How to Understand Shipping Containers: FAQs (Part 1, 2025 Update)

Welcome to Part 1 of our Shipping Container FAQs series—refreshed for 2025. Whether you’re planning to buy a shipping container, compare grades, or optimize storage and delivery, this guide covers the essentials and links you to deeper resources across our site.

What are shipping containers made of?

Most ISO intermodal containers are built from weathering steel (often called COR-TEN) with marine-grade plywood floors supported by steel cross-members. Weathering steel forms a protective oxide layer that slows corrosion—great for long service life when combined with good upkeep. For background on standards, see the International Organization for Standardization (ISO) and the Bureau International des Containers’ overview of container types and construction. For hands-on care, read our Container Maintenance Tips Guide and How to Keep Rust Away From Your Shipping Container in 2025.

Where are shipping containers made?

While standardized containerization has U.S. roots, the majority of new containers are manufactured in China—home to the world’s largest container builders. For sector context and market monitoring, see UNCTAD and the World Shipping Council. If you’re shopping domestically, our nationwide network makes sourcing and shipping container delivery straightforward in 2025.

What sizes do shipping containers come in?

The most common ISO sizes are 20-foot and 40-foot lengths, with standard height (8'6") and High Cube height (9'6"). Need a quick refresher on internal/external dimensions and door openings? Start with our Expert Guide to Shipping Container Sizes and specific pages for 20-foot shipping containers and 40-foot standard containers. If you’re still deciding between heights, compare High Cube vs. Standard.

What types of shipping containers exist?

Beyond standard dry containers, you’ll find refrigerated (reefer) units, open-top, and flat rack containers for oversized cargo. In storage and construction, many customers convert units into offices, workshops, or retail pods. Browse ideas in Shipping Container Architecture & Designs and practical conversion tips in our Shipping Container Transformation Ideas.

How much does a shipping container weigh?

Typical tare weights:

• 20 ft standard: ~4,850–5,100 lbs
• 40 ft standard: ~8,000–8,300 lbs
• 40 ft High Cube: ~8,200–8,800 lbs

Weights vary by manufacturer and spec. For planning delivery access, surfaces, and offloading, see Shipping Container Delivery Times: Everything You Need to Know in 2025 and our site prep checklist.

What do the grades “WWT” and “CW” mean?

WWT (Wind & Water Tight) containers are weather-tight and ideal for storage or conversion projects. CW (Cargo Worthy) containers additionally meet structural criteria for international shipping (including a valid CSC plate). Compare the two in Shipping Container Grades: WWT vs. CW. If you’re buying for export shipping, you’ll want CW; for on-site storage, WWT offers excellent value.

How long do shipping containers last?

With proper siting, paint, and seal maintenance, a storage container can serve for decades. Many customers see 20+ years of useful life in non-marine settings. Maximize longevity with our guides on How Long Shipping Containers Last, first-time cleaning, and floor repair or replacement.

What affects container pricing in 2025?

Prices move with global trade cycles, repositioning costs, and regional supply. For current trends and rate context, see our market notes in 2025 Container Market Outlook and city/state guides like Houston or Chicago container prices. When you’re ready, Get a Quote for an exact door-to-door price.

Quick FAQs

Are shipping containers safe for storage?

Yes—especially WWT and CW grades with intact door gaskets and roof panels. Add lockboxes and puck locks for security, and consider ventilation/desiccants to control humidity. Explore pest-proofing and weather-proofing tips.

Can I modify a container?

Absolutely. Common mods include doors, windows, insulation, and electrical. For concepts and planning tips, see Container Transformation Ideas (2025 Guide).

Should I choose 20 ft or 40 ft?

It depends on access, footprint, and volume. 20 ft units suit tighter sites and distributed storage; 40 ft units offer the best cost per cubic foot. Start with our How to Select the Right Shipping Container Size.

How do I avoid scams when buying online?

Use established vendors, verify addresses and DOT/MC info for delivery partners, and never pay in gift cards or crypto. Our checklist: Buying a Shipping Container Online Safely.

Related Reading

• Expert Guide to Shipping Container Sizes
• Shipping Container Grades: WWT vs. CW
• How Long Do Shipping Containers Last?
• Container Maintenance Tips Guide
• How to Clean Your Shipping Container Before Using It for the First Time

Ready to compare shipping containers for sale—from 20 ft to 40 ft High Cube? Explore our Shipping Container Sales & Services (2025) or Get a Quote for accurate pricing and delivery timing in your area.