Container grades describe condition, not size. In descending order of quality the ladder runs: one-trip (effectively new), IICL-5 (strictest used standard), cargo worthy (certified fit for ocean shipping), wind and water tight (weatherproof but not shipping-certified), and as-is (known defects, priced accordingly).
For ground storage on your own property, wind and water tight does the job. If the container will ever be loaded onto a ship, you need cargo worthy with a valid CSC plate — nothing less will move. If you are converting it into an office, shop or living space, one-trip is usually worth the premium because you are not paying a fabricator to chase rust.
Last reviewed: July 2026.
The Grades, Defined
One-trip (often marketed as “new”)
A one-trip container was built in the last year or so, loaded with cargo at the factory end, and shipped once to reach the market where it is now being sold. That single voyage is what makes it available in North America at all — nobody builds these domestically at scale, and moving an empty box across the Pacific costs the same as moving a loaded one, so manufacturers ship them full.
What you get: original factory paint, no through-rust anywhere, a clean undamaged floor, door gaskets that seal properly, hardware that operates without a pry bar, and a valid CSC plate. Cosmetically there may be minor scuffs and a few small dents from handling — that is normal and does not change the grade.
Buy one-trip when appearance matters, when the container is going somewhere visible, or when you are doing a conversion. Cutting windows and doors into a rusted box means grinding, treating and repainting before you can even start, and that labour typically costs more than the difference between grades.
IICL-5
IICL-5 is an inspection standard published by the Institute of International Container Lessors, used by leasing companies to define acceptable condition when a container comes off lease. It is the tightest used grade in common circulation — tighter tolerances on dents, corrosion and repairs than cargo worthy.
In practice IICL-5 units are lightly used ex-lease containers, often five years old or less. They are less common on the retail market than one-trip or cargo worthy, and when they do surface they price close to one-trip. Worth taking if you find one at the right number, but not worth waiting for.
Cargo worthy (CW)
Cargo worthy means a qualified surveyor has inspected the container and certified it structurally sound and fit to carry cargo in international transport. It requires an intact, legible CSC safety approval plate — the metal plate on the left door mandated by the IMO’s International Convention for Safe Containers — and, depending on the container’s age, a current re-inspection under an approved examination scheme.
A cargo worthy box will typically be 8 to 15 years old. Expect surface rust, dents, previous patch repairs, faded or mismatched paint, and a floor with wear and stains. What it will not have: holes, structural cracks, bowed or delaminated flooring, non-operating doors, or damaged corner castings.
The key point buyers miss: cargo worthy is a certification, not an adjective. If a seller calls a container cargo worthy, ask who surveyed it and when, and ask for the certificate. A container described as “cargo worthy” with no survey behind it is a wind and water tight container with better marketing.
Wind and water tight (WWT)
WWT means the container keeps weather out. No daylight through the walls or roof, doors close and seal, no active leaks. It is the standard grade for static storage and it is what most used containers on the domestic market actually are.
The honest caveat: there is no issuing body for WWT. No independent organisation defines or certifies it. It is a seller’s representation, which means its value depends entirely on the seller’s willingness to stand behind it. Two containers both advertised WWT can differ enormously — one with light surface rust and tidy repairs, the other with heavy pitting, a floor patched with sheet metal, and doors that need two people and a bar.
That is why you buy WWT on inspection, on photographs of the actual unit, or from a supplier who backs the description. HR Trailer Service LLC stocks used wind and water tight containers alongside new one-trip units and carries a 30-day guarantee — the guarantee is the part that makes a WWT purchase safe. Browse current stock across sizes in our shipping containers inventory.
As-is
As-is containers are sold with disclosed defects: holes, a soft or damaged floor, doors that do not operate, significant structural damage, or a missing CSC plate. Price reflects it. These make sense if you are cutting the box up for material, using it as a blast wall or fill container, or you have a fabricator and a plan.
They do not make sense for storage. A container with a roof hole will destroy what you put in it, and roof repairs on a corrugated steel panel are not a weekend job for most people.
Grade Comparison
| Grade | Typical age | Valid CSC plate | Ocean shipping | Best use |
|---|---|---|---|---|
| One-trip | Under 2 years | Yes | Yes | Conversions, visible sites, long-term ownership |
| IICL-5 | 2–8 years | Yes | Yes | Near-new condition at used pricing |
| Cargo worthy | 8–15 years | Yes, required | Yes | Export, repositioning, storage with resale value |
| Wind & water tight | 10–20 years | Not required | No | On-site storage, job sites, agricultural use |
| As-is | Varies | No | No | Material salvage, non-weather-critical uses |
What Actually Separates the Grades
When a surveyor grades a container, these are the areas being assessed. They are also what you should be looking at during your own walk-around.
- Roof. The single most important panel and the one people forget to inspect. Ponding water and standing debris cause pitting from the top down. Climb up or get a photo from above. Roof rust is the failure mode that ruins stored contents.
