How to Drill Holes in Container Houses

Drilling holes in container houses requires careful operation based on the box structure, purpose, and safety regulations. The core principle is to avoid critical load-bearing and force-transfer areas to ensure structural safety and functional integrity.

I. Clarify the Box Structure and Force Transfer Path
The load-bearing system of a container house relies on a steel frame, with the force transfer path being "panel secondary beams → main beams → corner columns → corner fittings → foundation/lower box." Corner fittings are the only stacking force transfer points. Drilling holes in corner fittings, corner columns, or main beams is strictly prohibited, as it can damage the structural integrity, leading to force transfer failure during stacking or local stress concentration. If drilling is necessary, choose non-load-bearing wall panels (such as side panels or end panels) and avoid the throat area connected to the main beams to prevent weakening the connection strength between the wall and the frame.

II. Follow Spatial Combination and Functional Limitations
Drilling holes must meet specific conditions based on the purpose and combination form:

1. Cantilever Structures: If the house adopts a cantilever design (such as L-shaped or U-shaped enclosures), drilling holes in the cantilever section is strictly prohibited, as it can reduce the cross-section and lead to a decrease in bending resistance, causing structural instability.
2. Multi-Layer Stacking: When stacking boxes vertically, corner fittings and corner columns must be aligned and locked up and down. Drilling holes should avoid the contact surfaces between stacked boxes to prevent affecting the uniformity of force transfer.
3. Large Holes Weakening Rigidity: If large holes (such as for doors and windows) are needed, adopt the principle of "staggered and symmetrical arrangement of boxes with and without holes" to balance structural rigidity and avoid excessive local deformation.

III. Control Hole Size and Process

1. Size Limitations: The diameter or side length of the hole should generally not exceed three times the thickness of the wall panel, and reinforcement space should be reserved. For example, the thickness of a standard rock wool sandwich wall panel is 50mm, so the hole diameter should not exceed 150mm.
2. Process Requirements:
   • Use plasma cutting or water jet cutting to avoid high temperatures generated by mechanical drilling that can change the properties of the steel.
   • After cutting, grind the edges of the hole to remove burrs and sharp edges.
   • If the hole is located in an anti-corrosion coating area, apply epoxy zinc-rich primer to prevent corrosion.

IV. Supplementary Regulations for Special Scenarios

1. Fire Protection Requirements: Wall panels in crowded places (such as dormitories and offices) should be filled with Class A rock wool/glass wool. After drilling holes, install fire-blocking materials around the holes to ensure a fire resistance limit of ≥0.5 hours.
2. Waterproofing Treatment: For holes drilled in exterior walls, apply waterproof coating to the inner wall of the hole and install a waterproof cover outside the hole to prevent rainwater infiltration, which can cause the rock wool to absorb water and lose effectiveness.
3. Seismic Fortification: In areas with a seismic fortification intensity of ≥8 degrees, add stiffeners around the holes after drilling to enhance local shear resistance.