Are Storage Containers Watertight?

When it comes to protecting valuable items from moisture and water damage, a common question arises: Are storage containers watertight? Whether you’re storing household goods, business inventory, seasonal items, or survival supplies, ensuring that your containers offer water protection is essential for long-term preservation. The answer to this question depends on the type of container, its construction, and how it is used.

What Does “Watertight” Mean?

First, it’s important to clarify what “watertight” actually means. A watertight storage container is one that prevents water from entering, even when exposed to rain, humidity, or direct splashing. It differs from being “water-resistant,” which means the container can handle moisture or light water exposure but may not withstand heavy rain or submersion.

A truly watertight container will have:

• Sealed edges or seams

• Tight-fitting lids or doors

• Gaskets or rubber seals

• Durable, non-porous materials

Types of Storage Containers and Their Water Protection

There are many different types of storage containers, and their ability to keep water out varies widely.

1. Plastic Storage Bins

Many household storage bins are made from polypropylene or polyethylene plastic. These containers are often water-resistant but not fully watertight. The reason is typically the lid design—most snap-on or interlocking lids don’t form a perfect seal, allowing water or humidity to seep in if they are exposed to the elements.

However, some brands sell watertight storage bins designed with rubber gaskets along the lid rim. These bins are better for outdoor or garage storage where moisture might be an issue.

2. Shipping and Cargo Containers

Large metal shipping containers, like those used on trucks, trains, or ships, are built to be highly watertight. They are designed to withstand rain, waves, and wind. Most shipping containers are equipped with steel construction, weatherproof seals, and lockable doors, making them ideal for outdoor storage.

That said, older or poorly maintained containers may develop rust, door seal failure, or dents, which can compromise their watertight integrity.

3. Specialty Storage Boxes

Some containers are designed specifically to be watertight, such as:

• Pelican cases (used for electronics, photography equipment, or tools)

• Emergency storage boxes

• Military-grade ammo cans

These containers usually feature rubber seals, pressure valves, and rugged clasps, ensuring that water cannot penetrate under normal conditions.

Common Vulnerabilities to Water

Even containers marketed as “watertight” can become vulnerable if:

• The seal is damaged or worn

• The lid is not closed or latched properly

• The container is cracked or warped

• It is exposed to extreme pressure (e.g., submerged in deep water)

For that reason, periodic inspection and maintenance are essential, especially if the container is used outdoors or in humid environments.

Tips for Choosing a Watertight Container

If keeping moisture out is a top priority, consider the following tips:

• Look for products labeled as “watertight” or “IP-rated” (Ingress Protection ratings like IP67 indicate high water and dust resistance)

• Choose containers with gasket seals

• Use desiccants (like silica gel packs) inside containers for added moisture control

• Store containers off the ground to avoid puddles or flooding

• Test your container by placing dry paper towels inside, sealing it, and spraying water on the outside—if the paper stays dry, the container is working

Conclusion

So, are storage containers watertight? Some are—especially those designed with sealing gaskets and rugged construction—but many general-use containers are not fully waterproof. If water damage is a concern, make sure to select containers specifically designed for watertight protection and use them correctly. Whether you’re guarding electronics, important documents, or seasonal decorations, the right container can make all the difference in keeping your items safe and dry.