- Floor. Marine plywood, typically 1 1/8 inch, laid over steel cross-members. Look for delamination, soft spots, gouges from forklift tines and previous patches. A sound floor carries a forklift; a compromised one does not.
- Doors and gaskets. All four locking bars should turn with hand pressure. Gaskets should be pliable, not cracked and flattened. Doors that bind almost always mean the container is sitting out of level, but they can also mean a racked frame.
- Corner castings and rails. These carry every load path in the container. Cracks, tears or heavy deformation at the castings drop a container to as-is regardless of how good the panels look.
- Corrosion depth. Surface rust on a container is normal and cosmetic. Pitting that has gone through, or scaling that flakes to reveal thinned steel, is not. The distinction is depth, not area.
- Repairs. Properly welded patch plates are acceptable at cargo worthy and WWT. Riveted patches, sheet-metal screws and sealant-only repairs are not.
Which Grade Should You Buy?
Buy one-trip if you are converting the container, it will sit somewhere customers or neighbours can see it, you want maximum service life, or you want the least risk. It is also the right call for a first-time buyer who cannot inspect in person and does not want to learn container corrosion assessment on their own money.
Buy cargo worthy if the container will ever be loaded on a ship, rail intermodal service, or moved internationally. Without the CSC certification it will not be accepted. CW is also a reasonable middle ground for storage when resale value matters — a certified box holds value better than an uncertified one.
Buy wind and water tight if the container is going to sit on your property and hold tools, equipment, inventory or feed, and appearance is secondary to cost per square foot. This is the majority of buyers. A WWT 20ft container is the most cost-effective secure storage available anywhere, and a WWT 40ft container gives you double the space for well under double the money.
For tight sites where a 20ft will not fit, the same grading applies to smaller units — an 8ft container or 10ft container can be had in one-trip or used condition, though note that cut-down mini containers will not carry a valid CSC plate regardless of how good they look.
Grade Terms That Mean Nothing
Be skeptical of these when you see them in a listing, because none of them map to a defined standard:
- “Grade A” / “Grade B” / “Premium” — invented seller vocabulary. Ask what it means in terms of the real grades above.
- “Refurbished” — could mean a full sandblast, repair and repaint, or it could mean a coat of paint over rust. Ask what was done.
- “Like new” — not one-trip. If it were one-trip the seller would say so, because one-trip commands more money.
- “Certified” with no issuing body named — meaningless. Certified by whom, to what standard, on what date?
The counter to all of it is the same: ask for photographs of the specific unit you are buying — not stock images — including the roof, the interior with doors open, the floor, and a legible shot of the CSC plate. Any legitimate seller will provide them.
Grade, Delivery and Total Cost
One last practical note. Grade affects the container price, but freight often costs as much as the grade difference, so factor it in when comparing. A cheap as-is container two states away can easily land more expensive than a better unit sourced closer.
Delivery method matters too. Containers of any grade are usually set down by tilt-bed trailer, which requires no crane at your end — see our tilt deck trailers. If you already have lifting equipment on site, a flatbed or a container chassis may be cheaper. We quote flat-rate freight to the lower 48 from Wickenburg, Arizona, so the landed number is known before you commit. Current inventory across all grades and sizes is on the shop page.
Frequently Asked Questions
What does wind and water tight mean for a shipping container?
Wind and water tight means the container has no holes, the doors seal, and weather stays out. It is not a certified standard — no independent body defines or issues it, so it is a seller’s representation. WWT containers are suitable for on-site storage but cannot be used for international ocean shipping.
What is the difference between cargo worthy and wind and water tight?
Cargo worthy is certified by a qualified surveyor and requires a valid CSC safety approval plate, making the container legal for international shipping. Wind and water tight only means the box keeps weather out, with no certification behind it. Cargo worthy units are structurally verified; WWT units are not.
Is a one-trip container actually new?
Effectively yes. A one-trip container was built within roughly the last year and carried cargo on a single voyage to reach the market where it is sold. It has factory paint, an undamaged floor, sealing gaskets and a valid CSC plate. Minor handling scuffs are normal and do not change the grade.
What grade of container do I need for storage on my property?
Wind and water tight is sufficient for static storage of tools, equipment, inventory or feed. It is the most cost-effective option per square foot. Choose one-trip instead if appearance matters, if the container is visible to customers or neighbours, or if you plan to convert it.
Do I need a CSC plate on my container?
Only if the container will move in international transport by ship or intermodal rail. For a container sitting permanently on your property, a CSC plate is not required. It does help resale value, since a certified box can re-enter shipping service and an uncertified one cannot.
How long does a used shipping container last?
Containers typically leave ocean service after 10 to 15 years, then serve decades more in static storage. Life depends almost entirely on the roof and on keeping the container off bare soil. Set it on level piers with drainage away from the footprint and address surface rust before it pits through.
Can I convert a wind and water tight container into an office or shop?
You can, but budget for prep. Cutting openings in a rusted container means grinding, treating and repainting before framing starts, and that labour often exceeds the price gap to a one-trip unit. For conversions, a one-trip high cube is usually the cheaper path once total cost is counted.