Container House Roof Leakage

The common causes and solutions for roof leakage in container houses are as follows:

Common Causes

1. Fastener Issues
   During installation and use, stepping on the roof can cause fasteners to loosen, or aging of the waterproof gaskets can lead to leakage at the fastener positions. For example, when roof screws loosen due to vibration, rainwater seeps in through the gaps.

2. Waterproof Material and Construction Defects

• Using inferior waterproof materials, such as low-weather-resistant sealants, which are prone to cracking under the influence of ultraviolet rays or temperature variations.
• Unreasonable construction techniques, such as not fully applying waterproof adhesive at the joints of the roof panels or not reinforcing the edge closures.
• Aging of the house leads to a decline in material performance, such as rubber seals becoming hard and falling off.

3. Structural Deformation and Cracks

• External loads (wind, snow) or thermal expansion and contraction cause deformation of the roof panels, widening the joints and damaging the original waterproof layer.
• When holes are made in the roof panels for installing fans or exhaust pipes, improper treatment of the surrounding cracks or the generation of new cracks due to vibration during use.

4. Drainage System Failure

• The gutter has no horizontal slope or the outlet design is unreasonable, causing water to back up during heavy rain.
• Inadequate anti-corrosion treatment of the gutter leads to rust and erosion, or debris blocks the outlet, resulting in water leakage or backflow. For example, during a heavy rain in Nagoya, a container house experienced indoor leakage due to the inability of the gutter to drain accumulated water.

Solutions

1. Fastener Maintenance
   Regularly inspect the roof fasteners, retighten loose screws, and replace aging waterproof gaskets. Use spring washers in high-vibration areas (such as around fans) to enhance the anti-loosening effect.

2. Waterproof Layer Repair and Reinforcement

• Remove damaged waterproof materials, reapply high-elastic waterproof coatings (such as polyurethane), and reinforce with polyester fabric.
• Use the 'one fabric, three coats' technique for the joints of the roof panels: first apply a base treatment agent, lay the waterproof membrane, and then apply two coats of sealant.
• For the hole openings, use dedicated waterproof sleeves, seal the surroundings with structural adhesive, and perform flashing treatment.

3. Structural Reinforcement and Crack Treatment

• Correct deformed roof panels and replace severely deformed ones if necessary.
• For crack treatment, use the 'filling + patching' method: widen the crack into a V-shaped groove, fill it with elastic sealant, and attach butyl rubber waterproof tape to the surface.

4. Drainage System Optimization

• Adjust the slope of the gutter to be no less than 1% to ensure smooth drainage.
• Regularly clean debris from the gutter, apply anti-corrosion coatings to rusted areas, or replace with stainless steel gutters.
• Install filters at the outlets to prevent large debris from blocking them.