Condensation - how dry are shipping containers?

Before you hire a container explain to the agent exactly the type of items being stored.
EG. A cement mixer and bricks will not require a high quality unit, whereas items such as a three piece suite and personal possessions will require a good standard of unit.

The agent should supply you with a container suitable for your requirements.

Condensation occurs when warm moist air cools quickly. In containers the coolest area is usually the interior roof. The moisture can come from:

  1. The items stored are moist (even mattresses,clothing,soft furniture all  hold a certain amount of moisture), dishwashers, washing machines fridges still holding water.
  2. The timber floor in the container is damp.
  3. The container doors are left open in damp /wet conditions.

To help prevent condensation it is recommended that  an Absorbpole is fitted. These are Silica Dessicant  dehumidifiers. They are disposable and, best of all, quite cheap.

They are placed in the container usually hanging from a hook with space around them, the vents in the container or taped over and the Absorbpole then extracts any damp atmosphere as it occurs, normally only one per 20ft container is required. Although two doesn’t hurt, as they only wear out when exposed to moisture. They last under normal conditions for 3 to 6 months. See for full explaination.

Absorbpole - open
Absorbpole - closed

Another method sometimes used is the Grafoed ceiling. This is a product not too dissimilar to Artex to look at. It is sprayed onto the container ceiling and acts like an absorbent taking in any condensation as it forms but letting the moisture out as a vapour when the temperature warms again (you will not notice it working). It does not need replacing and although expensive is often used in container storage. It was designed for large clad roofs like aircraft hangers. See for a full explanation.

Both of these methods work but it also depends on the storer to be careful in what is stored.