A Cheap Container Can Be the Most Expensive Mistake
Used shipping containers sell for $1,500 to $5,000 depending on size, condition, and location. It is tempting to buy the cheapest one you can find, but a container with hidden damage can cost more to repair than a better container costs to buy. A $1,500 container with severe rust, bent framing, or a compromised floor can require $3,000 to $8,000 in repairs before you even start the conversion.
These seven checks take 30 minutes and can save you thousands.
1. Check the Floor for Soft Spots and Rot
Container floors are marine-grade plywood treated with pesticides. After 15-20 years of use, this plywood can rot, delaminate, or develop soft spots — especially near the door end where rain enters. Walk the entire floor slowly and feel for any flex or softness. Press hard with your heel in suspected areas. A solid floor feels firm and unyielding. A compromised floor flexes noticeably under body weight.
Replacing a container floor costs $1,000 to $2,500. If the floor has significant damage, negotiate the price down accordingly or walk away.
2. Check the Doors
Open and close both cargo doors completely. They should swing freely on their hinges, seal tightly when closed, and lock securely with the locking bars. Doors that stick, sag, or do not seal indicate bent hinges, twisted framing, or a container that was dropped or damaged in transit. Door repairs cost $500 to $1,500. Bent door framing is often a sign of structural damage beyond the doors.
3. Look for Rust — But Know Which Kind Matters
Surface rust (discoloration, light flaking on the exterior) is normal on any used container and is purely cosmetic. Sand it, apply rust converter, prime, and paint. This costs $200 to $500 in materials.
Structural rust (holes, deep pitting, rust that goes all the way through the steel) is a serious problem. Structural rust on the corner posts, bottom rails, or roof panels compromises the container's integrity. Check the bottom rails carefully — they sit closest to the ground and are most prone to severe corrosion. If you can push a screwdriver through any rusted area, that is structural damage requiring welding and plate repairs ($1,000 to $5,000+).
4. Check for Dents and Bowing
Stand at one end and look down the length of the container. The walls should be straight. Large dents or bowing in the side panels may indicate the container was improperly stacked or overloaded. Minor dents are cosmetic. Major deformation can make it difficult to attach interior framing and insulation, adding labor hours and cost to your conversion.
5. Inspect the Roof
Climb up and walk the roof (carefully — container roofs are corrugated steel and can be slippery). Look for patches, dents, rust holes, or areas where water pools. A leaking roof will damage your conversion from above. Roof repairs are possible but awkward — it is much better to buy a container with an intact roof.
Check inside with the doors closed on a sunny day. Any light coming through the roof or walls means there are holes that need repair.
6. Ask About the Container's History
Containers are categorized by condition grade:
One-trip (new): Made in China, shipped to the US with one load, then sold. Best condition, minimal wear. $3,000 to $5,500.
Cargo-worthy (CW): Passed inspection for continued shipping use. Good structural condition with normal cosmetic wear. $2,000 to $4,000. This is the sweet spot for most conversion projects.
Wind and watertight (WWT): No longer certified for shipping but still sealed against weather. May have more dents, rust, and wear. $1,500 to $3,000. Acceptable for stationary conversions if you inspect carefully.
As-is: Sold without any condition guarantee. Inspect extremely carefully. $800 to $2,000. Only buy if you inspect in person and find acceptable condition.
7. Check the Container Size and Type
For most residential conversions, you want a 40-foot high-cube container. The "high-cube" designation means 9 feet 6 inches exterior height (8 feet 10 inches interior), providing adequate headroom after insulation and flooring. Standard-height containers (8 feet 6 inches exterior) leave only about 7 feet 8 inches interior height, which feels cramped after adding insulation overhead.
For a home office or small studio, a 20-foot container provides 160 square feet of usable space — enough for a desk, seating area, and storage.
Where to Buy
Container depots near shipping ports offer the best selection and prices. Search for "shipping container sales" in your area. National dealers like ContainerOne, Shipped.com, and local depot listings on Craigslist and Facebook Marketplace are good starting points. Always inspect in person before buying — photos hide rust and floor damage.
For the complete conversion process after purchasing your container, check out our shipping container conversion guide. Use our cost calculator to estimate your total project cost.