How to Drain Container Houses

The drainage of container houses requires a combination of roof, top structure, indoor, and ground-perimeter designs, achieving efficient drainage through reasonable slopes, drainage systems, and anti-waterlogging measures.

1. Roof Drainage Design

The roof is the primary area for drainage in container houses, and the appropriate method should be selected based on structural characteristics:

• Natural Drainage: Guide rainwater to flow naturally down the roof slope. Ordinary sloped-roof containers should be designed with a slope of at least 5% (5 cm elevation per meter), allowing rainwater to flow along the slope to the lower side and drip directly from the eaves or drain through the edges.
• Organized Drainage: Install drainage gutters and downspout systems. Gutters are fixed along the roof edges with a tilt angle of about 0.5%, connecting to vertical downspouts (commonly using PVC pipes or galvanized steel pipes with diameters of 75mm or 110mm) to direct rainwater to the ground or a sump pit. This method is suitable for areas with heavy rainfall.
• Flat Roof Treatment: For flat-roof containers, a slight slope (at least 2%) should be created on the roof, and drainage outlets should be reserved to prevent waterlogging and leakage. The drainage outlets can be connected to pipes to direct water to the ground drainage system.

2. Top Structure Drainage

Some container houses (such as box-type mobile packing container houses) adopt internal drainage structures:

• Drainage channels are set around the top, and rainwater flows through the channels to the downspouts inside the columns, ultimately being introduced into the underground drainage system. This design hides the pipes and maintains a clean appearance.

3. Indoor Drainage

Indoor drainage should focus on the kitchen and bathroom:

• Kitchen Drainage: A PVC pipe with a diameter of about 50 millimeters should be connected below the sink, and a trap should be installed to prevent odor backflow. The pipe should be tilted at an angle (about 1%-2%) to ensure smooth drainage.
• Bathroom Drainage: Floor drains should be selected for fast drainage speed and good odor prevention performance (such as deep-water seal floor drains); toilet drainage should use a PVC pipe with a diameter of 110 millimeters, directly connected to the external drainage system.

4. Ground and Perimeter Drainage

Drainage systems should be set up around the house to prevent waterlogging:

• Drainage Ditches: Open or concealed ditches should be set around the container. Open ditches are simple to construct, while concealed ditches do not affect the ground appearance. The depth and width of the ditches should be determined based on the site drainage volume (generally, a depth of 20-30 cm and a width of 30-50 cm).
• Site Slope: The ground should be designed with a drainage slope of 0.3%-0.5%, allowing rainwater to naturally flow to the drainage ditches or away from the house, preventing waterlogging from penetrating into the foundation.

5. Other Auxiliary Drainage Methods

• Sloped Roof or Wedge Blocks: By placing wedge blocks on the top of the container or directly adopting a sloped roof design (slope of 2%-5%), rainwater can naturally flow to the drainage outlets.
• Reference to Popular Container Designs: For example, double-story mobile offices often adopt a sloped roof and drainage outlet design, combined with gutters and downspouts, to achieve efficient drainage.

Through the above multi-level drainage designs, container houses can effectively cope with rainwater issues, ensuring structural safety and indoor dryness.