracking.
• Curing time: Avoid touching for 24 hours after application to ensure complete curing.

IV. Regular Inspection and Maintenance

Inspection cycle: It is recommended to inspect once every six months, with a focus on排查 (which means 'investigation' here, but a more natural English term would be 'checking') before and after the rainy season. Inspection focus: Include checking for cracks in the roof coating, aging of sealants, and whether drainage ditches are unobstructed. Timely repair: Immediately repair minor damages to prevent problems from expanding.